NCBI Conserved Domain Search

Pleckstrin homology domain;

Pssm-ID: 465218 Cd Length: 143 Bit Score: 279.28 E-value: 6.44e-89

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 644 VQCEGLAEQLIFNSLTNCLGPRKLLHSGKLYKTKSNKELHGFLFNDFLLLTYMVKQFAvSSGSEKLFSSKSNAQFKMYKT 723
Cdd:pfam16652   1 VQCEGLSEQLVFNSLTNCLGPRKLLHSGKLYKVKSNKELVGFLFNDFLLLTQPVKPLS-SAGTDKLFSSKSNIQYKMYKT 79

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 724 PIFLNEVLVKLPTDPSSDEPVFHISHIDRVYTLRTDNINERTAWVQKIKAASEQYIDTEKKKRE 787
Cdd:pfam16652  80 PIFLNEVMVKLPTDPSSSEPTFQLSHIDRVYTLKAESPNERTAWVKKIKEASELYIETEKKKRE 143

C2 domain present in Intersectin; A single instance of the C2 domain is located C terminally in the intersectin protein. Intersectin functions as a scaffolding protein, providing a link between the actin cytoskeleton and the components of endocytosis and plays a role in signal transduction. In addition to C2, intersectin contains several additional domains including: Eps15 homology domains, SH3 domains, a RhoGEF domain, and a PH domain. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. The members here have topology I.

Pssm-ID: 176021 [Multi-domain] Cd Length: 136 Bit Score: 270.41 E-value: 9.45e-86

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 787 EKAYQARSQKTSGIGRLMVHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCL 866
Cdd:cd08375     1 EKAYLARSQRASGIGRLMVVIVEGRDLKPCNSNGKSDPYCEVSMGSQEHKTKVVSDTLNPKWNSSMQFFVKDLEQDVLCI 80

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 867 TLFDRDQFSPDDFLGRTEIPVAKIRTE-QESKGPMTRRLLLHEVPTGEVWVRFDLQ 921
Cdd:cd08375    81 TVFDRDFFSPDDFLGRTEIRVADILKEtKESKGPITKRLLLHEVPTGEVVVKLDLQ 136

Intersectin Pleckstrin homology (PH) domain; ITSNs, an adaptor protein family, play a role in endo- and exocytosis, actin cytoskeleton rearrangement and signal transduction. There are two human ITSN genes: ITSN1 and ITSN2. They share significant sequence identity and a similar domain structure having both short and long isoforms produced by alternative splicing. The short isoform (ITSN-S) consists of two Eps15 homology domains (EH1 and EH2), a coiled-coil region (CCR) and five Src homology 3 domains (SH3A-E). The EH domains bind to Asn-Pro-Phe motifs and are implicated in endocytosis and vesicle transport. The SH3 domains bind to proline-rich sequences and are commonly found in proteins implicated in cell signalling pathways, cytoskeletal organization and membrane traffic. The long isoform (ITSN-L) contains three additional C-terminal domains, a Dbl homology domain (DH), a Pleckstrin homology domain (PH) and a C2 domain. The tandem DH-PH domains are present in all Dbl family of GEFs. ITSN acts specifically on Cdc42 through its DH domain with no portion of the PH domain making contact with Cdc42. This is in contrast to Dbs which requires the PH domain for full catalytic activity. The ITSN PH domain binds phosphoinositides. C2 domains are usually involved in Ca2+-dependent and Ca2+-independent phospholipid binding. There are more than 30 proteins that interact with ITSNs. ITSN-S is present in mammals, frogs, flies and nematodes, while ITSN-L is present only in vertebrates. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

Pssm-ID: 270084 Cd Length: 132 Bit Score: 241.97 E-value: 3.32e-75

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 652 QLIFNSLTNCLGPRKLLHSGKLYKTKSNKELHGFLFNDFLLLTYMVKQFAvSSGSEKLFSSKSNAQFKMYKTPIFLNEVL 731
Cdd:cd13264     1 QLIFNSVTNCLGPRKFLHSGKLYKAKSNKELYGFLFNDFLLLTQPIKPLG-SSGNDFVFDNKANIQYKMYKTPIFLNEVL 79

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 732 VKLPTDPSSDEPVFHISHIDRVYTLRTDNINERTAWVQKIKAASEQYIDTEKK 784
Cdd:cd13264    80 VKLPTDPSGDEPIFHISHIDRVYTLRAESINERTAWVQKIKAASELYIETEKK 132

Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases; Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases Also called Dbl-homologous (DH) domain. It appears that PH domains invariably occur C-terminal to RhoGEF/DH domains. Improved coverage.

Pssm-ID: 214619 [Multi-domain] Cd Length: 180 Bit Score: 168.25 E-value: 6.63e-48

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  446 IHELIQTEERYMADLQLVVEVFQKRM-AESGFLTEGEMALIFVNWKELIMSNTKLLKALRVRKKTggEKMPVQMIGDILA 524
Cdd:smart00325   2 LKELLQTERNYVRDLKLLVEVFLKPLkKELKLLSPNELETLFGNIEEIYEFHRDFLDELEERIEE--WDDSVERIGDVFL 79

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  525 AELSHMQAYIRFCSCQLNGAALLQQKtDEDTDFKEFLKKLASDPRCKGMPLSSFLLKPMQRITRYPLLIRSILENTPESH 604
Cdd:smart00325  80 KLEEFFKIYSEYCSNHPDALELLKKL-KKNPRFQKFLKEIESSPQCRRLTLESLLLKPVQRLTKYPLLLKELLKHTPEDH 158

                          170       180
                   ....*....|....*....|..
gi 1370477838  605 ADHSSLKLALERAEELCSQVNE 626
Cdd:smart00325 159 EDREDLKKALKAIKELANQVNE 180

Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases; Also called Dbl-homologous (DH) domain. It appears that PH domains invariably occur C-terminal to RhoGEF/DH domains.

Pssm-ID: 238091 [Multi-domain] Cd Length: 181 Bit Score: 167.86 E-value: 1.07e-47

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 442 RQGYIHELIQTEERYMADLQLVVEVFQKRMAESG-FLTEGEMALIFVNWKELIMSNTKLLKALRVRKKTGGekMPVQMIG 520
Cdd:cd00160     1 RQEVIKELLQTERNYVRDLKLLVEVFLKPLDKELlPLSPEEVELLFGNIEEIYEFHRIFLKSLEERVEEWD--KSGPRIG 78

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 521 DILAAELSHMQAYIRFCSCQLNGAALLQQKTDEDTDFKEFLKKLasDPRCKGMPLSSFLLKPMQRITRYPLLIRSILENT 600
Cdd:cd00160    79 DVFLKLAPFFKIYSEYCSNHPDALELLKKLKKFNKFFQEFLEKA--ESECGRLKLESLLLKPVQRLTKYPLLLKELLKHT 156

                         170       180
                  ....*....|....*....|....*
gi 1370477838 601 PESHADHSSLKLALERAEELCSQVN 625
Cdd:cd00160   157 PDGHEDREDLKKALEAIKEVASQVN 181

RhoGEF domain; Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases Also called Dbl-homologous (DH) domain. It appears that pfam00169 domains invariably occur C-terminal to RhoGEF/DH domains.

Pssm-ID: 459876 [Multi-domain] Cd Length: 176 Bit Score: 164.01 E-value: 2.06e-46

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 446 IHELIQTEERYMADLQLVVEVFQKRMAESGFLTEGEMALIFVNWKELIMSNTKLLkaLRVRKKtggEKMPVQMIGDILAA 525
Cdd:pfam00621   2 IKELLQTERSYVRDLEILVEVFLPPNSKPLSESEEEIKTIFSNIEEIYELHRQLL--LEELLK---EWISIQRIGDIFLK 76

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 526 ELSHMQAYIRFCSCQLNGAALLQQKTDEDTDFKEFLKKLASDPRCKGMPLSSFLLKPMQRITRYPLLIRSILENTPESHA 605
Cdd:pfam00621  77 FAPGFKVYSTYCSNYPKALKLLKKLLKKNPKFRAFLEELEANPECRGLDLNSFLIKPVQRIPRYPLLLKELLKHTPPDHP 156

                         170       180
                  ....*....|....*....|
gi 1370477838 606 DHSSLKLALERAEELCSQVN 625
Cdd:pfam00621 157 DYEDLKKALEAIKEVAKQIN 176

Fifth Src homology 3 domain (or SH3E) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212929 [Multi-domain] Cd Length: 54 Bit Score: 128.56 E-value: 1.54e-35

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 362 CQVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11996     1 CQVIAMYDYTANNEDELSFSKGQLINVLNKDDPDWWQGEINGVTGLFPSNYVKM 54

Fourth Src homology 3 domain (or SH3D) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fourth SH3 domain (or SH3D) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212927 Cd Length: 59 Bit Score: 128.51 E-value: 1.69e-35

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1370477838 289 IAQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARGKKRQKGWFPASHVKLL 347
Cdd:cd11994     1 IAQVTTAYVASGVEQLSLSPGQLILILKKNSSGWWLGELQARGKKRQKGWFPASHVKLL 59

Second Src homology 3 domain (or SH3B) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The second SH3 domain (or SH3B) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212923 [Multi-domain] Cd Length: 52 Bit Score: 124.00 E-value: 5.22e-34

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11990     1 KAQALCSWTAKKDNHLNFSKNDIITVLEQQENWWFGEVHGGRGWFPKSYVKL 52

Third Src homology 3 domain (or SH3C) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (SH3C) of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212925 Cd Length: 52 Bit Score: 123.97 E-value: 5.38e-34

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQKDGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11992     1 EYIALYPYSSSEPGDLTFNEGEEILVTQKDGEWWTGSIEDRTGIFPSNYVRP 52

Fourth Src homology 3 domain (or SH3D) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212773 [Multi-domain] Cd Length: 58 Bit Score: 115.90 E-value: 4.39e-31

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 289 IAQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARGKKRQKGWFPASHVKL 346
Cdd:cd11839     1 IAQVIAPFTATAENQLSLAVGQLVLVRKKSPSGWWEGELQARGKKRQIGWFPANYVKL 58

Fifth Src homology 3 domain (or SH3E) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212774 [Multi-domain] Cd Length: 53 Bit Score: 115.59 E-value: 4.66e-31

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11840     1 QVIALFPYTAQNEDELSFQKGDIINVLSKDDPDWWRGELNGQTGLFPSNYVEP 53

Third Src homology 3 domain (or SH3C) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. The SH3C of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212772 [Multi-domain] Cd Length: 52 Bit Score: 115.59 E-value: 4.97e-31

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQKDGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11838     1 EYIALYPYESNEPGDLTFNAGDVILVTKKDGEWWTGTIGDRTGIFPSNYVRP 52

Fourth Src homology 3 domain (or SH3D) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212926 Cd Length: 65 Bit Score: 115.60 E-value: 6.91e-31

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 285 KKPEIAQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARGKKRQKGWFPASHVKLLGP 349
Cdd:cd11993     1 KKPEIAQVIASYTATGPEQLTLAPGQLILIRKKNPGGWWEGELQARGKKRQIGWFPANYVKLLSP 65

Fifth Src homology 3 domain (or SH3E) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212928 [Multi-domain] Cd Length: 54 Bit Score: 104.27 E-value: 3.98e-27

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 362 CQVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11995     1 CQVIGMYDYTAQNDDELAFSKGQIINVLNKEDPDWWKGELNGQVGLFPSNYVKL 54

C2 domain; The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 175973 [Multi-domain] Cd Length: 102 Bit Score: 105.61 E-value: 5.72e-27

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKACKPNGKSNPYCEISMGS-QSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDDFLG 881
Cdd:cd00030     1 LRVTVIEARNLPAKDLNGKSDPYVKVSLGGkQKFKTKVVKNTLNPVWNETFEFPVLDPESDTLTVEVWDKDRFSKDDFLG 80

                          90
                  ....*....|....*
gi 1370477838 882 RTEIPVAKIRTEQES 896
Cdd:cd00030    81 EVEIPLSELLDSGKE 95

Second Src homology 3 domain (or SH3B) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212771 [Multi-domain] Cd Length: 53 Bit Score: 103.21 E-value: 1.14e-26

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQENWWFGEVHGGR-GWFPKSYVKI 185
Cdd:cd11837     1 TATALYPWRAKKENHLSFAKGDIITVLEQQEMWWFGELEGGEeGWFPKSYVKE 53

C2 domain;

Pssm-ID: 425499 [Multi-domain] Cd Length: 104 Bit Score: 103.55 E-value: 3.06e-26

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISM--GSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDD 878
Cdd:pfam00168   1 GRLTVTVIEAKNLPPKDGNGTSDPYVKVYLldGKQKKKTKVVKNTLNPVWNETFTFSVPDPENAVLEIEVYDYDRFGRDD 80

                          90
                  ....*....|..
gi 1370477838 879 FLGRTEIPVAKI 890
Cdd:pfam00168  81 FIGEVRIPLSEL 92

Protein kinase C conserved region 2 (CalB); Ca2+-binding motif present in phospholipases, protein kinases C, and synaptotagmins (among others). Some do not appear to contain Ca2+-binding sites. Particular C2s appear to bind phospholipids, inositol polyphosphates, and intracellular proteins. Unusual occurrence in perforin. Synaptotagmin and PLC C2s are permuted in sequence with respect to N- and C-terminal beta strands. SMART detects C2 domains using one or both of two profiles.

Pssm-ID: 214577 [Multi-domain] Cd Length: 101 Bit Score: 99.87 E-value: 6.65e-25

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  802 RLMVHVIEATELKACKPNGKSNPYCEISMG---SQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDD 878
Cdd:smart00239   1 TLTVKIISARNLPPKDKGGKSDPYVKVSLDgdpKEKKKTKVVKNTLNPVWNETFEFEVPPPELAELEIEVYDKDRFGRDD 80

                           90       100
                   ....*....|....*....|
gi 1370477838  879 FLGRTEIPVAKIRTEQESKG 898
Cdd:smart00239  81 FIGQVTIPLSDLLLGGRHEK 100

Second Src homology 3 domain (or SH3B) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212922 [Multi-domain] Cd Length: 52 Bit Score: 92.09 E-value: 9.19e-23

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11989     1 QAQALYPWRAKKDNHLNFNKNDVITVLEQQDMWWFGEVQGQKGWFPKSYVKL 52

Third Src homology 3 domain (or SH3C) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212924 Cd Length: 52 Bit Score: 91.20 E-value: 1.79e-22

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQKDGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11991     1 EYVAMYTYESNEQGDLTFQQGDVILVTKKDGDWWTGTVGDKTGVFPSNYVRP 52

C2 domain first and third repeat in Synaptotagmin-like proteins; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains either the first or third repeat in Synaptotagmin-like proteins with a type-I topology.

Pssm-ID: 176037 [Multi-domain] Cd Length: 121 Bit Score: 90.04 E-value: 2.96e-21

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKAcKPN-------GKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQ 873
Cdd:cd08391     1 GVLRIHVIEAQDLVA-KDKfvgglvkGKSDPYVIVRVGAQTFKSKVIKENLNPKWNEVYEAVVDEVPGQELEIELFDEDP 79

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|.
gi 1370477838 874 fSPDDFLGRTEIPVAKIRTEQESKGPMTrrllLHEVPTGEV 914
Cdd:cd08391    80 -DKDDFLGRLSIDLGSVEKKGFIDEWLP----LEDVKSGRL 115

Src homology 3 domains; Src homology 3 (SH3) domains bind to target proteins through sequences containing proline and hydrophobic amino acids. Pro-containing polypeptides may bind to SH3 domains in 2 different binding orientations.

Pssm-ID: 214620 [Multi-domain] Cd Length: 56 Bit Score: 86.05 E-value: 1.13e-20

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838  360 PVCQVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEIN-GVTGLFPSNYVK 414
Cdd:smart00326   1 EGPQVRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRLGrGKEGLFPSNYVE 56

C2 domain third repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); MCTPs are involved in Ca2+ signaling at the membrane. The cds in this family contain multiple C2 domains as well as a C-terminal PRT domain. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the third C2 repeat, C2C, and has a type-II topology.

Pssm-ID: 176023 [Multi-domain] Cd Length: 119 Bit Score: 87.35 E-value: 2.72e-20

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYqDVLCLTLFDRDQFSPDDFL 880
Cdd:cd08377     1 GFLQVKVIRASGLAAADIGGKSDPFCVLELVNARLQTHTIYKTLNPEWNKIFTFPIKDIH-DVLEVTVYDEDKDKKPEFL 79

                          90
                  ....*....|.
gi 1370477838 881 GRTEIPVAKIR 891
Cdd:cd08377    80 GKVAIPLLSIK 90

C2 domain first repeat present in Synaptotagmin-like proteins; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 175990 [Multi-domain] Cd Length: 128 Bit Score: 86.32 E-value: 6.79e-20

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATEL--KACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDD 878
Cdd:cd04024     1 GVLRVHVVEAKDLaaKDRSGKGKSDPYAILSVGAQRFKTQTIPNTLNPKWNYWCEFPIFSAQNQLLKLILWDKDRFAGKD 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 879 FLGRTEIPVAKIRTEQESKGPMT------RRLLLHEVPTGEVWVRFDL 920
Cdd:cd04024    81 YLGEFDIALEEVFADGKTGQSDKwitlksTRPGKTSVVSGEIHLQFSW 128

Src Homology 3 domain superfamily; Src Homology 3 (SH3) domains are protein interaction domains that bind proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. Thus, they are referred to as proline-recognition domains (PRDs). SH3 domains are less selective and show more diverse specificity compared to other PRDs. They have been shown to bind peptide sequences that lack the PxxP motif; examples include the PxxDY motif of Eps8 and the RKxxYxxY sequence in SKAP55. SH3 domain containing proteins play versatile and diverse roles in the cell, including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies, among others. Many members of this superfamily are adaptor proteins that associate with a number of protein partners, facilitating complex formation and signal transduction.

Pssm-ID: 212690 [Multi-domain] Cd Length: 51 Bit Score: 82.13 E-value: 2.27e-19

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEIN-GVTGLFPSNY 412
Cdd:cd00174     1 YARALYDYEAQDDDELSFKKGDIITVLEKDDDGWWEGELNgGREGLFPANY 51

Src homology 3 domain of Abl Interactor proteins; Abl interactor (Abi) proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. They localize to sites of actin polymerization in epithelial adherens junction and immune synapses, as well as to the leading edge of lamellipodia. Vertebrates contain two Abi proteins, Abi1 and Abi2. Abi1 displays a wide expression pattern while Abi2 is highly expressed in the eye and brain. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212760 [Multi-domain] Cd Length: 52 Bit Score: 81.98 E-value: 2.99e-19

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11826     2 VVALYDYTADKDDELSFQEGDIIYVTKKNDDGWYEGVLNGVTGLFPGNYV 51

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The C-terminal SH3 domains (SH3c) of GRB2 and GRAP2 have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212739 [Multi-domain] Cd Length: 53 Bit Score: 79.98 E-value: 1.30e-18

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11805     1 RVQALYDFNPQEPGELEFRRGDIITVLDSSDPDWWKGELRGRVGIFPANYVQ 52

Src homology 3 domain of Nitric Oxide Synthase TRaffic INducer; Nostrin is expressed in endothelial and epithelial cells and is involved in the regulation, trafficking and targeting of endothelial NOS (eNOS). It facilitates the endocytosis of eNOS by coordinating the functions of dynamin and the Wiskott-Aldrich syndrome protein (WASP). Increased expression of Nostrin may be correlated to preeclampsia. Nostrin contains an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212757 [Multi-domain] Cd Length: 53 Bit Score: 79.31 E-value: 2.27e-18

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11823     4 ALYSYTANREDELSLQPGDIIEVHEKQDDGWWLGELNGKKGIFPATYV 51

C2 domain fourth repeat present in Tricalbin-like proteins; 5 to 6 copies of the C2 domain are present in Tricalbin, a yeast homolog of Synaptotagmin, which is involved in membrane trafficking and sorting. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the fifth C2 repeat, C2E, and has a type-II topology.

Pssm-ID: 176005 [Multi-domain] Cd Length: 115 Bit Score: 78.76 E-value: 2.10e-17

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKACKPNGKSNPYCEISM-GSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDDFLG 881
Cdd:cd04040     1 LTVDVISAENLPSADRNGKSDPFVKFYLnGEKVFKTKTIKKTLNPVWNESFEVPVPSRVRAVLKVEVYDWDRGGKDDLLG 80

                          90
                  ....*....|....
gi 1370477838 882 RTEIPVAKIRTEQE 895
Cdd:cd04040    81 SAYIDLSDLEPEET 94

C2 domain present in Arf GTPase Activating Proteins (GAP); ArfGAP is a GTPase activating protein which regulates the ADP ribosylation factor Arf, a member of the Ras superfamily of GTP-binding proteins. The GTP-bound form of Arf is involved in Golgi morphology and is involved in recruiting coat proteins. ArfGAP is responsible for the GDP-bound form of Arf which is necessary for uncoating the membrane and allowing the Golgi to fuse with an acceptor compartment. These proteins contain an N-terminal ArfGAP domain containing the characteristic zinc finger motif (Cys-x2-Cys-x(16,17)-x2-Cys) and C-terminal C2 domain. C2 domains were first identified in Protein Kinase C (PKC). C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176003 [Multi-domain] Cd Length: 145 Bit Score: 78.91 E-value: 4.41e-17

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 800 IGRLMVHVIEATELKACKPNGkSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLyQDVLCLTLFDRDQFSPDDF 879
Cdd:cd04038     1 LGLLKVRVVRGTNLAVRDFTS-SDPYVVLTLGNQKVKTRVIKKNLNPVWNEELTLSVPNP-MAPLKLEVFDKDTFSKDDS 78

                          90       100       110
                  ....*....|....*....|....*....|
gi 1370477838 880 LGRTEI------PVAKIRTEQESKGPMTRR 903
Cdd:cd04038    79 MGEAEIdleplvEAAKLDHLRDTPGGTQIK 108

First Src homology 3 domain (or SH3A) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN2 is expected to bind many protein partners, similar to ITSN1 which has been shown to bind Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212921 [Multi-domain] Cd Length: 57 Bit Score: 75.29 E-value: 8.59e-17

                          10        20        30
                  ....*....|....*....|....*....|...
gi 1370477838  15 IYSVDEKTVGEPGWLYGSFQGNFGWFPCNYVEK 47
Cdd:cd11988    25 IIQVDEKTVGEPGWLYGSFQGNFGWFPCNYVEK 57

Variant SH3 domain;

Pssm-ID: 434066 [Multi-domain] Cd Length: 49 Bit Score: 74.19 E-value: 1.61e-16

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:pfam14604   1 ALYPYEPKDDDELSLQRGDVITVIEESEDGWWEGINTGRTGLVPANYVE 49

N-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The N-terminal SH3 domain of GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212738 [Multi-domain] Cd Length: 52 Bit Score: 73.54 E-value: 2.56e-16

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKD-DPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11804     3 VAKHDFKATAEDELSFKKGSILKVLNMEdDPNWYKAELDGKEGLIPKNYI 52

Src Homology 3 domain of metazoan osteoclast stimulating factor 1; OSTF1, also named OSF or SH3P2, is a signaling protein containing SH3 and ankyrin-repeat domains. It acts through a Src-related pathway to enhance the formation of osteoclasts and bone resorption. It also acts as a negative regulator of cell motility. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212706 [Multi-domain] Cd Length: 53 Bit Score: 72.72 E-value: 5.66e-16

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11772     4 ALYDYEAQHPDELSFEEGDLLYISDKSDPNWWKATCGGKTGLIPSNYV 51

Src homology 3 domain of Abl Interactor 2; Abi2 is highly expressed in the brain and eye. It regulates actin cytoskeletal reorganization at adherens junctions and dendritic spines, which is important in cell morphogenesis, migration, and cognitive function. Mice deficient with Abi2 show defects in orientation and migration of lens fibers, neuronal migration, dendritic spine morphology, as well as deficits in learning and memory. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212905 [Multi-domain] Cd Length: 61 Bit Score: 72.35 E-value: 8.58e-16

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11972     4 KVVAIYDYTKDKEDELSFQEGAIIYVIKKNDDGWYEGVMNGVTGLFPGNYVE 55

Src Homology 3 domain of Pak Interactive eXchange factors; PIX proteins are Rho guanine nucleotide exchange factors (GEFs), which activate small GTPases by exchanging bound GDP for free GTP. They act as GEFs for both Cdc42 and Rac 1, and have been implicated in cell motility, adhesion, neurite outgrowth, and cell polarity. Vertebrates contain two proteins from the PIX subfamily, alpha-PIX and beta-PIX. Alpha-PIX, also called ARHGEF6, is localized in dendritic spines where it regulates spine morphogenesis. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. Beta-PIX play roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212810 [Multi-domain] Cd Length: 53 Bit Score: 71.96 E-value: 1.12e-15

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11877     1 LVRAKFNFEGTNEDELSFDKGDIITVTQVVEGGWWEGTLNGKTGWFPSNYVK 52

Src homology 3 domains; Src homology 3 (SH3) domains bind to target proteins through sequences containing proline and hydrophobic amino acids. Pro-containing polypeptides may bind to SH3 domains in 2 different binding orientations.

Pssm-ID: 214620 [Multi-domain] Cd Length: 56 Bit Score: 71.80 E-value: 1.37e-15

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838  214 VGEEYIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGD-RSGIFPSNYVK 267
Cdd:smart00326   1 EGPQVRALYDYTAQDPDELSFKKGDIITVLEKsDDGWWKGRLGRgKEGLFPSNYVE 56

Third Src Homology 3 domain (SH3C) of CD2-associated protein and similar proteins; This subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212808 [Multi-domain] Cd Length: 55 Bit Score: 70.84 E-value: 2.32e-15

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD--DPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11875     4 VLFDYEAENEDELTLREGDIVTILSKDceDKGWWKGELNGKRGVFPDNFVE 54

Src Homology 3 domain of SH3 domain-containing protein 21 (SH3D21) and similar proteins; N-terminal SH3 domain of the uncharacterized protein SH3 domain-containing protein 21, and similar uncharacterized domains, it belongs to the CD2AP-like_3 subfamily of proteins. The CD2AP-like_3 subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213018 [Multi-domain] Cd Length: 55 Bit Score: 70.19 E-value: 3.78e-15

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 361 VCQViaMYDYAANNEDELSFSKGQLINVMNKDDPD--WWQGEINGVTGLFPSNYVKM 415
Cdd:cd12142     1 YCRV--LFDYNPVAPDELALKKGDVIEVISKETEDegWWEGELNGRRGFFPDNFVMP 55

C-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domains (SH3c) of the related proteins, GRB2 and GRAP2, have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212884 Cd Length: 53 Bit Score: 70.21 E-value: 3.81e-15

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11951     2 VQAQYDFSAEDPSQLSFRRGDIIEVLDCPDPNWWRGRISGRVGFFPRNYV 51

Src homology 3 domain of Signal Transducing Adaptor Molecule 1; STAM1 is part of the endosomal sorting complex required for transport (ESCRT-0) and is involved in sorting ubiquitinated cargo proteins from the endosome. It may also be involved in the regulation of IL2 and GM-CSF mediated signaling, and has been implicated in neural cell survival. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212897 [Multi-domain] Cd Length: 55 Bit Score: 69.98 E-value: 4.57e-15

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVkmTTD 418
Cdd:cd11964     2 KVRAIYDFEAAEDNELTFKAGDIITILDDSDPNWWKGETPQGTGLFPSNFV--TAD 55

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRB2 binds to Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, as well as to the proline-rich C-terminus of FGRF2. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212882 [Multi-domain] Cd Length: 53 Bit Score: 69.87 E-value: 6.04e-15

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11949     2 VQALFDFDPQEDGELGFRRGDFIEVMDNSDPNWWKGACHGQTGMFPRNYVT 52

Src homology 3 domains; Src homology 3 (SH3) domains bind to target proteins through sequences containing proline and hydrophobic amino acids. Pro-containing polypeptides may bind to SH3 domains in 2 different binding orientations.

Pssm-ID: 214620 [Multi-domain] Cd Length: 56 Bit Score: 69.87 E-value: 6.44e-15

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838  134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGR-GWFPKSYVK 184
Cdd:smart00326   4 QVRALYDYTAQDPDELSFKKGDIITVLEKSDdGWWKGRLGRGKeGLFPSNYVE 56

Src Homology 3 domain of Abelson helper integration site-1 (AHI-1); AHI-1, also called Jouberin, is expressed in high levels in the brain, gonad tissues, and skeletal muscle. It is an adaptor protein that interacts with the small GTPase Rab8a and regulates it distribution and function, affecting cilium formation and vesicle transport. Mutations in the AHI-1 gene can cause Joubert syndrome, a disorder characterized by brainstem malformations, cerebellar aplasia/hypoplasia, and retinal dystrophy. AHI-1 variation is also associated with susceptibility to schizophrenia and type 2 diabetes mellitus progression. AHI-1 contains WD40 and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212746 [Multi-domain] Cd Length: 52 Bit Score: 69.46 E-value: 7.26e-15

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEI-NGVTGLFPSNYV 413
Cdd:cd11812     2 VVALYDYTANRSDELTIHRGDIIRVLYKDNDNWWFGSLvNGQQGYFPANYV 52

Src homology 3 domain of Abl Interactor 1; Abi1, also called e3B1, is a central regulator of actin cytoskeletal reorganization through interactions with many protein complexes. It is part of WAVE, a nucleation-promoting factor complex, that links Rac 1 activation to actin polymerization causing lamellipodia protrusion at the plasma membrane. Abi1 interact with formins to promote protrusions at the leading edge of motile cells. It also is a target of alpha4 integrin, regulating membrane protrusions at sites of integrin engagement. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212904 [Multi-domain] Cd Length: 59 Bit Score: 68.89 E-value: 1.30e-14

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11971     1 KVVAIYDYSKDKDDELSFMEGAIIYVIKKNDDGWYEGVCNGVTGLFPGNYVE 52

SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 394975 [Multi-domain] Cd Length: 47 Bit Score: 68.38 E-value: 1.59e-14

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                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE-INGVTGLFPS 410
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVLEKSEDGWWKGRnKGGKEGLIPS 47

Src homology 3 domain of Signal Transducing Adaptor Molecules; STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. There are two vertebrate STAMs, STAM1 and STAM2, which may be functionally redundant; vertebrate STAMs contain ITAM motifs. They are part of the endosomal sorting complex required for transport (ESCRT-0). STAM2 deficiency in mice did not cause any obvious abnormality, while STAM1 deficiency resulted in growth retardation. Loss of both STAM1 and STAM2 in mice proved lethal, indicating that STAMs are important for embryonic development. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212754 [Multi-domain] Cd Length: 54 Bit Score: 68.26 E-value: 1.79e-14

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11820     2 KVRALYDFEAAEDNELTFKAGEIITVLDDSDPNWWKGSNHRGEGLFPANFVT 53

Third Src Homology 3 domain (SH3C) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CIN85. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212990 [Multi-domain] Cd Length: 56 Bit Score: 68.39 E-value: 1.92e-14

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 362 CQVIamYDYAANNEDELSFSKGQLINVMNKD--DPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd12057     2 CKVL--FPYEAQNEDELTIKEGDIVTLISKDciDAGWWEGELNGRRGVFPDNFVKL 55

First Src Homology 3 domain (SH3A) of CD2-associated protein and similar proteins; This subfamily is composed of the first SH3 domain (SH3A) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3A of both proteins bind to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic domain of the cell adhesion protein CD2. CIN85 SH3A binds to internal proline-rich motifs within the proline-rich region; this intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. CIN85 SH3A has also been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212806 [Multi-domain] Cd Length: 53 Bit Score: 68.06 E-value: 2.46e-14

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11873     2 VIVEFDYDAEEPDELTLKVGDIITNVKKMEEGWWEGTLNGKRGMFPDNFVK 52

Src homology 3 domain of Ysc84p and similar fungal proteins; This family is composed of the Saccharomyces cerevisiae proteins, Ysc84p (also called LAS17-binding protein 4, Lsb4p) and Lsb3p, and similar fungal proteins. They contain an N-terminal SYLF domain (also called DUF500) and a C-terminal SH3 domain. Ysc84p localizes to actin patches and plays an important in actin polymerization during endocytosis. The N-terminal domain of both Ysc84p and Lsb3p can bind and bundle actin filaments. A study of the yeast SH3 domain interactome predicts that the SH3 domains of Lsb3p and Lsb4p may function as molecular hubs for the assembly of endocytic complexes. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212776 [Multi-domain] Cd Length: 55 Bit Score: 68.22 E-value: 2.51e-14

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDG---EWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11842     3 VALYDFAGEQPGDLAFQKGDIITILKKSDsqnDWWTGRIGGREGIFPANYVE 54

Src homology 3 domain of Ysc84p and similar fungal proteins; This family is composed of the Saccharomyces cerevisiae proteins, Ysc84p (also called LAS17-binding protein 4, Lsb4p) and Lsb3p, and similar fungal proteins. They contain an N-terminal SYLF domain (also called DUF500) and a C-terminal SH3 domain. Ysc84p localizes to actin patches and plays an important in actin polymerization during endocytosis. The N-terminal domain of both Ysc84p and Lsb3p can bind and bundle actin filaments. A study of the yeast SH3 domain interactome predicts that the SH3 domains of Lsb3p and Lsb4p may function as molecular hubs for the assembly of endocytic complexes. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212776 [Multi-domain] Cd Length: 55 Bit Score: 67.83 E-value: 2.66e-14

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDP--DWWQGEINGVTGLFPSNYVK 414
Cdd:cd11842     1 KAVALYDFAGEQPGDLAFQKGDIITILKKSDSqnDWWTGRIGGREGIFPANYVE 54

Src Homology 3 domain superfamily; Src Homology 3 (SH3) domains are protein interaction domains that bind proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. Thus, they are referred to as proline-recognition domains (PRDs). SH3 domains are less selective and show more diverse specificity compared to other PRDs. They have been shown to bind peptide sequences that lack the PxxP motif; examples include the PxxDY motif of Eps8 and the RKxxYxxY sequence in SKAP55. SH3 domain containing proteins play versatile and diverse roles in the cell, including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies, among others. Many members of this superfamily are adaptor proteins that associate with a number of protein partners, facilitating complex formation and signal transduction.

Pssm-ID: 212690 [Multi-domain] Cd Length: 51 Bit Score: 67.49 E-value: 3.14e-14

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGD-RSGIFPSNY 265
Cdd:cd00174     2 ARALYDYEAQDDDELSFKKGDIITVLEKdDDGWWEGELNGgREGLFPANY 51

Src homology 3 domain of Myosins Ie, If, and similar proteins; Myosins Ie (MyoIe) and If (MyoIf) are nonmuscle, unconventional, long tailed, class I myosins containing an N-terminal motor domain and a myosin tail with TH1, TH2, and SH3 domains. MyoIe interacts with the endocytic proteins, dynamin and synaptojanin-1, through its SH3 domain; it may play a role in clathrin-dependent endocytosis. In the kidney, MyoIe is critical for podocyte function and normal glomerular filtration. Mutations in MyoIe is associated with focal segmental glomerulosclerosis, a disease characterized by massive proteinuria and progression to end-stage kidney disease. MyoIf is predominantly expressed in the immune system; it plays a role in immune cell motility and innate immunity. Mutations in MyoIf may be associated with the loss of hearing. The MyoIf gene has also been found to be fused to the MLL (Mixed lineage leukemia) gene in infant acute myeloid leukemias (AML). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212761 [Multi-domain] Cd Length: 53 Bit Score: 67.44 E-value: 4.18e-14

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11827     1 QCKALYAYDAQDTDELSFNEGDIIEILKEDPSGWWTGRLRGKEGLFPGNYV 51

Second Src Homology 3 domain of Nck adaptor proteins; Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212700 [Multi-domain] Cd Length: 53 Bit Score: 67.29 E-value: 4.29e-14

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11766     1 PAVVKFNYEAQREDELSLRKGDRVLVLEKSSDGWWRGECNGQVGWFPSNYV 51

Src homology 3 domain of Endophilin-A; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain three endophilin-A isoforms (A1, A2, and A3). Endophilin-A proteins are enriched in the brain and play multiple roles in receptor-mediated endocytosis. They tubulate membranes and regulate calcium influx into neurons to trigger the activation of the endocytic machinery. They are also involved in the sorting of plasma membrane proteins, actin filament assembly, and the uncoating of clathrin-coated vesicles for fusion with endosomes. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212737 [Multi-domain] Cd Length: 55 Bit Score: 67.28 E-value: 4.95e-14

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 360 PVCQviAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11803     1 PCCR--ALYDFEPENEGELGFKEGDIITLTNQIDENWYEGMVNGQSGFFPVNYV 52

Src Homology 3 domain of beta-Pak Interactive eXchange factor; Beta-PIX, also called Rho guanine nucleotide exchange factor 7 (ARHGEF7) or Cool (Cloned out of Library)-1, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212994 [Multi-domain] Cd Length: 54 Bit Score: 67.02 E-value: 5.03e-14

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12061     2 VRAKFNFQQTNEDELSFSKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVR 52

Second Src Homology 3 domain (SH3B) of CD2-associated protein and similar proteins; This subfamily is composed of the second SH3 domain (SH3B) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3B of both proteins have been shown to bind to Cbl. In the case of CD2AP, its SH3B binds to Cbl at a site distinct from the c-Cbl/SH3A binding site. The CIN85 SH3B also binds ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212807 [Multi-domain] Cd Length: 53 Bit Score: 66.97 E-value: 5.48e-14

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 362 CQVIamYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11874     2 CKVL--FSYTPQNEDELELKVGDTIEVLGEVEEGWWEGKLNGKVGVFPSNFVKE 53

C-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also has roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRAP2 binds to different motifs found in substrate peptides including the typical PxxP motif in hematopoietic progenitor kinase 1 (HPK1), the RxxK motif in SLP-76 and HPK1, and the RxxxxK motif in phosphatase-like protein HD-PTP. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212883 [Multi-domain] Cd Length: 53 Bit Score: 66.77 E-value: 6.28e-14

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11950     1 QVRALYDFEALEDDELGFNSGDVIEVLDSSNPSWWKGRLHGKLGLFPANYVA 52

Second Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212696 [Multi-domain] Cd Length: 57 Bit Score: 66.65 E-value: 9.19e-14

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPD----WWQGEINGVTGLFPS 410
Cdd:cd11762     4 ALYDYEAQSDEELSFPEGAIIRILRKDDNGvddgWWEGEFNGRVGVFPS 52

Src homology 3 domain of Cortactin; Cortactin was originally identified as a substrate of Src kinase. It is an actin regulatory protein that binds to the Arp2/3 complex and stabilizes branched actin filaments. It is involved in cellular processes that affect cell motility, adhesion, migration, endocytosis, and invasion. It is expressed ubiquitously except in hematopoietic cells, where the homolog hematopoietic lineage cell-specific 1 (HS1) is expressed instead. Cortactin contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region interacts with the Arp2/3 complex and F-actin, and is crucial in regulating branched actin assembly. Cortactin also serves as a scaffold and provides a bridge to the actin cytoskeleton for membrane trafficking and signaling proteins that bind to its SH3 domain. Binding partners for the SH3 domain of cortactin include dynamin2, N-WASp, MIM, FGD1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212892 [Multi-domain] Cd Length: 53 Bit Score: 66.29 E-value: 9.85e-14

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11959     3 VALYDYQAADDDEISFDPDDIITNIEMIDEGWWRGVCRGKYGLFPANYVEL 53

Src Homology 3 domain superfamily; Src Homology 3 (SH3) domains are protein interaction domains that bind proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. Thus, they are referred to as proline-recognition domains (PRDs). SH3 domains are less selective and show more diverse specificity compared to other PRDs. They have been shown to bind peptide sequences that lack the PxxP motif; examples include the PxxDY motif of Eps8 and the RKxxYxxY sequence in SKAP55. SH3 domain containing proteins play versatile and diverse roles in the cell, including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies, among others. Many members of this superfamily are adaptor proteins that associate with a number of protein partners, facilitating complex formation and signal transduction.

Pssm-ID: 212690 [Multi-domain] Cd Length: 51 Bit Score: 65.95 E-value: 1.26e-13

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQ-ENWWFGEVHGGR-GWFPKSY 182
Cdd:cd00174     1 YARALYDYEAQDDDELSFKKGDIITVLEKDdDGWWEGELNGGReGLFPANY 51

C2 domain second repeat present in RasA1 and RasA4; RasA1 and RasA4 are GAP1s (GTPase activating protein 1s ), Ras-specific GAP members, which suppresses Ras function by enhancing the GTPase activity of Ras proteins resulting in the inactive GDP-bound form of Ras. In this way it can control cellular proliferation and differentiation. Both proteins contain two C2 domains, a Ras-GAP domain, a plextrin homology (PH)-like domain, and a Bruton's Tyrosine Kinase (BTK) zinc binding domain. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 175991 [Multi-domain] Cd Length: 123 Bit Score: 68.28 E-value: 1.49e-13

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 802 RLMVHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDDFLG 881
Cdd:cd04025     1 RLRCHVLEARDLAPKDRNGTSDPFVRVFYNGQTLETSVVKKSCYPRWNEVFEFELMEGADSPLSVEVWDWDLVSKNDFLG 80

                          90
                  ....*....|....*..
gi 1370477838 882 RTEIPVAKIRTEQESKG 898
Cdd:cd04025    81 KVVFSIQTLQQAKQEEG 97

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase and similar proteins; This subfamily is composed of Rho GTPase activating proteins (GAPs) with similarity to GRAF. Members contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. Although vertebrates harbor four Rho GAPs in the GRAF subfamily including GRAF, GRAF2, GRAF3, and Oligophrenin-1 (OPHN1), only three are included in this model. OPHN1 contains the BAR, PH and GAP domains, but not the C-terminal SH3 domain. GRAF and GRAF2 show GAP activity towards RhoA and Cdc42. GRAF influences Rho-mediated cytoskeletal rearrangements and binds focal adhesion kinase. GRAF2 regulates caspase-activated p21-activated protein kinase-2. The SH3 domain of GRAF and GRAF2 binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212815 [Multi-domain] Cd Length: 54 Bit Score: 65.78 E-value: 1.58e-13

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLI-NVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11882     1 RARALYACKAEDESELSFEPGQIItNVQPSDEPGWLEGTLNGRTGLIPENYVE 53

Src homology 3 domain of Signal Transducing Adaptor Molecule 2; STAM2, also called EAST (Epidermal growth factor receptor-associated protein with SH3 and TAM domain) or Hbp (Hrs binding protein), is part of the endosomal sorting complex required for transport (ESCRT-0). It plays a role in sorting mono-ubiquinated endosomal cargo for trafficking to the lysosome for degradation. It is also involved in the regulation of exocytosis. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212896 [Multi-domain] Cd Length: 57 Bit Score: 65.81 E-value: 1.58e-13

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVkmTTD 418
Cdd:cd11963     3 KVRALYDFEAVEDNELTFKHGEIIIVLDDSDANWWKGENHRGVGLFPSNFV--TTD 56

Src homology 3 domain of Slit-Robo GTPase Activating Protein 4; srGAP4, also called ARHGAP4, is highly expressed in hematopoietic cells and may play a role in lymphocyte differentiation. It is able to stimulate the GTPase activity of Rac1, Cdc42, and RhoA. In the nervous system, srGAP4 has been detected in differentiating neurites and may be involved in axon and dendritic growth. srGAPs are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212889 [Multi-domain] Cd Length: 55 Bit Score: 65.63 E-value: 1.69e-13

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 361 VCQVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11956     1 EVEAVACFDYTGRTAQELSFKRGDVLLLHSKASSDWWRGEHNGMRGLIPHKYI 53

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The C-terminal SH3 domains (SH3c) of GRB2 and GRAP2 have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212739 [Multi-domain] Cd Length: 53 Bit Score: 65.73 E-value: 1.76e-13

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gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11805     4 ALYDFNPQEPGELEFRRGDIITVLDSsDPDWWKGELRGRVGIFPANYVQP 53

Variant SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 429575 [Multi-domain] Cd Length: 54 Bit Score: 65.31 E-value: 1.88e-13

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gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKII 186
Cdd:pfam07653   1 YGRVIFDYVGTDKNGLTLKKGDVVKVLGKdNDGWWEGETGGRVGLVPSTAVEEI 54

First Src Homology 3 domain (SH3A) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CIN85; SH3A binds to internal proline-rich motifs within the proline-rich region. This intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. SH3A has also been shown to bind ubiquitin and to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic end of the cell adhesion protein CD2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212985 [Multi-domain] Cd Length: 53 Bit Score: 65.30 E-value: 1.95e-13

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gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12052     1 EAIVEFDYKAQHEDELTITVGDIITKIKKDDGGWWEGEIKGRRGLFPDNFVR 52

Third Src homology 3 domain (or SH3C) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. The SH3C of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212772 [Multi-domain] Cd Length: 52 Bit Score: 65.13 E-value: 2.34e-13

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gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVmNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11838     3 IALYPYESNEPGDLTFNAGDVILV-TKKDGEWWTGTIGDRTGIFPSNYVR 51

Src homology 3 domain of Proline-Serine-Threonine Phosphatase-Interacting Protein 1; PSTPIP1, also called CD2 Binding Protein 1 (CD2BP1), is mainly expressed in hematopoietic cells. It is a binding partner of the cell surface receptor CD2 and PTP-PEST, a tyrosine phosphatase which functions in cell motility and Rac1 regulation. It also plays a role in the activation of the Wiskott-Aldrich syndrome protein (WASP), which couples actin rearrangement and T cell activation. Mutations in the gene encoding PSTPIP1 cause the autoinflammatory disorder known as PAPA (pyogenic sterile arthritis, pyoderma gangrenosum, and acne) syndrome. PSTPIP1 contains an N-terminal F-BAR domain, PEST motifs, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212758 [Multi-domain] Cd Length: 53 Bit Score: 65.09 E-value: 2.49e-13

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11824     3 SVLYDYTAQEDDELSISKGDVVAVIEKGEDGWWTVERNGQKGLVPGTYLE 52

Second C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212894 [Multi-domain] Cd Length: 53 Bit Score: 65.24 E-value: 2.58e-13

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gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11961     2 AKALYDYDAAEDNELSFFENDKIINIEFVDDDWWLGECHGSRGLFPSNYVEL 53

Variant SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 429575 [Multi-domain] Cd Length: 54 Bit Score: 64.92 E-value: 2.62e-13

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:pfam07653   2 GRVIFDYVGTDKNGLTLKKGDVVKVLGKDNDGWWEGETGGRVGLVPSTAVE 52

Src homology 3 domain of Phospholipase C (PLC) gamma; PLC catalyzes the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG) in response to various receptors. Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma catalyzes this reaction in tyrosine kinase-dependent signaling pathways. It is activated and recruited to its substrate at the membrane. Vertebrates contain two forms of PLCgamma, PLCgamma1, which is widely expressed, and PLCgamma2, which is primarily found in haematopoietic cells. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212759 [Multi-domain] Cd Length: 54 Bit Score: 64.66 E-value: 3.29e-13

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gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEING-VTGLFPSNYVK 414
Cdd:cd11825     2 VKALYDYRAQRPDELSFCKHAIITNVEKEDGGWWRGDYGGkKQKWFPANYVE 53

Src Homology 3 domain of metazoan osteoclast stimulating factor 1; OSTF1, also named OSF or SH3P2, is a signaling protein containing SH3 and ankyrin-repeat domains. It acts through a Src-related pathway to enhance the formation of osteoclasts and bone resorption. It also acts as a negative regulator of cell motility. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212706 [Multi-domain] Cd Length: 53 Bit Score: 64.63 E-value: 3.52e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVT-QKDGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11772     2 FRALYDYEAQHPDELSFEEGDLLYISdKSDPNWWKATCGGKTGLIPSNYVEE 53

First Src homology 3 domain (or SH3A) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212770 [Multi-domain] Cd Length: 55 Bit Score: 64.69 E-value: 3.73e-13

                          10        20        30
                  ....*....|....*....|....*....|...
gi 1370477838  15 IYSVDEKTVGEPGWLYGSFQGNFGWFPCNYVEK 47
Cdd:cd11836    23 IIQVDESQVAEPGWLAGELKGKTGWFPANYVEK 55

Src Homology 3 domain of Mixed Lineage Kinases 1, 2, and 3; MLKs 1, 2, and 3 are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Little is known about the specific function of MLK1, also called MAP3K9. It is capable of activating the c-Jun N-terminal kinase pathway. Mice lacking both MLK1 and MLK2 are viable, fertile, and have normal life spans. MLK2, also called MAP3K10, is abundant in brain, skeletal muscle, and testis. It functions upstream of the MAPK, c-Jun N-terminal kinase. It binds hippocalcin, a calcium-sensor protein that protects neurons against calcium-induced cell death. Both MLK2 and hippocalcin may be associated with the pathogenesis of Parkinson's disease. MLK3, also called MAP3K11, is highly expressed in breast cancer cells and its signaling through c-Jun N-terminal kinase has been implicated in the migration, invasion, and malignancy of cancer cells. It also functions as a negative regulator of Inhibitor of Nuclear Factor-KappaB Kinase (IKK) and thus, impacts inflammation and immunity. MLKs contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212992 [Multi-domain] Cd Length: 58 Bit Score: 64.40 E-value: 4.80e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD-----DPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd12059     4 AVFDYEASAEDELTLRRGDRVEVLSKDsavsgDEGWWTGKINDRVGIFPSNYVTS 58

Src homology 3 domain of SH3 domain containing Ysc84-like 1 (SH3YL1) protein; SH3YL1 localizes to the plasma membrane and is required for dorsal ruffle formation. It binds phosphoinositides (PIs) with high affinity through its N-terminal SYLF domain (also called DUF500). In addition, SH3YL1 contains a C-terminal SH3 domain which has been reported to bind to N-WASP, dynamin 2, and SHIP2 (a PI 5-phosphatase). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212775 Cd Length: 54 Bit Score: 64.34 E-value: 5.05e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILV---TQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11841     4 ALYSFEGQQPCDLSFQAGDRITVltrTDSQFDWWEGRLRGRVGIFPANYVS 54

C2 domain first repeat; fungal group; C2 domains were first identified in Protein Kinase C (PKC). C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176006 [Multi-domain] Cd Length: 111 Bit Score: 66.13 E-value: 5.39e-13

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPN-GKSNPYCEISM---GSQSYTTRTIQDTLNPKWNfnCQFFIKDLYQDV-----LCLTLFDR 871
Cdd:cd04041     1 GVLVVTIHRATDLPKADFGtGSSDPYVTASFakfGKPLYSTRIIRKDLNPVWE--ETWFVLVTPDEVkagerLSCRLWDS 78

                          90       100       110
                  ....*....|....*....|....*....|...
gi 1370477838 872 DQFSPDDFLGRTEIPVAKIrteQESKGPMTRRL 904
Cdd:cd04041    79 DRFTADDRLGRVEIDLKEL---IEDRNWMGRRE 108

Src Homology 3 domain of Mixed Lineage Kinases; MLKs are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Mammals have four MLKs (MLK1-4), mostly conserved in vertebrates, which contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212809 [Multi-domain] Cd Length: 58 Bit Score: 64.07 E-value: 6.14e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD-----DPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11876     4 ALFDYDARGEDELTLRRGQPVEVLSKDaavsgDEGWWTGKIGDKVGIFPSNYV 56

Src homology 3 domain of Cortactin and related proteins; This subfamily includes cortactin, Abp1 (actin-binding protein 1), hematopoietic lineage cell-specific protein 1 (HS1), and similar proteins. These proteins are involved in regulating actin dynamics through direct or indirect interaction with the Arp2/3 complex, which is required to initiate actin polymerization. They all contain at least one C-terminal SH3 domain. Cortactin and HS1 bind Arp2/3 and actin through an N-terminal region that contains an acidic domain and several copies of a repeat domain found in cortactin and HS1. Abp1 binds actin via an N-terminal actin-depolymerizing factor (ADF) homology domain. Yeast Abp1 binds Arp2/3 directly through two acidic domains. Mammalian Abp1 does not directly interact with Arp2/3; instead, it regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. The C-terminal region of these proteins acts as an adaptor or scaffold that can connect membrane trafficking and signaling proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212753 [Multi-domain] Cd Length: 54 Bit Score: 63.87 E-value: 6.18e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEIN-GVTGLFPSNYVKM 415
Cdd:cd11819     3 KALYDYQAAEDNEISFVEGDIITQIEQIDEGWWLGVNAkGQKGLFPANYVEL 54

Src Homology 3 domain of Mixed Lineage Kinase 4; MLK4 is a Serine/Threonine Kinase (STK), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. The specific function of MLK4 is yet to be determined. Mutations in the kinase domain of MLK4 have been detected in colorectal cancers. MLK4 contains an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212991 [Multi-domain] Cd Length: 58 Bit Score: 64.19 E-value: 6.73e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD-----DPDWWQGEINGVTGLFPSNYV 413
Cdd:cd12058     4 ALYDYEASGEDELSLRRGDVVEVLSQDaavsgDDGWWAGKIRHRLGIFPANYV 56

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing proteins; ASAPs are Arf GTPase activating proteins (GAPs) and they function in regulating cell growth, migration, and invasion. They contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. Vertebrates contain at least three members, ASAP1, ASAP2, and ASAP3, but some ASAP3 proteins do not seem to harbor a C-terminal SH3 domain. ASAP1 and ASAP2 show GTPase activating protein (GAP) activity towards Arf1 and Arf5. They do not show GAP activity towards Arf6, but are able to mediate Arf6 signaling by binding stably to GTP-Arf6. ASAP3 is an Arf6-specific GAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212755 [Multi-domain] Cd Length: 53 Bit Score: 63.87 E-value: 6.96e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEING---VTGLFPSNY 412
Cdd:cd11821     2 VRALYDCQADNDDELTFSEGEIIVVTGEEDDEWWEGHIEGdpsRRGVFPVSF 53

N-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. Its N-terminal SH3 domain binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212879 [Multi-domain] Cd Length: 56 Bit Score: 63.51 E-value: 1.22e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKD-DPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11946     2 EAIAKYDFKATADDELSFKRGDILKVLNEEcDQNWYKAELNGKDGFIPKNYIEM 55

Src Homology 3 domain of alpha-Pak Interactive eXchange factor; Alpha-PIX, also called Rho guanine nucleotide exchange factor 6 (ARHGEF6) or Cool (Cloned out of Library)-2, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and is localized in dendritic spines where it regulates spine morphogenesis. It controls dendritic length and spine density in the hippocampus. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212993 Cd Length: 58 Bit Score: 63.48 E-value: 1.23e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12060     4 VKARFNFKQTNEDELSVCKGDIIYVTRVEEGGWWEGTLNGKTGWFPSNYVR 54

Src homology 3 domain of Src kinase-like Protein Tyrosine Kinases; Src subfamily members include Src, Lck, Hck, Blk, Lyn, Fgr, Fyn, Yrk, Yes, and Brk. Src (or c-Src) proteins are cytoplasmic (or non-receptor) PTKs which are anchored to the plasma membrane. They contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Brk lacks the N-terminal myristoylation sites. Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. They were identified as the first proto-oncogene products, and they regulate cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Src kinases are overexpressed in a variety of human cancers, making them attractive targets for therapy. They are also implicated in acute inflammatory responses and osteoclast function. Src, Fyn, Yes, and Yrk are widely expressed, while Blk, Lck, Hck, Fgr, Lyn, and Brk show a limited expression pattern. This subfamily also includes Drosophila Src42A, Src oncogene at 42A (also known as Dsrc41) which accumulates at sites of cell-cell or cell-matrix adhesion, and participates in Drosphila development and wound healing. It has been shown to promote tube elongation in the tracheal system, is essential for proper cell-cell matching during dorsal closure, and regulates cell-cell contacts in developing Drosophila eyes. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212779 [Multi-domain] Cd Length: 52 Bit Score: 62.60 E-value: 1.86e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE--INGVTGLFPSNY 412
Cdd:cd11845     1 IYVALYDYEARTDDDLSFKKGDRLQILDDSDGDWWLARhlSTGKEGYIPSNY 52

Src homology 3 domain of Protein arginine N-methyltransferase 2; PRMT2, also called HRMT1L1, belongs to the arginine methyltransferase protein family. It functions as a coactivator to both estrogen receptor alpha (ER-alpha) and androgen receptor (AR), presumably through arginine methylation. The ER-alpha transcription factor is involved in cell proliferation, differentiation, morphogenesis, and apoptosis, and is also implicated in the development and progression of breast cancer. PRMT2 and its variants are upregulated in breast cancer cells and may be involved in modulating the ER-alpha signaling pathway during formation of breast cancer. PRMT2 also plays a role in regulating the function of E2F transcription factors, which are critical cell cycle regulators, by binding to the retinoblastoma gene product (RB). It contains an N-terminal SH3 domain and an AdoMet binding domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212740 [Multi-domain] Cd Length: 53 Bit Score: 62.41 E-value: 2.01e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11806     2 YVAIADFVATDDSQLSFESGDKLLVLRKPSVDWWWAEHNGCCGYIPASHL 51

Third Src homology 3 domain (or SH3C) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212924 Cd Length: 52 Bit Score: 62.69 E-value: 2.10e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDpDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11991     1 EYVAMYTYESNEQGDLTFQQGDVILVTKKDG-DWWTGTVGDKTGVFPSNYVRP 52

Second Src Homology 3 domain of Bzz1 and similar domains; Bzz1 (or Bzz1p) is a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Together with other proteins, it induces membrane scission in yeast. Bzz1 contains an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a central coiled-coil, and two C-terminal SH3 domains. This model represents the second C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212712 [Multi-domain] Cd Length: 51 Bit Score: 62.52 E-value: 2.14e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPD-WWQGEINGVTGLFPSNY 412
Cdd:cd11778     2 VEALYDYEAQGDDEISIRVGDRIAVIRGDDGSgWTYGEINGVKGLFPTSY 51

C2 domain present in the Human neural precursor cell-expressed, developmentally down-regulated 4 (NEDD4) and NEDD4-like (NEDD4L/NEDD42); Nedd4 and Nedd4-2 are two of the nine members of the Human Nedd4 family. All vertebrates appear to have both Nedd4 and Nedd4-2 genes. They are thought to participate in the regulation of epithelial Na+ channel (ENaC) activity. They also have identical specificity for ubiquitin conjugating enzymes (E2). Nedd4 and Nedd4-2 are composed of a C2 domain, 2-4 WW domains, and a ubiquitin ligase Hect domain. Their WW domains can bind PPxY (PY) or LPSY motifs, and in vitro studies suggest that WW3 and WW4 of both proteins bind PY motifs in the key substrates, with WW3 generally exhibiting higher affinity. Most Nedd4 family members, especially Nedd4-2, also have multiple splice variants, which might play different roles in regulating their substrates. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 175999 [Multi-domain] Cd Length: 133 Bit Score: 65.07 E-value: 2.16e-12

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKACKPNGKSNPYCEISM-------GSQSYTTRTIQDTLNPKWnfNCQFFIK-DLYQDVLCLTLFDRDQF 874
Cdd:cd04033     2 LRVKVLAGIDLAKKDIFGASDPYVKISLydpdgngEIDSVQTKTIKKTLNPKW--NEEFFFRvNPREHRLLFEVFDENRL 79

                          90       100       110
                  ....*....|....*....|....*....|....*
gi 1370477838 875 SPDDFLGRTEIPVAKIRTEQE--SKGPMTRRLLLH 907
Cdd:cd04033    80 TRDDFLGQVEVPLNNLPTETPgnERRYTFKDYLLR 114

Third Src Homology 3 domain of Nck adaptor proteins; This group contains the third SH3 domain of Nck, the first SH3 domain of Caenorhabditis elegans Ced-2 (Cell death abnormality protein 2), and similar domains. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. Ced-2 is a cell corpse engulfment protein that interacts with Ced-5 in a pathway that regulates the activation of Ced-10, a Rac small GTPase.

Pssm-ID: 212701 [Multi-domain] Cd Length: 56 Bit Score: 62.33 E-value: 2.53e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNK--DDPDWWQGE-INGVTGLFPSNYVK 414
Cdd:cd11767     2 VVALYPFTGENDEELSFEKGERLEIIEKpeDDPDWWKARnALGTTGLVPRNYVE 55

Fourth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212751 [Multi-domain] Cd Length: 50 Bit Score: 61.73 E-value: 3.59e-12

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNY 412
Cdd:cd11817     2 AVALYDFTGETEEDLSFQRGDRILVTEHLDAEWSRGRLNGREGIFPRAF 50

C2 domain first repeat present in Tricalbin-like proteins; 5 to 6 copies of the C2 domain are present in Tricalbin, a yeast homolog of Synaptotagmin, which is involved in membrane trafficking and sorting. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-II topology.

Pssm-ID: 176009 [Multi-domain] Cd Length: 124 Bit Score: 63.73 E-value: 5.57e-12

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 800 IGRLMVHVIEATELKAC-KPNGKSNPYCEISMGSQSYT--TRTIQDTLNPKWNfNCQFFIKDLYQDVLCLTLFDRDQFSP 876
Cdd:cd04044     1 IGVLAVTIKSARGLKGSdIIGGTVDPYVTFSISNRRELarTKVKKDTSNPVWN-ETKYILVNSLTEPLNLTVYDFNDKRK 79

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 877 DDFLGRTEIPVAKIRTEQESKGpMTRRLLLHEVPTGEvwVRFDLQLF 923
Cdd:cd04044    80 DKLIGTAEFDLSSLLQNPEQEN-LTKNLLRNGKPVGE--LNYDLRFF 123

C2 domain second repeat present in Synaptotagmin-like proteins 1-4; All Slp members basically share an N-terminal Slp homology domain (SHD) and C-terminal tandem C2 domains (named the C2A domain and the C2B domain) with the SHD and C2 domains being separated by a linker sequence of various length. Slp1/JFC1 and Slp2/exophilin 4 promote granule docking to the plasma membrane. Additionally, their C2A domains are both Ca2+ independent, unlike the case in Slp3 and Slp4/granuphilin in which their C2A domains are Ca2+ dependent. It is thought that SHD (except for the Slp4-SHD) functions as a specific Rab27A/B-binding domain. In addition to Slps, rabphilin, Noc2, and Munc13-4 also function as Rab27-binding proteins. It has been demonstrated that Slp3 and Slp4/granuphilin promote dense-core vesicle exocytosis. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 175987 [Multi-domain] Cd Length: 162 Bit Score: 64.65 E-value: 5.86e-12

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 777 QYIDTEKkkrekaYQARSQKTSGIGRLMVHVIEATELKACKPNGKSNPYCEISM--GSQSYT---TRTIQDTLNPKWN-- 849
Cdd:cd04020     9 KYVPPES------EGALKSKKPSTGELHVWVKEAKNLPALKSGGTSDSFVKCYLlpDKSKKSkqkTPVVKKSVNPVWNht 82

                          90       100       110
                  ....*....|....*....|....*....|....
gi 1370477838 850 --FNcQFFIKDLYQDVLCLTLFDRDQFSPDDFLG 881
Cdd:cd04020    83 fvYD-GVSPEDLSQACLELTVWDHDKLSSNDFLG 115

Fifth Src homology 3 domain (or SH3E) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212774 [Multi-domain] Cd Length: 53 Bit Score: 61.28 E-value: 5.91e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKD-GEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11840     3 IALFPYTAQNEDELSFQKGDIINVLSKDdPDWWRGELNGQTGLFPSNYVEP 53

Src homology 3 domain of Hematopoietic lineage cell-specific protein 1; HS1, also called HCLS1 (hematopoietic cell-specific Lyn substrate 1), is a cortactin homolog expressed specifically in hematopoietic cells. It is an actin regulatory protein that binds the Arp2/3 complex and stabilizes branched actin filaments. It is required for cell spreading and signaling in lymphocytes. It regulates cytoskeletal remodeling that controls lymphocyte trafficking, and it also affects tissue invasion and infiltration of leukemic B cells. Like cortactin, HS1 contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region binds the Arp2/3 complex and F-actin, while the C-terminal region acts as an adaptor or scaffold that can connect varied proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213006 [Multi-domain] Cd Length: 55 Bit Score: 61.00 E-value: 7.88e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 361 VCQViAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKMT 416
Cdd:cd12073     1 ICAV-ALYDYQGEGDDEISFDPQETITDIEMVDEGWWKGTCHGHRGLFPANYVELL 55

C2 domain first repeat in Munc13 (mammalian uncoordinated)-like proteins; C2-like domains are thought to be involved in phospholipid binding in a Ca2+ independent manner in both Unc13 and Munc13. Caenorabditis elegans Unc13 has a central domain with sequence similarity to PKC, which includes C1 and C2-related domains. Unc13 binds phorbol esters and DAG with high affinity in a phospholipid manner. Mutations in Unc13 results in abnormal neuronal connections and impairment in cholinergic neurotransmission in the nematode. Munc13 is the mammalian homolog which are expressed in the brain. There are 3 isoforms (Munc13-1, -2, -3) and are thought to play a role in neurotransmitter release and are hypothesized to be high-affinity receptors for phorbol esters. Unc13 and Munc13 contain both C1 and C2 domains. There are two C2 related domains present, one central and one at the carboxyl end. Munc13-1 contains a third C2-like domain. Munc13 interacts with syntaxin, synaptobrevin, and synaptotagmin suggesting a role for these as scaffolding proteins. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

Pssm-ID: 176058 [Multi-domain] Cd Length: 153 Bit Score: 63.93 E-value: 8.07e-12

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 787 EKAYQARSQKTSGIGRLMVHVIEATELKACKPNGKSNPYCEIS----------------MGSQS-------------YTT 837
Cdd:cd08676    14 EALLERVREAEPPIFVLKVTVIEAKGLLAKDVNGFSDPYCMLGivpasrernsekskkrKSHRKkavlkdtvpaksiKVT 93

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1370477838 838 RTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDqfspDDFLGRTEIPVAKIRTEQES 896
Cdd:cd08676    94 EVKPQTLNPVWNETFRFEVEDVSNDQLHLDIWDHD----DDFLGCVNIPLKDLPSCGLD 148

Third Src Homology 3 domain (SH3C) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CD2AP. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212989 [Multi-domain] Cd Length: 57 Bit Score: 60.61 E-value: 1.01e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD--DPDWWQGEINGVTGLFPSNYV 413
Cdd:cd12056     6 ALFHYEGTNEDELDFKEGEIILIISKDtgEPGWWKGELNGKEGVFPDNFV 55

Src homology 3 domain of Slit-Robo GTPase Activating Proteins; Slit-Robo GTPase Activating Proteins (srGAPs) are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. Vertebrates contain three isoforms of srGAPs (srGAP1-3), all of which are expressed during embryonic and early development in the nervous system but with different localization and timing. A fourth member has also been reported (srGAP4, also called ARHGAP4). srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212743 [Multi-domain] Cd Length: 53 Bit Score: 60.49 E-value: 1.02e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11809     3 TAQFDYTGRSERELSFKKGDSLTLYRQVSDDWWRGQLNGQDGLVPHKYI 51

RhoGEF, Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases [Signal transduction mechanisms];

Pssm-ID: 227709 [Multi-domain] Cd Length: 1175 Bit Score: 69.15 E-value: 1.08e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  439 ERKRQGYIHELIQTEERYMADLQLVVEVFQKRMAESGFLTEGE----MALIFVNWKELIMSNTKLLKALRVRKKTggeKM 514
Cdd:COG5422    482 EIKRQEAIYEVIYTERDFVKDLEYLRDTWIKPLEESNIIPENArrnfIKHVFANINEIYAVNSKLLKALTNRQCL---SP 558

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  515 PVQMIGDILAAELSHMQAYIRFCSCQLNGAALLQQKTDEDTDFKEF--LKKLASDPRCKGmpLSSFLLKPMQRITRYPLL 592
Cdd:COG5422    559 IVNGIADIFLDYVPKFEPFIKYGASQPYAKYEFEREKSVNPNFARFdhEVERLDESRKLE--LDGYLTKPTTRLARYPLL 636

                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  593 IRSILENTPESHADHSSLKLALERAEELCSQVNEGVREKENsdRLEWIQahvqcegLAEQLIFNSLTNCLG----PRKLL 668
Cdd:COG5422    637 LEEVLKFTDPDNPDTEDIPKVIDMLREFLSRLNFESGKAEN--RGDLFH-------LNQQLLFKPEYVNLGlndeYRKII 707

                          250       260       270
                   ....*....|....*....|....*....|..
gi 1370477838  669 HSGKLYKTKSNK-------ELHGFLFNDFLLL 693
Cdd:COG5422    708 FKGVLKRKAKSKtdgslrgDIQFFLLDNMLLF 739

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212777 [Multi-domain] Cd Length: 53 Bit Score: 60.51 E-value: 1.12e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVM-NKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11843     2 VRALYDYEGQESDELSFKAGDILTKLeEEDEQGWCKGRLDGRVGLYPANYV 52

Src Homology 3 domain of Sdc25/Cdc25 guanine nucleotide exchange factors; This subfamily is composed of the Saccharomyces cerevisiae guanine nucleotide exchange factors (GEFs) Sdc25 and Cdc25, and similar proteins. These GEFs regulate Ras by stimulating the GDP/GTP exchange on Ras. Cdc25 is involved in the Ras/PKA pathway that plays an important role in the regulation of metabolism, stress responses, and proliferation, depending on available nutrients and conditions. Proteins in this subfamily contain an N-terminal SH3 domain as well as REM (Ras exchanger motif) and RasGEF domains at the C-terminus. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212816 Cd Length: 55 Bit Score: 60.37 E-value: 1.14e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEING-----VTGLFPSNY 412
Cdd:cd11883     2 VVALYDFTPKSKNQLSFKAGDIIYVLNKDPSGWWDGVIISssgkvKRGWFPSNY 55

Third Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212837 [Multi-domain] Cd Length: 57 Bit Score: 60.43 E-value: 1.16e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNK--DDPDWWQ-GEINGVTGLFPSNYV 413
Cdd:cd11904     3 VQALYPFSSSNDEELNFEKGEVMDVIEKpeNDPEWWKcRKANGQVGLVPKNYV 55

SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 394975 [Multi-domain] Cd Length: 47 Bit Score: 60.29 E-value: 1.19e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTG-SIGDRSGIFPS 263
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVLEKsEDGWWKGrNKGGKEGLIPS 47

Second Src Homology 3 domain (SH3B) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CD2AP. SH3B binds to c-Cbl in a site (TPSSRPLR is the core binding motif) distinct from the c-Cbl/SH3A binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212987 [Multi-domain] Cd Length: 55 Bit Score: 59.98 E-value: 1.58e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 362 CQViaMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12054     3 CKV--LFEYVPQNEDELELKVGDIIDINEEVEEGWWSGTLNGKSGLFPSNFVK 53

Src homology 3 domains; Src homology 3 (SH3) domains bind to target proteins through sequences containing proline and hydrophobic amino acids. Pro-containing polypeptides may bind to SH3 domains in 2 different binding orientations.

Pssm-ID: 214620 [Multi-domain] Cd Length: 56 Bit Score: 60.24 E-value: 1.59e-11

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  286 KPEIAQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELqargKKRQKGWFPASHVK 345
Cdd:smart00326   1 EGPQVRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRL----GRGKEGLFPSNYVE 56

C-terminal (or second) Src Homology 3 domain of the p67phox subunit of NADPH oxidase; p67phox, also called Neutrophil cytosol factor 2 (NCF-2), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox plays a regulatory role and contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. It binds, via its C-terminal SH3 domain, to a proline-rich region of p47phox and upon activation, this complex assembles with flavocytochrome b558, the Nox2-p22phox heterodimer. Concurrently, RacGTP translocates to the membrane and interacts with the TPR domain of p67phox, which leads to the activation of NADPH oxidase. The PB1 domain of p67phox binds to its partner PB1 domain in p40phox, and this facilitates the assembly of p47phox-p67phox at the membrane. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212979 [Multi-domain] Cd Length: 53 Bit Score: 59.82 E-value: 1.69e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12046     1 QVVALFSYEASQPEDLEFQKGDVILVLSKVNEDWLEGQCKGKIGIFPSAFVE 52

C-terminal (or second) Src homology 3 domain of VAV proteins; VAV proteins function both as cytoplasmic guanine nucleotide exchange factors (GEFs) for Rho GTPases and scaffold proteins and they play important roles in cell signaling by coupling cell surface receptors to various effector functions. They play key roles in processes that require cytoskeletal reorganization including immune synapse formation, phagocytosis, cell spreading, and platelet aggregation, among others. Vertebrates have three VAV proteins (VAV1, VAV2, and VAV3). VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212764 [Multi-domain] Cd Length: 54 Bit Score: 59.57 E-value: 2.09e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNK-DDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11830     3 KARYDFCARDMRELSLKEGDVVKIYNKkGQQGWWRGEINGRIGWFPSTYVE 53

Src Homology 3 domain superfamily; Src Homology 3 (SH3) domains are protein interaction domains that bind proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. Thus, they are referred to as proline-recognition domains (PRDs). SH3 domains are less selective and show more diverse specificity compared to other PRDs. They have been shown to bind peptide sequences that lack the PxxP motif; examples include the PxxDY motif of Eps8 and the RKxxYxxY sequence in SKAP55. SH3 domain containing proteins play versatile and diverse roles in the cell, including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies, among others. Many members of this superfamily are adaptor proteins that associate with a number of protein partners, facilitating complex formation and signal transduction.

Pssm-ID: 212690 [Multi-domain] Cd Length: 51 Bit Score: 59.40 E-value: 2.34e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 289 IAQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQargkKRQKGWFPASH 343
Cdd:cd00174     1 YARALYDYEAQDDDELSFKKGDIITVLEKDDDGWWEGELN----GGREGLFPANY 51

First Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the first SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212720 [Multi-domain] Cd Length: 53 Bit Score: 59.30 E-value: 2.84e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11786     4 ALYNYEGKEPGDLSFKKGDIILLRKRIDENWYHGECNGKQGFFPASYVQ 52

Second Src Homology 3 domain of FCH and double SH3 domains protein 2; FCHSD2 has a domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. It has only been characterized in silico and its function is unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212827 Cd Length: 56 Bit Score: 59.57 E-value: 2.95e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPD---WWQGEINGVTGLFPSNYVK 414
Cdd:cd11894     2 VKALYDYEGQTDDELSFPEGAIIRILNKENQDddgFWEGEFNGRIGVFPSVLVE 55

Src homology 3 domain of Phospholipase C (PLC) gamma 2; PLCgamma2 is primarily expressed in haematopoietic cells, specifically in B cells. It is activated by tyrosine phosphorylation by B cell receptor (BCR) kinases and is recruited to the plasma membrane where its substrate is located. It is required in pre-BCR signaling and in the maturation of B cells. PLCs catalyze the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG). Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212902 Cd Length: 55 Bit Score: 59.08 E-value: 3.17e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEING-VTGLFPSNYVK 414
Cdd:cd11969     2 VKALYDYRAKRSDELSFCKGALIHNVSKETGGWWKGDYGGkVQHYFPSNYVE 53

Src homology 3 domain of Fyn and Yrk Protein Tyrosine Kinases; Fyn and Yrk (Yes-related kinase) are members of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Fyn, together with Lck, plays a critical role in T-cell signal transduction by phosphorylating ITAM (immunoreceptor tyr activation motif) sequences on T-cell receptors, ultimately leading to the proliferation and differentiation of T-cells. In addition, Fyn is involved in the myelination of neurons, and is implicated in Alzheimer's and Parkinson's diseases. Yrk has been detected only in chickens. It is primarily found in neuronal and epithelial cells and in macrophages. It may play a role in inflammation and in response to injury. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212939 [Multi-domain] Cd Length: 56 Bit Score: 59.29 E-value: 3.39e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE--INGVTGLFPSNYV 413
Cdd:cd12006     4 VALYDYEARTEDDLSFHKGEKFQILNSSEGDWWEARslTTGETGYIPSNYV 54

C2 domain first repeat contained in Rab3-interacting molecule (RIM) proteins; RIMs are believed to organize specialized sites of the plasma membrane called active zones. They also play a role in controlling neurotransmitter release, plasticity processes, as well as memory and learning. RIM contains an N-terminal zinc finger domain, a PDZ domain, and two C-terminal C2 domains (C2A, C2B). C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. Members here have a type-I topology and do not bind Ca2+.

Pssm-ID: 175997 [Multi-domain] Cd Length: 125 Bit Score: 61.11 E-value: 3.76e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISM---GSQSYT--TRTIQDTLNPKWNfncQFFI------KDLYQDVLCLTLF 869
Cdd:cd04031    16 SQLIVTVLQARDLPPRDDGSLRNPYVKVYLlpdRSEKSKrrTKTVKKTLNPEWN---QTFEysnvrrETLKERTLEVTVW 92

                          90       100
                  ....*....|....*....|
gi 1370477838 870 DRDQFSPDDFLGRTEIPVAK 889
Cdd:cd04031    93 DYDRDGENDFLGEVVIDLAD 112

Src Homology 3 domain of Bbc1 and similar domains; This subfamily is composed of Saccharomyces cerevisiae Bbc1p, also called Mti1p (Myosin tail region-interacting protein), and similar proteins. Bbc1p interacts with and regulates type I myosins in yeast, Myo3p and Myo5p, which are involved in actin cytoskeletal reorganization. It also binds and inhibits Las17, a WASp family protein that functions as an activator of the Arp2/3 complex. Bbc1p contains an N-terminal SH3 domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212820 [Multi-domain] Cd Length: 60 Bit Score: 59.28 E-value: 3.88e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTG----SIGDR-SGIFPSNYVKP 268
Cdd:cd11887     5 KALYPYESDHEDDLNFDVGQLITVTEEeDADWYFGeyvdSNGNTkEGIFPKNFVEV 60

Src homology 3 domain of SH3 domain containing Ysc84-like 1 (SH3YL1) protein; SH3YL1 localizes to the plasma membrane and is required for dorsal ruffle formation. It binds phosphoinositides (PIs) with high affinity through its N-terminal SYLF domain (also called DUF500). In addition, SH3YL1 contains a C-terminal SH3 domain which has been reported to bind to N-WASP, dynamin 2, and SHIP2 (a PI 5-phosphatase). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212775 Cd Length: 54 Bit Score: 58.94 E-value: 3.94e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDP--DWWQGEINGVTGLFPSNYVK 414
Cdd:cd11841     1 EVTALYSFEGQQPCDLSFQAGDRITVLTRTDSqfDWWEGRLRGRVGIFPANYVS 54

Second Src Homology 3 domain (SH3B) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CIN85. SH3B has been shown to bind Cbl proline-rich peptides and ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212988 [Multi-domain] Cd Length: 53 Bit Score: 58.85 E-value: 4.36e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 362 CQViaMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12055     2 CQV--AFSYLPQNEDELELKVGDIIEVVGEVEEGWWEGVLNGKTGMFPSNFIK 52

Second Src homology 3 domain (or SH3B) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212771 [Multi-domain] Cd Length: 53 Bit Score: 58.53 E-value: 4.76e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDpDWWQGEINGVT-GLFPSNYVKM 415
Cdd:cd11837     1 TATALYPWRAKKENHLSFAKGDIITVLEQQE-MWWFGELEGGEeGWFPKSYVKE 53

C2 domain found in Rab11-family interacting proteins (FIP) class I; Rab GTPases recruit various effector proteins to organelles and vesicles. Rab11-family interacting proteins (FIPs) are involved in mediating the role of Rab11. FIPs can be divided into three classes: class I FIPs (Rip11a, Rip11b, RCP, and FIP2) which contain a C2 domain after N-terminus of the protein, class II FIPs (FIP3 and FIP4) which contain two EF-hands and a proline rich region, and class III FIPs (FIP1) which exhibits no homology to known protein domains. All FIP proteins contain a highly conserved, 20-amino acid motif at the C-terminus of the protein, known as Rab11/25 binding domain (RBD). Class I FIPs are thought to bind to endocytic membranes via their C2 domain, which interacts directly with phospholipids. Class II FIPs do not have any membrane binding domains leaving much to speculate about the mechanism involving FIP3 and FIP4 interactions with endocytic membranes. The members in this CD are class I FIPs. The exact function of the Rab11 and FIP interaction is unknown, but there is speculation that it involves the role of forming a targeting complex that recruits a group of proteins involved in membrane transport to organelles. The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176064 [Multi-domain] Cd Length: 126 Bit Score: 60.93 E-value: 5.17e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 805 VHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLY-----QDVLCLTLFDRDQFSPDDF 879
Cdd:cd08682     3 VTVLQARGLLCKGKSGTNDAYVIIQLGKEKYSTSVKEKTTSPVWKEECSFELPGLLsgngnRATLQLTVMHRNLLGLDKF 82

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*.
gi 1370477838 880 LGRTEIPvakIRTEQESKG-PMTRRLLLHEVPT------GEVWVRF 918
Cdd:cd08682    83 LGQVSIP---LNDLDEDKGrRRTRWFKLESKPGkddkerGEIEVDI 125

Fifth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212752 [Multi-domain] Cd Length: 50 Bit Score: 58.26 E-value: 5.85e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNY 412
Cdd:cd11818     4 ALYDFTGENEDELSFKAGDIITELESIDEEWMSGELRGKSGIFPKNF 50

Fourth Src homology 3 domain (or SH3D) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212773 [Multi-domain] Cd Length: 58 Bit Score: 58.50 E-value: 6.20e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 363 QVIAmyDYAANNEDELSFSKGQLINVMNKDDPDWWQGEING-----VTGLFPSNYVKM 415
Cdd:cd11839     3 QVIA--PFTATAENQLSLAVGQLVLVRKKSPSGWWEGELQArgkkrQIGWFPANYVKL 58

N-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The N-terminal SH3 domain of the related protein GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212881 [Multi-domain] Cd Length: 54 Bit Score: 58.29 E-value: 7.80e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMN-KDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11948     1 EAVALYSFQATESDELPFQKGDILKILNmEDDQNWYKAELQGREGYIPKNYIKV 54

Src Homology 3 domain of Sorting Nexin 9 and similar proteins; Sorting nexins (SNXs) are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. This subfamily consists of SH3 domain containing SNXs including SNX9, SNX18, SNX33, and similar proteins. SNX9 is localized to plasma membrane endocytic sites and acts primarily in clathrin-mediated endocytosis, while SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212697 [Multi-domain] Cd Length: 55 Bit Score: 58.11 E-value: 8.64e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPD-WWQGE-INGVTGLFPSNYV 413
Cdd:cd11763     1 KVRALYDFDSQPSGELSLRAGEVLTITRQDVGDgWLEGRnSRGEVGLFPSSYV 53

Src homology 3 domain of Abl Interactor proteins; Abl interactor (Abi) proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. They localize to sites of actin polymerization in epithelial adherens junction and immune synapses, as well as to the leading edge of lamellipodia. Vertebrates contain two Abi proteins, Abi1 and Abi2. Abi1 displays a wide expression pattern while Abi2 is highly expressed in the eye and brain. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212760 [Multi-domain] Cd Length: 52 Bit Score: 57.72 E-value: 8.87e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDRSGIFPSNYV 266
Cdd:cd11826     3 VALYDYTADKDDELSFQEGDIIYVTKKNDDgWYEGVLNGVTGLFPGNYV 51

Src Homology 3 domain of Sdc25/Cdc25 guanine nucleotide exchange factors; This subfamily is composed of the Saccharomyces cerevisiae guanine nucleotide exchange factors (GEFs) Sdc25 and Cdc25, and similar proteins. These GEFs regulate Ras by stimulating the GDP/GTP exchange on Ras. Cdc25 is involved in the Ras/PKA pathway that plays an important role in the regulation of metabolism, stress responses, and proliferation, depending on available nutrients and conditions. Proteins in this subfamily contain an N-terminal SH3 domain as well as REM (Ras exchanger motif) and RasGEF domains at the C-terminus. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212816 Cd Length: 55 Bit Score: 57.68 E-value: 9.74e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 289 IAQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARGKKRQKGWFPASH 343
Cdd:cd11883     1 VVVALYDFTPKSKNQLSFKAGDIIYVLNKDPSGWWDGVIISSSGKVKRGWFPSNY 55

C2 domain fourth repeat in Ferlin; Ferlins are involved in vesicle fusion events. Ferlins and other proteins, such as Synaptotagmins, are implicated in facilitating the fusion process when cell membranes fuse together. There are six known human Ferlins: Dysferlin (Fer1L1), Otoferlin (Fer1L2), Myoferlin (Fer1L3), Fer1L4, Fer1L5, and Fer1L6. Defects in these genes can lead to a wide range of diseases including muscular dystrophy (dysferlin), deafness (otoferlin), and infertility (fer-1, fertilization factor-1). Structurally they have 6 tandem C2 domains, designated as (C2A-C2F) and a single C-terminal transmembrane domain, though there is a new study that disputes this and claims that there are actually 7 tandem C2 domains with another C2 domain inserted between C2D and C2E. In a subset of them (Dysferlin, Myoferlin, and Fer1) there is an additional conserved domain called DysF. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the fourth C2 repeat, C2D, and has a type-II topology.

Pssm-ID: 175984 [Multi-domain] Cd Length: 135 Bit Score: 60.25 E-value: 9.77e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 802 RLMVHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWN----FNcQFFI----KDLYQD--VLCLTLFDR 871
Cdd:cd04017     2 QLRAYIYQARDLLAADKSGLSDPFARVSFLNQSQETEVIKETLSPTWDqtliFD-EVELygspEEIAQNppLVVVELFDQ 80

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 872 DQFSPDDFLGRTEI-PVAKIRTEQESKGPmtrrLLLHEV-----PTGEVWVRFDL 920
Cdd:cd04017    81 DSVGKDEFLGRSVAkPLVKLDLEEDFPPK----LQWFPIykggqSAGELLAAFEL 131

Src homology 3 domain of Phospholipase C (PLC) gamma 1; PLCgamma1 is widely expressed and is essential in growth and development. It is activated by the TrkA receptor tyrosine kinase and functions as a key regulator of cell differentiation. It is also the predominant PLCgamma in T cells and is required for T cell and NK cell function. PLCs catalyze the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG). Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212903 Cd Length: 60 Bit Score: 58.08 E-value: 1.03e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 362 CQVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGL-FPSNYVK 414
Cdd:cd11970     4 CAVKALFDYKAQREDELTFTKNAIIQNVEKQEGGWWRGDYGGKKQLwFPSNYVE 57

Src homology 3 domain of eumetazoan Actin-binding protein 1; Abp1, also called drebrin-like protein, is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a helical domain, and a C-terminal SH3 domain. Mammalian Abp1, unlike yeast Abp1, does not contain an acidic domain that interacts with the Arp2/3 complex. It regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. Abp1 deficiency causes abnormal organ structure and function of the spleen, heart, and lung of mice. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212893 [Multi-domain] Cd Length: 54 Bit Score: 57.41 E-value: 1.26e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQG-EINGVTGLFPSNYVKM 415
Cdd:cd11960     2 ARALYDYQAADDTEISFDPGDIITDIEQIDEGWWRGtGPDGTYGLFPANYVEL 54

First Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the first SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212715 [Multi-domain] Cd Length: 53 Bit Score: 57.35 E-value: 1.31e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11781     3 RALYPFKAQSAKELSLKKGDIIYIRRQIDKNWYEGEHNGRVGIFPASYVEI 53

Second Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212834 [Multi-domain] Cd Length: 55 Bit Score: 57.35 E-value: 1.35e-10

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1370477838 368 YDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11901     8 FNYTAEREDELSLVKGTKVIVMEKCSDGWWRGSYNGQVGWFPSNYV 53

First Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the first SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212720 [Multi-domain] Cd Length: 53 Bit Score: 57.37 E-value: 1.43e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11786     2 AKALYNYEGKEPGDLSFKKGDIILLRKRiDENWYHGECNGKQGFFPASYVQV 53

C2A domain first repeat present in Synaptotagmin 7; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 7, a member of class 2 synaptotagmins, is located in presynaptic plasma membranes in neurons, dense-core vesicles in endocrine cells, and lysosomes in fibroblasts. It has been shown to play a role in regulation of Ca2+-dependent lysosomal exocytosis in fibroblasts and may also function as a vesicular Ca2+-sensor. It is distinguished from the other synaptotagmins by having over 12 splice forms. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 176032 [Multi-domain] Cd Length: 125 Bit Score: 59.65 E-value: 1.64e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKACKPNGKSNPYCEISM---GSQSYTTRTIQDTLNPKWNFNCQF--F-IKDLYQDVLCLTLFDRDQFSP 876
Cdd:cd08386    18 LTLKILKAVELPAKDFSGTSDPFVKIYLlpdKKHKLETKVKRKNLNPHWNETFLFegFpYEKLQQRVLYLQVLDYDRFSR 97

                          90
                  ....*....|....*....
gi 1370477838 877 DDFLGRTEIPVAKIRTEQE 895
Cdd:cd08386    98 NDPIGEVSLPLNKVDLTEE 116

First Src homology 3 domain (or SH3A) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212770 [Multi-domain] Cd Length: 55 Bit Score: 56.98 E-value: 1.68e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDD--PDWWQGEINGVTGLFPSNYV 413
Cdd:cd11836     4 ALYAFEARNPDEISFQPGDIIQVDESQVaePGWLAGELKGKTGWFPANYV 53

Src Homology 3 domain of Bbc1 and similar domains; This subfamily is composed of Saccharomyces cerevisiae Bbc1p, also called Mti1p (Myosin tail region-interacting protein), and similar proteins. Bbc1p interacts with and regulates type I myosins in yeast, Myo3p and Myo5p, which are involved in actin cytoskeletal reorganization. It also binds and inhibits Las17, a WASp family protein that functions as an activator of the Arp2/3 complex. Bbc1p contains an N-terminal SH3 domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212820 [Multi-domain] Cd Length: 60 Bit Score: 57.35 E-value: 1.84e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEI---NGVT--GLFPSNYV 413
Cdd:cd11887     4 VKALYPYESDHEDDLNFDVGQLITVTEEEDADWYFGEYvdsNGNTkeGIFPKNFV 58

First Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212862 Cd Length: 54 Bit Score: 56.87 E-value: 2.20e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11929     5 ALCNYRGHNPGDLKFNKGDVILLRRQLDENWYLGEINGVSGIFPASSVEV 54

C-terminal Src Homology 3 domain of the Nebulin family of proteins; Nebulin family proteins contain multiple nebulin repeats, and may contain an N-terminal LIM domain and/or a C-terminal SH3 domain. They have molecular weights ranging from 34 to 900 kD, depending on the number of nebulin repeats, and they all bind actin. They are involved in the regulation of actin filament architecture and function as stabilizers and scaffolds for cytoskeletal structures with which they associate, such as long actin filaments or focal adhesions. Nebulin family proteins that contain a C-terminal SH3 domain include the giant filamentous protein nebulin, nebulette, Lasp1, and Lasp2. Lasp2, also called LIM-nebulette, is an alternatively spliced variant of nebulette. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212723 [Multi-domain] Cd Length: 55 Bit Score: 56.94 E-value: 2.25e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLI-NVMNKDDpDWWQG--EINGVTGLFPSNYVKM 415
Cdd:cd11789     1 RYRAMYDYAAADDDEVSFQEGDVIiNVEIIDD-GWMEGtvQRTGQSGMLPANYVEL 55

Src Homology 3 domain of Pak Interactive eXchange factors; PIX proteins are Rho guanine nucleotide exchange factors (GEFs), which activate small GTPases by exchanging bound GDP for free GTP. They act as GEFs for both Cdc42 and Rac 1, and have been implicated in cell motility, adhesion, neurite outgrowth, and cell polarity. Vertebrates contain two proteins from the PIX subfamily, alpha-PIX and beta-PIX. Alpha-PIX, also called ARHGEF6, is localized in dendritic spines where it regulates spine morphogenesis. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. Beta-PIX play roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212810 [Multi-domain] Cd Length: 53 Bit Score: 56.55 E-value: 2.31e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11877     1 LVRAKFNFEGTNEDELSFDKGDIITVTQVVEgGWWEGTLNGKTGWFPSNYVKE 53

Src Homology 3 domain of Mixed Lineage Kinases; MLKs are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Mammals have four MLKs (MLK1-4), mostly conserved in vertebrates, which contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212809 [Multi-domain] Cd Length: 58 Bit Score: 56.75 E-value: 2.31e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKDGE------WWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11876     2 WTALFDYDARGEDELTLRRGQPVEVLSKDAAvsgdegWWTGKIGDKVGIFPSNYVAP 58

C2 domain third repeat present in Tricalbin-like proteins; 5 to 6 copies of the C2 domain are present in Tricalbin, a yeast homolog of Synaptotagmin, which is involved in membrane trafficking and sorting. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the third C2 repeat, C2C, and has a type-II topology.

Pssm-ID: 176010 [Multi-domain] Cd Length: 120 Bit Score: 58.75 E-value: 2.54e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISM-GSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQdVLCLTLFDRDQFSPDDF 879
Cdd:cd04045     1 GVLRLHIRKANDLKNLEGVGKIDPYVRVLVnGIVKGRTVTISNTLNPVWDEVLYVPVTSPNQ-KITLEVMDYEKVGKDRS 79

                          90
                  ....*....|.
gi 1370477838 880 LGRTEIPVAKI 890
Cdd:cd04045    80 LGSVEINVSDL 90

Src homology 3 domains of the p47phox subunit of NADPH oxidase and similar domains; This family is composed of the tandem SH3 domains of p47phox subunit of NADPH oxidase and Nox Organizing protein 1 (NoxO1), the four SH3 domains of Tks4 (Tyr kinase substrate with four SH3 domains), the five SH3 domains of Tks5, the SH3 domain of obscurin, Myosin-I, and similar domains. Most members of this group also contain Phox homology (PX) domains, except for obscurin and Myosin-I. p47phox and NoxO1 are regulators of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) and nonphagocytic NADPH oxidase Nox1, respectively. They play roles in the activation of their respective NADPH oxidase, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Obscurin is a giant muscle protein that plays important roles in the organization and assembly of the myofibril and the sarcoplasmic reticulum. Type I myosins (Myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212790 [Multi-domain] Cd Length: 53 Bit Score: 56.49 E-value: 2.64e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11856     1 SYVAIADYEAQGDDEISLQEGEVVEVLEKNDSGWWYVRKGDKEGWVPASYLE 52

C2 domain second repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); MCTPs are involved in Ca2+ signaling at the membrane. MCTP is composed of a variable N-terminal sequence, three C2 domains, two transmembrane regions (TMRs), and a short C-terminal sequence. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

Pssm-ID: 176022 [Multi-domain] Cd Length: 116 Bit Score: 58.42 E-value: 2.94e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 807 VIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDDFLGRTEIP 886
Cdd:cd08376     6 LVEGKNLPPMDDNGLSDPYVKFRLGNEKYKSKVCSKTLNPQWLEQFDLHLFDDQSQILEIEVWDKDTGKKDEFIGRCEID 85


                  ....*...
gi 1370477838 887 VAKIRTEQ 894
Cdd:cd08376    86 LSALPREQ 93

Src homology 3 domain of Nitric Oxide Synthase TRaffic INducer; Nostrin is expressed in endothelial and epithelial cells and is involved in the regulation, trafficking and targeting of endothelial NOS (eNOS). It facilitates the endocytosis of eNOS by coordinating the functions of dynamin and the Wiskott-Aldrich syndrome protein (WASP). Increased expression of Nostrin may be correlated to preeclampsia. Nostrin contains an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212757 [Multi-domain] Cd Length: 53 Bit Score: 56.20 E-value: 3.19e-10

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYV 183
Cdd:cd11823     4 ALYSYTANREDELSLQPGDIIEVHEKQDDgWWLGELNGKKGIFPATYV 51

Third Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212750 [Multi-domain] Cd Length: 51 Bit Score: 56.26 E-value: 3.37e-10

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11816     3 VARFDFEGEQEDELSFSEGDVITLKEYVGEEWAKGELNGKIGIFPLNFV 51

C2 domain first repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); MCTPs are involved in Ca2+ signaling at the membrane. MCTP is composed of a variable N-terminal sequence, three C2 domains, two transmembrane regions (TMRs), and a short C-terminal sequence. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-II topology.

Pssm-ID: 176007 [Multi-domain] Cd Length: 121 Bit Score: 58.44 E-value: 3.55e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 802 RLMVHVIEATELKACKPNGKSNPYCEISM-GSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLcLTLFDRDQFSPDDFL 880
Cdd:cd04042     1 QLDIHLKEGRNLAARDRGGTSDPYVKFKYgGKTVYKSKTIYKNLNPVWDEKFTLPIEDVTQPLY-IKVFDYDRGLTDDFM 79

                          90
                  ....*....|....
gi 1370477838 881 GRTEIPVAKIRTEQ 894
Cdd:cd04042    80 GSAFVDLSTLELNK 93

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing (Stac) proteins; Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. This model represents the first C-terminal SH3 domain of Stac1 and Stac3, and the single C-terminal SH3 domain of Stac2. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212767 [Multi-domain] Cd Length: 53 Bit Score: 55.97 E-value: 3.87e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQ-KDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11833     2 YVALYKFKPQENEDLEMRPGDKITLLDdSNEDWWKGKIEDRVGFFPANFV 51

Src homology 3 domain of Yes Protein Tyrosine Kinase; Yes (or c-Yes) is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. c-Yes kinase is the cellular homolog of the oncogenic protein (v-Yes) encoded by the Yamaguchi 73 and Esh sarcoma viruses. It displays functional overlap with other Src subfamily members, particularly Src. It also shows some unique functions such as binding to occludins, transmembrane proteins that regulate extracellular interactions in tight junctions. Yes also associates with a number of proteins in different cell types that Src does not interact with, like JAK2 and gp130 in pre-adipocytes, and Pyk2 in treated pulmonary vein endothelial cells. Although the biological function of Yes remains unclear, it appears to have a role in regulating cell-cell interactions and vesicle trafficking in polarized cells. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212940 [Multi-domain] Cd Length: 58 Bit Score: 56.20 E-value: 3.99e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE--INGVTGLFPSNYV 413
Cdd:cd12007     4 VALYDYEARTTEDLSFKKGERFQIINNTEGDWWEARsiATGKNGYIPSNYV 54

Second Src homology 3 domain of Rab3-interacting molecules (RIMs) binding proteins; RIMs binding proteins (RBPs, RIM-BPs) associate with calcium channels present in photoreceptors, neurons, and hair cells; they interact simultaneously with specific calcium channel subunits, and active zone proteins, RIM1 and RIM2. RIMs are part of the matrix at the presynaptic active zone and are associated with synaptic vesicles through their interaction with the small GTPase Rab3. RIM-BPs play a role in regulating synaptic transmission by serving as adaptors and linking calcium channels with the synaptic vesicle release machinery. RIM-BPs contain three SH3 domains and two to three fibronectin III repeats. Invertebrates contain one, while vertebrates contain at least two RIM-BPs, RIM-BP1 and RIM-BP2. RIM-BP1 is also called peripheral-type benzodiazapine receptor associated protein 1 (PRAX-1). Mammals contain a third protein, RIM-BP3. RIM-BP1 and RIM-BP2 are predominantly expressed in the brain where they display overlapping but distinct expression patterns, while RIM-BP3 is almost exclusively expressed in the testis and is essential in spermiogenesis. The SH3 domains of RIM-BPs bind to the PxxP motifs of RIM1, RIM2, and L-type (alpha1D) and N-type (alpha1B) calcium channel subunits. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212945 Cd Length: 62 Bit Score: 56.15 E-value: 4.13e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1370477838 365 IAMYDYAANN--------EDELSFSKGQLINVMNKDDPD-WWQGEINGVTGLFPSNYVK 414
Cdd:cd12012     3 VALFDYDPLTmspnpdaaEEELPFKEGQLIKVYGDKDADgFYLGEINGRRGLVPCNMVS 61

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. Also included in this subfamily is the second C-terminal SH3 domain of Rho guanine nucleotide exchange factor 37 (ARHGEF37), whose function is still unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212734 [Multi-domain] Cd Length: 57 Bit Score: 55.84 E-value: 5.08e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDD----PDWWQGEINGVTGLFPSNY 412
Cdd:cd11800     1 YYYALYTFEARSPGELSVTEGQVVTVLEKHDlkgnPEWWLVEDRGKQGYVPSNY 54

Src homology 3 domain of Apoptosis Stimulating of p53 proteins (ASPP); The ASPP family of proteins bind to important regulators of apoptosis (p53, Bcl-2, and RelA) and cell growth (APCL, PP1). They share similarity at their C-termini, where they harbor a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain. Vertebrates contain three members of the family: ASPP1, ASPP2, and iASPP. ASPP1 and ASPP2 activate the apoptotic function of the p53 family of tumor suppressors (p53, p63, and p73), while iASPP is an oncoprotein that specifically inhibits p53-induced apoptosis. The expression of ASPP proteins is altered in tumors; ASPP1 and ASPP2 are downregulated whereas iASPP is upregulated is some cancer types. ASPP proteins also bind and regulate protein phosphatase 1 (PP1), and this binding is competitive with p53 binding. The SH3 domain and the ANK repeats of ASPP contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212741 [Multi-domain] Cd Length: 57 Bit Score: 55.46 E-value: 6.64e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPD---WWQGEINGVTGLFPSNYVKM 415
Cdd:cd11807     2 VVYALFDYEAENGDELSFREGDELTVLRKGDDDeteWWWARLNDKEGYVPRNLLGL 57

C2 domain present in cytosolic PhosphoLipase A2 (cPLA2); A single copy of the C2 domain is present in cPLA2 which releases arachidonic acid from membranes initiating the biosynthesis of potent inflammatory mediators such as prostaglandins, leukotrienes, and platelet-activating factor. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. Members of this cd have a type-II topology.

Pssm-ID: 176001 [Multi-domain] Cd Length: 119 Bit Score: 57.66 E-value: 6.66e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 802 RLMVHVIEATELKACKPNGKSNPYCEISMGSQS---YTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFsPDD 878
Cdd:cd04036     1 LLTVRVLRATNITKGDLLSTPDCYVELWLPTASdekKRTKTIKNSINPVWNETFEFRIQSQVKNVLELTVMDEDYV-MDD 79

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 1370477838 879 FLGRTEIPVAKIRTEQeskgPMTRRLLLHEVPTGEVWVRFDLQL 922
Cdd:cd04036    80 HLGTVLFDVSKLKLGE----KVRVTFSLNPQGKEELEVEFLLEL 119

C2 domain first repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); plant subset; MCTPs are involved in Ca2+ signaling at the membrane. Plant-MCTPs are composed of a variable N-terminal sequence, four C2 domains, two transmembrane regions (TMRs), and a short C-terminal sequence. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-II topology.

Pssm-ID: 175989 [Multi-domain] Cd Length: 127 Bit Score: 57.73 E-value: 7.40e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 802 RLMVHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFI---KDLYQDVLCLTLFDRDQFSP-D 877
Cdd:cd04022     1 KLVVEVVDAQDLMPKDGQGSSSAYVELDFDGQKKRTRTKPKDLNPVWNEKLVFNVsdpSRLSNLVLEVYVYNDRRSGRrR 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 1370477838 878 DFLGRTEIPVAKIRTEQESKG---PMTRRLLLHEVpTGEVWVRF 918
Cdd:cd04022    81 SFLGRVRISGTSFVPPSEAVVqryPLEKRGLFSRV-RGEIGLKV 123

C-terminal (or second) Src homology 3 domain of VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and it plays an important role in the development and activation of B and T cells. It is activated by tyrosine phosphorylation to function as a guanine nucleotide exchange factor (GEF) for Rho GTPases following cell surface receptor activation, triggering various effects such as cytoskeletal reorganization, transcription regulation, cell cycle progression, and calcium mobilization. It also serves as a scaffold protein and has been shown to interact with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76, and Syk, among others. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The C-terminal SH3 domain of Vav1 interacts with a wide variety of proteins including cytoskeletal regulators (zyxin), RNA-binding proteins (Sam68), transcriptional regulators, viral proteins, and dynamin 2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212909 [Multi-domain] Cd Length: 54 Bit Score: 55.34 E-value: 7.54e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPD-WWQGEINGVTGLFPSNYVK 414
Cdd:cd11976     4 ARYDFCARDRSELSLKEGDIIKILNKKGQQgWWRGEIYGRVGWFPANYVE 53

Src homology 3 domain of ARHGEF9-like Rho guanine nucleotide exchange factors; Members of this family contain a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. They include the Rho guanine nucleotide exchange factors ARHGEF9, ASEF (also called ARHGEF4), ASEF2, and similar proteins. GEFs activate small GTPases by exchanging bound GDP for free GTP. ARHGEF9 specifically activates Cdc42, while both ASEF and ASEF2 can activate Rac1 and Cdc42. ARHGEF9 is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. ASEF plays a role in angiogenesis and cell migration. ASEF2 is important in cell migration and adhesion dynamics. ASEF exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli), leading to the activation of Rac1 or Cdc42. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212762 [Multi-domain] Cd Length: 53 Bit Score: 55.08 E-value: 8.27e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11828     2 AEALWDHVTMDPEELGFKAGDVIEVLDMSDKDWWWGSIRDEEGWFPASFVRL 53

Src homology 3 domain of Signal Transducing Adaptor Molecule 1; STAM1 is part of the endosomal sorting complex required for transport (ESCRT-0) and is involved in sorting ubiquitinated cargo proteins from the endosome. It may also be involved in the regulation of IL2 and GM-CSF mediated signaling, and has been implicated in neural cell survival. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212897 [Multi-domain] Cd Length: 55 Bit Score: 54.95 E-value: 9.19e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYV 183
Cdd:cd11964     2 KVRAIYDFEAAEDNELTFKAGDIITILDDSDpNWWKGETPQGTGLFPSNFV 52

First Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the first SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212720 [Multi-domain] Cd Length: 53 Bit Score: 54.68 E-value: 1.09e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11786     4 ALYNYEGKEPGDLSFKKGDIILLRKRiDENWYHGECNGKQGFFPASYVQ 52

Fourth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212751 [Multi-domain] Cd Length: 50 Bit Score: 54.79 E-value: 1.15e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNY 265
Cdd:cd11817     3 VALYDFTGETEEDLSFQRGDRILVTEHlDAEWSRGRLNGREGIFPRAF 50

Src homology 3 domain of Lyn Protein Tyrosine Kinase; Lyn is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Lyn is expressed in B lymphocytes and myeloid cells. It exhibits both positive and negative regulatory roles in B cell receptor (BCR) signaling. Lyn, as well as Fyn and Blk, promotes B cell activation by phosphorylating ITAMs (immunoreceptor tyr activation motifs) in CD19 and in Ig components of BCR. It negatively regulates signaling by its unique ability to phosphorylate ITIMs (immunoreceptor tyr inhibition motifs) in cell surface receptors like CD22 and CD5. Lyn also plays an important role in G-CSF receptor signaling by phosphorylating a variety of adaptor molecules. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212937 [Multi-domain] Cd Length: 56 Bit Score: 55.00 E-value: 1.16e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGEWWTGS--IGDRSGIFPSNYV 266
Cdd:cd12004     3 VALYPYDGIHEDDLSFKKGEKLKVIEEHGEWWKARslTTKKEGFIPSNYV 52

C2 domain present in Smad ubiquitination-related factor (Smurf)-like proteins; A single C2 domain is found in Smurf proteins, C2-WW-HECT-domain E3s, which play an important role in the downregulation of the TGF-beta signaling pathway. Smurf proteins also regulate cell shape, motility, and polarity by degrading small guanosine triphosphatases (GTPases). C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. Members here have type-II topology.

Pssm-ID: 176028 [Multi-domain] Cd Length: 123 Bit Score: 56.93 E-value: 1.35e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 824 PYCEISM-GSQSYTTRTIQDTLNPKWNFNCQFFIKDlyQDVLCLTLFDRDQFSPDD--FLGRTEIPVAKIrteQESKGPM 900
Cdd:cd08382    23 PFAVITVdGGQTHSTDVAKKTLDPKWNEHFDLTVGP--SSIITIQVFDQKKFKKKDqgFLGCVRIRANAV---LPLKDTG 97


                  ....*..
gi 1370477838 901 TRRLLLH 907
Cdd:cd08382    98 YQRLDLR 104

First Src Homology 3 domain of SH3 domain containing ring finger protein 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212860 Cd Length: 54 Bit Score: 54.57 E-value: 1.43e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11927     5 ALYNYEGKEPGDLKFSKGDIIILRRQVDENWYHGEVNGIHGFFPTNFVQI 54

Src homology 3 domain of Myosins Ie, If, and similar proteins; Myosins Ie (MyoIe) and If (MyoIf) are nonmuscle, unconventional, long tailed, class I myosins containing an N-terminal motor domain and a myosin tail with TH1, TH2, and SH3 domains. MyoIe interacts with the endocytic proteins, dynamin and synaptojanin-1, through its SH3 domain; it may play a role in clathrin-dependent endocytosis. In the kidney, MyoIe is critical for podocyte function and normal glomerular filtration. Mutations in MyoIe is associated with focal segmental glomerulosclerosis, a disease characterized by massive proteinuria and progression to end-stage kidney disease. MyoIf is predominantly expressed in the immune system; it plays a role in immune cell motility and innate immunity. Mutations in MyoIf may be associated with the loss of hearing. The MyoIf gene has also been found to be fused to the MLL (Mixed lineage leukemia) gene in infant acute myeloid leukemias (AML). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212761 [Multi-domain] Cd Length: 53 Bit Score: 54.34 E-value: 1.54e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDRSGIFPSNYV 266
Cdd:cd11827     4 ALYAYDAQDTDELSFNEGDIIEILKEDPSgWWTGRLRGKEGLFPGNYV 51

Src homology 3 domain of High osmolarity signaling protein Sho1p; Sho1p (or Sho1), also called SSU81 (Suppressor of SUA8-1 mutation), is a yeast membrane protein that regulates adaptation to high salt conditions by activating the HOG (high-osmolarity glycerol) pathway. High salt concentrations lead to the localization to the membrane of the MAPKK Pbs2, which is then activated by the MAPKK Ste11 and in turn, activates the MAPK Hog1. Pbs2 is localized to the membrane though the interaction of its PxxP motif with the SH3 domain of Sho1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212789 [Multi-domain] Cd Length: 55 Bit Score: 54.35 E-value: 1.58e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 366 AMYDYAANNED--ELSFSKGQLINVmnKDDP-DWWQGEI-NGVTGLFPSNYVKM 415
Cdd:cd11855     4 ALYPYDASPDDpnELSFEKGEILEV--SDTSgKWWQARKsNGETGICPSNYLQL 55

First Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212853 [Multi-domain] Cd Length: 55 Bit Score: 54.25 E-value: 1.66e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11920     5 AVYDFKAQTSKELSFKKGDTVYILRKIDQNWYEGEHHGRVGIFPISYVE 53

Second Src homology 3 domain (or SH3B) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212771 [Multi-domain] Cd Length: 53 Bit Score: 54.29 E-value: 1.73e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKDGEWWTGSI-GDRSGIFPSNYVKP 268
Cdd:cd11837     2 ATALYPWRAKKENHLSFAKGDIITVLEQQEMWWFGELeGGEEGWFPKSYVKE 53

Second Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212835 [Multi-domain] Cd Length: 55 Bit Score: 54.24 E-value: 1.74e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1370477838 368 YDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11902     7 FAYVAEREDELSLVKGSRVTVMEKCSDGWWRGSYNGQIGWFPSNYV 52

Third N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP binds the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212730 Cd Length: 51 Bit Score: 54.28 E-value: 1.75e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11796     1 QARVLQDLSAQLDEELDLREGDVVTITGILDKGWFRGELNGRRGIFPEGFV 51

C-terminal (or second) Src homology 3 domain of VAV3 protein; VAV3 is ubiquitously expressed and functions as a phosphorylation-dependent guanine nucleotide exchange factor (GEF) for RhoA, RhoG, and Rac1. It has been implicated to function in the hematopoietic, bone, cerebellar, and cardiovascular systems. VAV3 is essential in axon guidance in neurons that control blood pressure and respiration. It is overexpressed in prostate cancer cells and it plays a role in regulating androgen receptor transcriptional activity. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212911 [Multi-domain] Cd Length: 56 Bit Score: 54.26 E-value: 1.76e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPD-WWQGEINGVTGLFPSNYVK 414
Cdd:cd11978     4 IARYDFCARDMRELSLLKGDVVKIYTKMSTNgWWRGEVNGRVGWFPSTYVE 54

First Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212707 [Multi-domain] Cd Length: 57 Bit Score: 54.35 E-value: 1.76e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVT-------GLFPSNY 412
Cdd:cd11773     4 ALYDYEPQTEDELTIQEDDILYLLEKSDDDWWKVKLKVNSsdddepvGLVPATY 57

Src Homology 3 domain of Small G protein Signaling Modulator 3; SGSM3 is also called Merlin-associated protein (MAP), RUN and SH3 domain-containing protein (RUSC3), RUN and TBC1 domain-containing protein 3 (RUTBC3), Rab GTPase-activating protein 5 (RabGAP5), or Rab GAP-like protein (RabGAPLP). It is expressed ubiquitously and functions as a regulator of small G protein RAP- and RAB-mediated neuronal signaling. It is involved in modulating NGF-mediated neurite outgrowth and differentiation. It also interacts with the tumor suppressor merlin and may play a role in the merlin-associated suppression of cell growth. SGSM3 contains TBC, SH3, and RUN domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212747 Cd Length: 53 Bit Score: 54.04 E-value: 1.88e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQ-ENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11813     1 RAKALLDFERHDDDELGFRKNDIITIISQKdEHCWVGELNGLRGWFPAKFVEL 53

Src homology 3 domain of Nitric Oxide Synthase TRaffic INducer; Nostrin is expressed in endothelial and epithelial cells and is involved in the regulation, trafficking and targeting of endothelial NOS (eNOS). It facilitates the endocytosis of eNOS by coordinating the functions of dynamin and the Wiskott-Aldrich syndrome protein (WASP). Increased expression of Nostrin may be correlated to preeclampsia. Nostrin contains an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212757 [Multi-domain] Cd Length: 53 Bit Score: 54.27 E-value: 1.90e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDRSGIFPSNYV 266
Cdd:cd11823     4 ALYSYTANREDELSLQPGDIIEVHEKQDDgWWLGELNGKKGIFPATYV 51

C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing protein 2 (Stac2); Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac2 contains a single SH3 domain at the C-terminus unlike Stac1 and Stac3, which contain two C-terminal SH3 domains. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212918 Cd Length: 53 Bit Score: 54.18 E-value: 1.95e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDRSGIFPSNYVK 267
Cdd:cd11985     2 YVALYKFLPQENNDLPLQPGDRVMVVDDSNEdWWKGKSGDRVGFFPANFVQ 52

Second Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212708 [Multi-domain] Cd Length: 52 Bit Score: 54.01 E-value: 2.03e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVT-GLFPSNYV 413
Cdd:cd11774     1 QAKALYDYDKQTEEELSFNEGDTLDVYDDSDSDWILVGFNGTQfGFVPANYI 52

First Src Homology 3 domain (SH3A) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CD2AP. SH3A binds to the PXXXPR motif present in c-Cbl and the cytoplasmic domain of cell adhesion protein CD2. Its interaction with CD2 anchors CD2 at sites of cell contact. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212986 Cd Length: 56 Bit Score: 54.08 E-value: 2.07e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLI-NVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12053     1 EYIVEYDYDAVHEDELTIRVGEIIrNVKKLEEEGWLEGELNGRRGMFPDNFVK 53

C2 domain first repeat present in Rabphilin and Double C2 domain; Rabphilin is found neurons and in neuroendrocrine cells, while Doc2 is found not only in the brain but in tissues, including mast cells, chromaffin cells, and osteoblasts. Rabphilin and Doc2s share highly homologous tandem C2 domains, although their N-terminal structures are completely different: rabphilin contains an N-terminal Rab-binding domain (RBD),7 whereas Doc2 contains an N-terminal Munc13-1-interacting domain (MID). C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 176000 [Multi-domain] Cd Length: 123 Bit Score: 56.14 E-value: 2.08e-09

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 802 RLMVHVIEATELKACKPNGKSNPYCEI-----SMGSQSYTTRTIQDTLNPKWNFNCQFF---IKDLYQDVLCLTLFDRDQ 873
Cdd:cd04035    16 ALHCTIIRAKGLKAMDANGLSDPYVKLnllpgASKATKLRTKTVHKTRNPEFNETLTYYgitEEDIQRKTLRLLVLDEDR 95

                          90       100
                  ....*....|....*....|....
gi 1370477838 874 FSpDDFLGRTEIPVAKIRTEQESK 897
Cdd:cd04035    96 FG-NDFLGETRIPLKKLKPNQTKQ 118

C2 domain fifth repeat in Ferlin; Ferlins are involved in vesicle fusion events. Ferlins and other proteins, such as Synaptotagmins, are implicated in facilitating the fusion process when cell membranes fuse together. There are six known human Ferlins: Dysferlin (Fer1L1), Otoferlin (Fer1L2), Myoferlin (Fer1L3), Fer1L4, Fer1L5, and Fer1L6. Defects in these genes can lead to a wide range of diseases including muscular dystrophy (dysferlin), deafness (otoferlin), and infertility (fer-1, fertilization factor-1). Structurally they have 6 tandem C2 domains, designated as (C2A-C2F) and a single C-terminal transmembrane domain, though there is a new study that disputes this and claims that there are actually 7 tandem C2 domains with another C2 domain inserted between C2D and C2E. In a subset of them (Dysferlin, Myoferlin, and Fer1) there is an additional conserved domain called DysF. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the fifth C2 repeat, C2E, and has a type-II topology.

Pssm-ID: 176002 [Multi-domain] Cd Length: 124 Bit Score: 56.02 E-value: 2.25e-09

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 805 VHVIEATELKACKPNGKSNPYCEISMGSQSYTTR--TIQDTLNPKwnFNCQFFIK-DLYQD-VLCLTLFDRDQFSPDDFL 880
Cdd:cd04037     4 VYVVRARNLQPKDPNGKSDPYLKIKLGKKKINDRdnYIPNTLNPV--FGKMFELEaTLPGNsILKISVMDYDLLGSDDLI 81


                  ....*
gi 1370477838 881 GRTEI 885
Cdd:cd04037    82 GETVI 86

Src homology 3 domain of ephexin-1-like SH3 domain containing Rho guanine nucleotide exchange factors; Members of this family contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and C-terminal SH3 domains. They include the Rho guanine nucleotide exchange factors ARHGEF5, ARHGEF16, ARHGEF19, ARHGEF26, ARHGEF27 (also called ephexin-1), and similar proteins, and are also called ephexins because they interact directly with ephrin A receptors. GEFs interact with Rho GTPases via their DH domains to catalyze nucleotide exchange by stabilizing the nucleotide-free GTPase intermediate. They play important roles in neuronal development. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212727 [Multi-domain] Cd Length: 55 Bit Score: 53.88 E-value: 2.44e-09

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGElqaRGKKRQKGWFPASHV 344
Cdd:cd11793     2 VQCVHAYTAQQPDELTLEEGDVVNVLRKMPDGWYEGE---RLRDGERGWFPSSYT 53

N-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also have roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The N-terminal SH3 domain of the related protein GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212880 [Multi-domain] Cd Length: 52 Bit Score: 53.65 E-value: 2.62e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDpDWWQGEINGVTGLFPSNYV 413
Cdd:cd11947     4 GKFDFTASGEDELSFKKGDVLKILSSDD-IWFKAELNGEEGYVPKNFV 50

First C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212895 [Multi-domain] Cd Length: 54 Bit Score: 53.65 E-value: 2.68e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE-INGVTGLFPSNYVKM 415
Cdd:cd11962     3 VVLYDYEKDEDNEIELVEGEIVTNIEMVDEDWWMGTnSKGESGLFPSNYVEL 54

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The C-terminal SH3 domains (SH3c) of GRB2 and GRAP2 have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212739 [Multi-domain] Cd Length: 53 Bit Score: 53.40 E-value: 2.95e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11805     1 RVQALYDFNPQEPGELEFRRGDIITVLDSsDPDWWKGELRGRVGIFPANYVQ 52

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRB2 binds to Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, as well as to the proline-rich C-terminus of FGRF2. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212882 [Multi-domain] Cd Length: 53 Bit Score: 53.69 E-value: 2.99e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11949     2 VQALFDFDPQEDGELGFRRGDFIEVMDNSDpNWWKGACHGQTGMFPRNYVT 52

Src homology 3 domain of Signal Transducing Adaptor Molecules; STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. There are two vertebrate STAMs, STAM1 and STAM2, which may be functionally redundant; vertebrate STAMs contain ITAM motifs. They are part of the endosomal sorting complex required for transport (ESCRT-0). STAM2 deficiency in mice did not cause any obvious abnormality, while STAM1 deficiency resulted in growth retardation. Loss of both STAM1 and STAM2 in mice proved lethal, indicating that STAMs are important for embryonic development. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212754 [Multi-domain] Cd Length: 54 Bit Score: 53.62 E-value: 3.12e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQ-ENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11820     2 KVRALYDFEAAEDNELTFKAGEIITVLDDSdPNWWKGSNHRGEGLFPANFVTA 54

Src Homology 3 domain of Tec-like Protein Tyrosine Kinases; The Tec (Tyrosine kinase expressed in hepatocellular carcinoma) subfamily is composed of Tec, Btk, Bmx (Etk), Itk (Tsk, Emt), Rlk (Txk), and similar proteins. They are cytoplasmic (or nonreceptor) tyr kinases containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. Most Tec subfamily members (except Rlk) also contain an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation. In addition, some members contain the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. Tec kinases are expressed mainly by haematopoietic cells, although Tec and Bmx are also found in endothelial cells. B-cells express Btk and Tec, while T-cells express Itk, Txk, and Tec. Collectively, Tec kinases are expressed in a variety of myeloid cells such as mast cells, platelets, macrophages, and dendritic cells. Each Tec kinase shows a distinct cell-type pattern of expression. The function of Tec kinases in lymphoid cells have been studied extensively. They play important roles in the development, differentiation, maturation, regulation, survival, and function of B-cells and T-cells. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212702 [Multi-domain] Cd Length: 54 Bit Score: 53.43 E-value: 3.23e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQG-EINGVTGLFPSNYVK 414
Cdd:cd11768     1 IVVALYDFQPIEPGDLPLEKGEEYVVLDDSNEHWWRArDKNGNEGYIPSNYVT 53

Src Homology 3 domain of fungal peroxisomal membrane protein Pex13p; Pex13p, located in the peroxisomal membrane, contains two transmembrane regions and a C-terminal SH3 domain. It binds to the peroxisomal targeting type I (PTS1) receptor Pex5p and the docking factor Pex14p through its SH3 domain. It is essential for both PTS1 and PTS2 protein import pathways into the peroxisomal matrix. Pex13p binds Pex14p, which contains a PxxP motif, in a classical fashion to the proline-rich ligand binding site of its SH3 domain. It binds the WxxxF/Y motif of Pex5p in a novel site that does not compete with Pex14p binding. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212705 [Multi-domain] Cd Length: 60 Bit Score: 53.82 E-value: 3.28e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 366 AMYDYA-ANNEDELSFSKGQLINVMNKDDP-----DWWQGEI-NGVTGLFPSNYV 413
Cdd:cd11771     4 ALYDFTpENPEMELSLKKGDIVAVLSKTDPlgrdsEWWKGRTrDGRIGWFPSNYV 58

Src Homology 3 domain of Sdc25/Cdc25 guanine nucleotide exchange factors; This subfamily is composed of the Saccharomyces cerevisiae guanine nucleotide exchange factors (GEFs) Sdc25 and Cdc25, and similar proteins. These GEFs regulate Ras by stimulating the GDP/GTP exchange on Ras. Cdc25 is involved in the Ras/PKA pathway that plays an important role in the regulation of metabolism, stress responses, and proliferation, depending on available nutrients and conditions. Proteins in this subfamily contain an N-terminal SH3 domain as well as REM (Ras exchanger motif) and RasGEF domains at the C-terminus. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212816 Cd Length: 55 Bit Score: 53.44 E-value: 3.30e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGG-----RGWFPKSY 182
Cdd:cd11883     3 VALYDFTPKSKNQLSFKAGDIIYVLNKDPSgWWDGVIISSsgkvkRGWFPSNY 55

First Src Homology 3 domain (SH3A) of CD2-associated protein and similar proteins; This subfamily is composed of the first SH3 domain (SH3A) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3A of both proteins bind to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic domain of the cell adhesion protein CD2. CIN85 SH3A binds to internal proline-rich motifs within the proline-rich region; this intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. CIN85 SH3A has also been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212806 [Multi-domain] Cd Length: 53 Bit Score: 53.42 E-value: 3.46e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11873     1 EVIVEFDYDAEEPDELTLKVGDIITnVKKMEEGWWEGTLNGKRGMFPDNFVK 52

Src Homology 3 domain of SH3 domain-containing protein 21 (SH3D21) and similar proteins; N-terminal SH3 domain of the uncharacterized protein SH3 domain-containing protein 21, and similar uncharacterized domains, it belongs to the CD2AP-like_3 subfamily of proteins. The CD2AP-like_3 subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213018 [Multi-domain] Cd Length: 55 Bit Score: 53.24 E-value: 3.67e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 291 QVTSAYVASGSEQLSLAPGQLILILKKNTS--GWWQGELQARgkkrqKGWFPASHV 344
Cdd:cd12142     3 RVLFDYNPVAPDELALKKGDVIEVISKETEdeGWWEGELNGR-----RGFFPDNFV 53

Src Homology 3 domain of Membrane Protein, Palmitoylated (or MAGUK p55 subfamily member) proteins; The MPP/p55 subfamily of MAGUK (membrane-associated guanylate kinase) proteins includes at least eight vertebrate members (MPP1-7 and CASK), four Drosophila proteins (Stardust, Varicose, CASK and Skiff), and other similar proteins; they all contain one each of the core of three domains characteristic of MAGUK proteins: PDZ, SH3, and guanylate kinase (GuK). In addition, most members except for MPP1 contain N-terminal L27 domains and some also contain a Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. CASK has an additional calmodulin-dependent kinase (CaMK)-like domain at the N-terminus. Members of this subfamily are scaffolding proteins that play important roles in regulating and establishing cell polarity, cell adhesion, and synaptic targeting and transmission, among others. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212796 Cd Length: 61 Bit Score: 53.35 E-value: 3.71e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 366 AMYDYAANNEDE-------LSFSKGQLINVMNKDDPDWWQ----GEINGVTGLFPS 410
Cdd:cd11862     4 ALFDYDPEEDPLipckeagLSFKKGDILQIVNQDDPNWWQarkvGDPNGRAGLIPS 59

Src homology 3 domain of Slit-Robo GTPase Activating Proteins 1, 2, and 3; srGAP1, also called Rho GTPase-Activating Protein 13 (ARHGAP13), is a Cdc42- and RhoA-specific GAP and is expressed later in the development of central nervous system tissues. srGAP2 is expressed in zones of neuronal differentiation. It plays a role in the regeneration of neurons and axons. srGAP3, also called MEGAP (MEntal disorder associated GTPase-Activating Protein), is a Rho GAP with activity towards Rac1 and Cdc42. It impacts cell migration by regulating actin and microtubule cytoskeletal dynamics. The association between srGAP3 haploinsufficiency and mental retardation is under debate. srGAPs are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212888 [Multi-domain] Cd Length: 53 Bit Score: 53.41 E-value: 3.92e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11955     1 EAIAKFDYVGRSARELSFKKGASLLLYHRASDDWWEGRHNGIDGLVPHQYI 51

Src Homology 3 domain of eumetazoan Peroxisomal biogenesis factor 13; PEX13 is a peroxin and is required for protein import into the peroxisomal matrix and membrane. It is an integral membrane protein that is essential for the localization of PEX14 and the import of proteins containing the peroxisome matrix targeting signals, PTS1 and PTS2. Mutations of the PEX13 gene in humans lead to a wide range of peroxisome biogenesis disorders (PBDs), the most severe of which is known as Zellweger syndrome (ZS), a severe multisystem disorder characterized by hypotonia, psychomotor retardation, and neuronal migration defects. PEX13 contains two transmembrane regions and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212798 Cd Length: 58 Bit Score: 53.40 E-value: 4.23e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKD----DPDWWQGEINGVT-GLFPSNYVK 414
Cdd:cd11864     3 RAEYDFVAESEDELSFRAGDKLRLAPKElqprVRGWLLATVDGQKiGLVPANYVK 57

Src homology 3 domain of Blk Protein Tyrosine Kinase; Blk is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. It is expressed specifically in B-cells and is involved in pre-BCR (B-cell receptor) signaling. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212942 [Multi-domain] Cd Length: 54 Bit Score: 53.28 E-value: 4.31e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKDGEWW------TGsigdRSGIFPSNYVKP 268
Cdd:cd12009     2 VIAQYDFVPSNERDLQLKKGEKLQVLKSDGEWWlaksltTG----KEGYIPSNYVAR 54

C-terminal Src Homology 3 domain of NADPH oxidase activator 1; Noxa1 is a homolog of p67phox and is a cytosolic subunit of the nonphagocytic NADPH oxidase complex Nox1, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Noxa1 is co-expressed with Nox1 in colon, stomach, uterus, prostate, and vascular smooth muscle cells, consistent with its regulatory role. It does not interact with p40phox, unlike p67phox, making Nox1 activity independent of p40phox, unlike Nox2. Noxa1 contains TPR, PB1, and C-terminal SH3 domains, but lacks the central SH3 domain that is present in p67phox. The TPR domain binds activated GTP-bound Rac. The C-terminal SH3 domain binds the polyproline motif found at the C-terminus of Noxo1, a homolog of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212980 Cd Length: 53 Bit Score: 53.28 E-value: 4.36e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd12047     1 RMVAQHDYSAQGPEDLEFSQGDTIDILSEVNQEWLEGHCDGRIGIFPKCFA 51

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing protein 3 (Stac3); Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212919 [Multi-domain] Cd Length: 53 Bit Score: 52.99 E-value: 4.61e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQ-KDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11986     2 FVALYRFKALEKDDLDFHPGERITVIDdSNEEWWRGKIGEKTGYFPMNFI 51

Third Src Homology 3 domain (SH3C) of CD2-associated protein and similar proteins; This subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212808 [Multi-domain] Cd Length: 55 Bit Score: 52.74 E-value: 5.71e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE---WWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11875     4 VLFDYEAENEDELTLREGDIVTILSKDCEdkgWWKGELNGKRGVFPDNFVEP 55

Src homology 3 domain of Endophilin-A; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain three endophilin-A isoforms (A1, A2, and A3). Endophilin-A proteins are enriched in the brain and play multiple roles in receptor-mediated endocytosis. They tubulate membranes and regulate calcium influx into neurons to trigger the activation of the endocytic machinery. They are also involved in the sorting of plasma membrane proteins, actin filament assembly, and the uncoating of clathrin-coated vesicles for fusion with endosomes. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212737 [Multi-domain] Cd Length: 55 Bit Score: 52.65 E-value: 5.73e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11803     5 ALYDFEPENEGELGFKEGDIItLTNQIDENWYEGMVNGQSGFFPVNYV 52

Src Homology 3 domain of Amphiphysin and related domains; Amphiphysins function primarily in endocytosis and other membrane remodeling events. They exist in several isoforms and mammals possess two amphiphysin proteins from distinct genes. Amphiphysin I proteins, enriched in the brain and nervous system, contain domains that bind clathrin, Adaptor Protein complex 2 (AP2), dynamin, and synaptojanin. They function in synaptic vesicle endocytosis. Human autoantibodies to amphiphysin I hinder GABAergic signaling and contribute to the pathogenesis of paraneoplastic stiff-person syndrome. Some amphiphysin II isoforms, also called Bridging integrator 1 (Bin1), are localized in many different tissues and may function in intracellular vesicle trafficking. In skeletal muscle, Bin1 plays a role in the organization and maintenance of the T-tubule network. Mutations in Bin1 are associated with autosomal recessive centronuclear myopathy. Amphiphysins contain an N-terminal BAR domain with an additional N-terminal amphipathic helix (an N-BAR), a variable central domain, and a C-terminal SH3 domain. The SH3 domain of amphiphysins bind proline-rich motifs present in binding partners such as dynamin, synaptojanin, and nsP3. It also belongs to a subset of SH3 domains that bind ubiquitin in a site that overlaps with the peptide binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212724 [Multi-domain] Cd Length: 64 Bit Score: 53.10 E-value: 6.03e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPD-----WWQG--EINGVTGLFPSNYVK 414
Cdd:cd11790     5 VRATHDYTAEDTDELTFEKGDVILVIPFDDPEeqdegWLMGvkESTGCRGVFPENFTE 62

Second Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the second SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212716 [Multi-domain] Cd Length: 53 Bit Score: 52.74 E-value: 6.23e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11782     1 EARAKYNFNADTGVELSFRKGDVITLTRRVDENWYEGRIGGRQGIFPVSYVQ 52

Src homology 3 domain of Alpha Spectrin; Spectrin is a major structural component of the red blood cell membrane skeleton and is important in erythropoiesis and membrane biogenesis. It is a flexible, rope-like molecule composed of two subunits, alpha and beta, which consist of many spectrin-type repeats. Alpha and beta spectrin associate to form heterodimers and tetramers; spectrin tetramer formation is critical for red cell shape and deformability. Defects in alpha spectrin have been associated with inherited hemolytic anemias including hereditary spherocytosis (HSp), hereditary elliptocytosis (HE), and hereditary pyropoikilocytosis (HPP). Alpha spectrin contains a middle SH3 domain and a C-terminal EF-hand binding motif in addition to multiple spectrin repeats. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212742 [Multi-domain] Cd Length: 53 Bit Score: 52.49 E-value: 6.57e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11808     2 VVALYDYQEKSPREVSMKKGDILTLLNSSNKDWWKVEVNDRQGFVPAAYVK 52

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 3 (PACSIN3); PACSIN 3 or Syndapin III (Synaptic dynamin-associated protein III) is expressed ubiquitously and regulates glucose uptake in adipocytes through its role in GLUT1 trafficking. It also modulates the subcellular localization and stimulus-specific function of the cation channel TRPV4. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212930 [Multi-domain] Cd Length: 56 Bit Score: 52.65 E-value: 6.83e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKG-QLINVMNKDDPDWWQGEI-NGVTGLFPSNYVK 414
Cdd:cd11997     3 RVRALYDYTGQEADELSFKAGeELLKIGEEDEQGWCKGRLlSGRIGLYPANYVE 56

Fifth Src homology 3 domain (or SH3E) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212774 [Multi-domain] Cd Length: 53 Bit Score: 52.42 E-value: 7.38e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11840     4 ALFPYTAQNEDELSFQKGDIINVLSKDDpDWWRGELNGQTGLFPSNYVE 52

First Src homology 3 domain (or SH3A) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212920 [Multi-domain] Cd Length: 55 Bit Score: 52.31 E-value: 8.52e-09

                          10        20        30
                  ....*....|....*....|....*....|...
gi 1370477838  15 IYSVDEKTVGEPGWLYGSFQGNFGWFPCNYVEK 47
Cdd:cd11987    23 IVMVDESQTGEPGWLGGELKGKTGWFPANYAEK 55

Src Homology 3 domain of Pak Interactive eXchange factors; PIX proteins are Rho guanine nucleotide exchange factors (GEFs), which activate small GTPases by exchanging bound GDP for free GTP. They act as GEFs for both Cdc42 and Rac 1, and have been implicated in cell motility, adhesion, neurite outgrowth, and cell polarity. Vertebrates contain two proteins from the PIX subfamily, alpha-PIX and beta-PIX. Alpha-PIX, also called ARHGEF6, is localized in dendritic spines where it regulates spine morphogenesis. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. Beta-PIX play roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212810 [Multi-domain] Cd Length: 53 Bit Score: 51.93 E-value: 1.01e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11877     4 AKFNFEGTNEDELSFDKGDIITVTQVvEGGWWEGTLNGKTGWFPSNYVKE 53

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 2; ASAP2 is also called DDEF2 (Development and Differentiation Enhancing Factor 2), AMAP2, centaurin beta-3, or PAG3. It mediates the functions of Arf GTPases vial dual mechanisms: it exhibits GTPase activating protein (GAP) activity towards class I (Arf1) and II (Arf5) Arfs; and it binds class III Arfs (GTP-Arf6) stably without GAP activity. It binds paxillin and is implicated in Fcgamma receptor-mediated phagocytosis in macrophages and in cell migration. ASAP2 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212899 Cd Length: 56 Bit Score: 51.88 E-value: 1.13e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEING---VTGLFPSNYV 413
Cdd:cd11966     1 RVKALYNCVADNPDELTFSEGEIIIVDGEEDKEWWIGHIDGeptRRGAFPVSFV 54

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing proteins; ASAPs are Arf GTPase activating proteins (GAPs) and they function in regulating cell growth, migration, and invasion. They contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. Vertebrates contain at least three members, ASAP1, ASAP2, and ASAP3, but some ASAP3 proteins do not seem to harbor a C-terminal SH3 domain. ASAP1 and ASAP2 show GTPase activating protein (GAP) activity towards Arf1 and Arf5. They do not show GAP activity towards Arf6, but are able to mediate Arf6 signaling by binding stably to GTP-Arf6. ASAP3 is an Arf6-specific GAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212755 [Multi-domain] Cd Length: 53 Bit Score: 51.93 E-value: 1.15e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVT-QKDGEWWTGSI---GDRSGIFPSNY 265
Cdd:cd11821     4 ALYDCQADNDDELTFSEGEIIVVTgEEDDEWWEGHIegdPSRRGVFPVSF 53

Src Homology 3 domain of Small G protein Signaling Modulator 3; SGSM3 is also called Merlin-associated protein (MAP), RUN and SH3 domain-containing protein (RUSC3), RUN and TBC1 domain-containing protein 3 (RUTBC3), Rab GTPase-activating protein 5 (RabGAP5), or Rab GAP-like protein (RabGAPLP). It is expressed ubiquitously and functions as a regulator of small G protein RAP- and RAB-mediated neuronal signaling. It is involved in modulating NGF-mediated neurite outgrowth and differentiation. It also interacts with the tumor suppressor merlin and may play a role in the merlin-associated suppression of cell growth. SGSM3 contains TBC, SH3, and RUN domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212747 Cd Length: 53 Bit Score: 51.73 E-value: 1.24e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11813     4 ALLDFERHDDDELGFRKNDIITIISQKDEHCWVGELNGLRGWFPAKFVEL 53

Fifth Src homology 3 domain (or SH3E) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212929 [Multi-domain] Cd Length: 54 Bit Score: 51.91 E-value: 1.28e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQKDG-EWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11996     2 QVIAMYDYTANNEDELSFSKGQLINVLNKDDpDWWQGEINGVTGLFPSNYVK 53

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 1 (PACSIN1) and PACSIN 2; PACSIN 1 or Syndapin I (Synaptic dynamin-associated protein I) is expressed specifically in the brain and is localized in neurites and synaptic boutons. It binds the brain-specific proteins dynamin I, synaptojanin, synapsin I, and neural Wiskott-Aldrich syndrome protein (nWASP), and functions as a link between the cytoskeletal machinery and synaptic vesicle endocytosis. PACSIN 1 interacts with huntingtin and may be implicated in the neuropathology of Huntington's disease. PACSIN 2 or Syndapin II is expressed ubiquitously and is involved in the regulation of tubulin polymerization. It associates with Golgi membranes and forms a complex with dynamin II which is crucial in promoting vesicle formation from the trans-Golgi network. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212931 [Multi-domain] Cd Length: 56 Bit Score: 51.87 E-value: 1.30e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKG-QLINVMNKDDPDWWQGEI-NGVTGLFPSNYVK 414
Cdd:cd11998     2 RVRALYDYDGQEQDELSFKAGdELTKLEDEDEQGWCKGRLdSGQVGLYPANYVE 55

Src homology 3 domain of Signal Transducing Adaptor Molecule 2; STAM2, also called EAST (Epidermal growth factor receptor-associated protein with SH3 and TAM domain) or Hbp (Hrs binding protein), is part of the endosomal sorting complex required for transport (ESCRT-0). It plays a role in sorting mono-ubiquinated endosomal cargo for trafficking to the lysosome for degradation. It is also involved in the regulation of exocytosis. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212896 [Multi-domain] Cd Length: 57 Bit Score: 51.94 E-value: 1.31e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYV 183
Cdd:cd11963     3 KVRALYDFEAVEDNELTFKHGEIIIVLDDSDaNWWKGENHRGVGLFPSNFV 53

Ca2+-dependent lipid-binding protein, contains C2 domain [General function prediction only];

Pssm-ID: 227371 [Multi-domain] Cd Length: 1227 Bit Score: 59.00 E-value: 1.43e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  801 GRLMVHVIEATELKACKPNGKSNPYCEISMGSQS-YTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDDF 879
Cdd:COG5038   1040 GYLTIMLRSGENLPSSDENGYSDPFVKLFLNEKSvYKTKVVKKTLNPVWNEEFTIEVLNRVKDVLTINVNDWDSGEKNDL 1119

                           90
                   ....*....|....*..
gi 1370477838  880 LGRTEIPVAKIRTEQES 896
Cdd:COG5038   1120 LGTAEIDLSKLEPGGTT 1136

Second Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212749 [Multi-domain] Cd Length: 52 Bit Score: 51.41 E-value: 1.51e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11815     3 VVLHDFPAEHSDDLSLNSGEIVYLLEKIDTEWYRGKCKNTTGIFPANHVK 52

C2A domain first repeat present in Synaptotagmins 1, 5, 6, 9, and 10; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 1, a member of class 1 synaptotagmins, is located in the brain and endocranium and localized to the synaptic vesicles and secretory granules. It functions as a Ca2+ sensor for fast exocytosis as do synaptotagmins 5, 6, and 10. It is distinguished from the other synaptotagmins by having an N-glycosylated N-terminus. Synaptotagmins 5, 6, and 10, members of class 3 synaptotagmins, are located primarily in the brain and localized to the active zone and plasma membrane. They is distinguished from the other synaptotagmins by having disulfide bonds at its N-terminus. Synaptotagmin 6 also regulates the acrosome reaction, a unique Ca2+-regulated exocytosis, in sperm. Synaptotagmin 9, a class 5 synaptotagmins, is located in the brain and localized to the synaptic vesicles. It is thought to be a Ca2+-sensor for dense-core vesicle exocytosis. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 176031 [Multi-domain] Cd Length: 124 Bit Score: 53.81 E-value: 1.62e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISM---GSQSYTTRTIQDTLNPKwnFNCQFFIKDLYQDV----LCLTLFDRDQ 873
Cdd:cd08385    16 NQLTVGIIQAADLPAMDMGGTSDPYVKVYLlpdKKKKFETKVHRKTLNPV--FNETFTFKVPYSELgnktLVFSVYDFDR 93

                          90       100
                  ....*....|....*....|..
gi 1370477838 874 FSPDDFLGRTEIPVAKIRTEQE 895
Cdd:cd08385    94 FSKHDLIGEVRVPLLTVDLGHV 115

C-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also has roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRAP2 binds to different motifs found in substrate peptides including the typical PxxP motif in hematopoietic progenitor kinase 1 (HPK1), the RxxK motif in SLP-76 and HPK1, and the RxxxxK motif in phosphatase-like protein HD-PTP. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212883 [Multi-domain] Cd Length: 53 Bit Score: 51.36 E-value: 1.64e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILV-TQKDGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11950     4 ALYDFEALEDDELGFNSGDVIEVlDSSNPSWWKGRLHGKLGLFPANYVAP 53

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the third SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212714 [Multi-domain] Cd Length: 55 Bit Score: 51.53 E-value: 1.86e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQG--EINGVTGLFPSNYVK 414
Cdd:cd11780     4 ALYSYTPQNEDELELREGDIVYVMEKCDDGWFVGtsERTGLFGTFPGNYVA 54

C2 domain found in fungal Ingression 1 (Inn1) proteins; Saccharomyces cerevisiae Inn1 associates with the contractile actomyosin ring at the end of mitosis and is needed for cytokinesis. The C2 domain of Inn1, located at the N-terminus, is required for ingression of the plasma membrane. The C-terminus is relatively unstructured and contains eight PXXP motifs that are thought to mediate interaction of Inn1 with other proteins with SH3 domains in the cytokinesis proteins Hof1 (an F-BAR protein) and Cyk3 (whose overexpression can restore primary septum formation in Inn1Delta cells) as well as recruiting Inn1 to the bud-neck by binding to Cyk3. Inn1 and Cyk3 appear to cooperate in activating chitin synthase Chs2 for primary septum formation, which allows coordination of actomyosin ring contraction with ingression of the cleavage furrow. It is thought that the C2 domain of Inn1 helps to preserve the link between the actomyosin ring and the plasma membrane, contributing both to membrane ingression, as well as to stability of the contracting ring. Additionally, Inn1 might induce curvature of the plasma membrane adjacent to the contracting ring, thereby promoting ingression of the membrane. It has been shown that the C2 domain of human synaptotagmin induces curvature in target membranes and thereby contributes to fusion of these membranes with synaptic vesicles. The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176063 [Multi-domain] Cd Length: 118 Bit Score: 53.41 E-value: 1.86e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELkackPN----GKSNPYCEISMGSQSYTTRTI----QdtlNPKWNFNCQFFIKDLYQDVLCLTLFDrD 872
Cdd:cd08681     1 GTLVVVVLKARNL----PNkrklDKQDPYCVLRIGGVTKKTKTDfrggQ---HPEWDEELRFEITEDKKPILKVAVFD-D 72

                          90       100
                  ....*....|....*....|...
gi 1370477838 873 QFSPDDFLGRTEIPVAKIRTEQE 895
Cdd:cd08681    73 DKRKPDLIGDTEVDLSPALKEGE 95

Src Homology 3 domain of Myosin XV; This subfamily is composed of proteins with similarity to Myosin XVa. Myosin XVa is an unconventional myosin that is critical for the normal growth of mechanosensory stereocilia of inner ear hair cells. Mutations in the myosin XVa gene are associated with nonsyndromic hearing loss. Myosin XVa contains a unique N-terminal extension followed by a motor domain, light chain-binding IQ motifs, and a tail consisting of a pair of MyTH4-FERM tandems separated by a SH3 domain, and a PDZ domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212817 [Multi-domain] Cd Length: 56 Bit Score: 51.17 E-value: 2.07e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNK---DDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11884     2 VVAVRAYITRDQTLLSFHKGDVIKLLPKegpLDPGWLFGTLDGRSGAFPKEYV 54

Src homology 3 domain of Endophilin-A; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain three endophilin-A isoforms (A1, A2, and A3). Endophilin-A proteins are enriched in the brain and play multiple roles in receptor-mediated endocytosis. They tubulate membranes and regulate calcium influx into neurons to trigger the activation of the endocytic machinery. They are also involved in the sorting of plasma membrane proteins, actin filament assembly, and the uncoating of clathrin-coated vesicles for fusion with endosomes. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212737 [Multi-domain] Cd Length: 55 Bit Score: 51.11 E-value: 2.17e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKII 186
Cdd:cd11803     3 CRALYDFEPENEGELGFKEGDIITLTNQiDENWYEGMVNGQSGFFPVNYVEVL 55

Src Homology 3 domain of Mixed Lineage Kinases 1, 2, and 3; MLKs 1, 2, and 3 are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Little is known about the specific function of MLK1, also called MAP3K9. It is capable of activating the c-Jun N-terminal kinase pathway. Mice lacking both MLK1 and MLK2 are viable, fertile, and have normal life spans. MLK2, also called MAP3K10, is abundant in brain, skeletal muscle, and testis. It functions upstream of the MAPK, c-Jun N-terminal kinase. It binds hippocalcin, a calcium-sensor protein that protects neurons against calcium-induced cell death. Both MLK2 and hippocalcin may be associated with the pathogenesis of Parkinson's disease. MLK3, also called MAP3K11, is highly expressed in breast cancer cells and its signaling through c-Jun N-terminal kinase has been implicated in the migration, invasion, and malignancy of cancer cells. It also functions as a negative regulator of Inhibitor of Nuclear Factor-KappaB Kinase (IKK) and thus, impacts inflammation and immunity. MLKs contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212992 [Multi-domain] Cd Length: 58 Bit Score: 51.31 E-value: 2.19e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKDGE------WWTGSIGDRSGIFPSNYVKP 268
Cdd:cd12059     2 WTAVFDYEASAEDELTLRRGDRVEVLSKDSAvsgdegWWTGKINDRVGIFPSNYVTS 58

C2 domain present in Calpain proteins; A single C2 domain is found in calpains (EC 3.4.22.52, EC 3.4.22.53), calcium-dependent, non-lysosomal cysteine proteases. Caplains are classified as belonging to Clan CA by MEROPS and include six families: C1, C2, C10, C12, C28, and C47. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176011 [Multi-domain] Cd Length: 126 Bit Score: 53.44 E-value: 2.21e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 805 VHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLcLTLFDRDQFSpDDFLGRTE 884
Cdd:cd04046     7 VHVHSAEGLSKQDSGGGADPYVIIKCEGESVRSPVQKDTLSPEFDTQAIFYRKKPRSPIK-IQVWNSNLLC-DEFLGQAT 84


                  ....
gi 1370477838 885 IPVA 888
Cdd:cd04046    85 LSAD 88

First Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212861 Cd Length: 54 Bit Score: 51.08 E-value: 2.36e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11928     5 ALYSYEGKEPGDLKFNKGDIIILRRKVDENWYHGELNGCHGFLPASYIQC 54

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 1; ASAP1 is also called DDEF1 (Development and Differentiation Enhancing Factor 1), AMAP1, centaurin beta-4, or PAG2. an Arf GTPase activating protein (GAP) with activity towards Arf1 and Arf5 but not Arf6. However, it has been shown to bind GTP-Arf6 stably without GAP activity. It has been implicated in cell growth, migration, and survival, as well as in tumor invasion and malignancy. It binds paxillin and cortactin, two components of invadopodia which are essential for tumor invasiveness. It also binds focal adhesion kinase (FAK) and the SH2/SH3 adaptor CrkL. ASAP1 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212898 [Multi-domain] Cd Length: 57 Bit Score: 51.16 E-value: 2.40e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGV---TGLFPSNYVKM 415
Cdd:cd11965     1 RVKTIYDCQADNDDELTFVEGEVIIVTGEEDQEWWIGHIEGQperKGVFPVSFVHI 56

C-terminal Src Homology 3 domain of the p67phox subunit of NADPH oxidase and similar proteins; This subfamily is composed of p67phox, NADPH oxidase activator 1 (Noxa1), and similar proteins. p67phox, also called Neutrophil cytosol factor 2 (NCF-2), and Noxa1 are homologs and are the cytosolic subunits of the phagocytic (Nox2) and nonphagocytic (Nox1) NADPH oxidase complexes, respectively. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox and Noxa1 play regulatory roles. p67phox contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. Noxa1 has a similar domain architecture except it is lacking the N-terminal SH3 domain. The TPR domain of both binds activated GTP-bound Rac, while the C-terminal SH3 domain of p67phox and Noxa1 binds the polyproline motif found at the C-terminus of p47phox and Noxo1, respectively. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212803 [Multi-domain] Cd Length: 53 Bit Score: 50.99 E-value: 2.41e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11870     1 QVVALHRYEAQGPEDLGFREGDTIDVLSEVNEAWLEGHSDGRVGIFPKCFVV 52

C2 domain present in the putative elicitor-responsive gene; In plants elicitor-responsive proteins are triggered in response to specific elicitor molecules such as glycolproteins, peptides, carbohydrates and lipids. A host of defensive responses are also triggered resulting in localized cell death. Antimicrobial secondary metabolites, such as phytoalexins, or defense-related proteins, including pathogenesis-related (PR) proteins are also produced. There is a single C2 domain present here. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. Members have a type-II topology.

Pssm-ID: 176014 [Multi-domain] Cd Length: 124 Bit Score: 53.11 E-value: 2.41e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDT-LNPKWNFNCQFFIKDLYQDV---LCLTLFDRDQFSP 876
Cdd:cd04049     1 GTLEVLLISAKGLQDTDFLGKIDPYVIIQCRTQERKSKVAKGDgRNPEWNEKFKFTVEYPGWGGdtkLILRIMDKDNFSD 80

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 1370477838 877 DDFLGRTEIPVAKIRTEQESKGpmtrrlLLHEVPTGE 913
Cdd:cd04049    81 DDFIGEATIHLKGLFEEGVEPG------TAELVPAKY 111

Src homology 3 domain of Blk Protein Tyrosine Kinase; Blk is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. It is expressed specifically in B-cells and is involved in pre-BCR (B-cell receptor) signaling. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212942 [Multi-domain] Cd Length: 54 Bit Score: 50.97 E-value: 2.80e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMnKDDPDWWQGE--INGVTGLFPSNYV 413
Cdd:cd12009     2 VIAQYDFVPSNERDLQLKKGEKLQVL-KSDGEWWLAKslTTGKEGYIPSNYV 52

C2 domain second repeat present in Rabphilin and Double C2 domain; Rabphilin is found neurons and in neuroendrocrine cells, while Doc2 is found not only in the brain but in tissues, including mast cells, chromaffin cells, and osteoblasts. Rabphilin and Doc2s share highly homologous tandem C2 domains, although their N-terminal structures are completely different: rabphilin contains an N-terminal Rab-binding domain (RBD),7 whereas Doc2 contains an N-terminal Munc13-1-interacting domain (MID). C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 176030 [Multi-domain] Cd Length: 133 Bit Score: 53.12 E-value: 2.96e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEIS----MGSQS-YTTRTIQDTLNPKWNFNCQFFIK--DLYQDVLCLTLFDRDQ 873
Cdd:cd08384    13 RGLIVGIIRCVNLAAMDANGYSDPFVKLYlkpdAGKKSkHKTQVKKKTLNPEFNEEFFYDIKhsDLAKKTLEITVWDKDI 92


                  ....*...
gi 1370477838 874 FSPDDFLG 881
Cdd:cd08384    93 GKSNDYIG 100

C-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domains (SH3c) of the related proteins, GRB2 and GRAP2, have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212884 Cd Length: 53 Bit Score: 50.57 E-value: 3.01e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11951     4 AQYDFSAEDPSQLSFRRGDIIEVLDCpDPNWWRGRISGRVGFFPRNYVHP 53

Src homology 3 domain of Protein arginine N-methyltransferase 2; PRMT2, also called HRMT1L1, belongs to the arginine methyltransferase protein family. It functions as a coactivator to both estrogen receptor alpha (ER-alpha) and androgen receptor (AR), presumably through arginine methylation. The ER-alpha transcription factor is involved in cell proliferation, differentiation, morphogenesis, and apoptosis, and is also implicated in the development and progression of breast cancer. PRMT2 and its variants are upregulated in breast cancer cells and may be involved in modulating the ER-alpha signaling pathway during formation of breast cancer. PRMT2 also plays a role in regulating the function of E2F transcription factors, which are critical cell cycle regulators, by binding to the retinoblastoma gene product (RB). It contains an N-terminal SH3 domain and an AdoMet binding domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212740 [Multi-domain] Cd Length: 53 Bit Score: 50.47 E-value: 3.23e-08

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHV 344
Cdd:cd11806     8 FVATDDSQLSFESGDKLLVLRKPSVDWWWAEHNG-----CCGYIPASHL 51

C2A domain first repeat present in Synaptotagmin 8; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 176033 [Multi-domain] Cd Length: 124 Bit Score: 52.79 E-value: 3.45e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISM---GSQSYTTRTIQDTLNPKW--NFNCQFFIKDLYQDVLCLTLFDRDQFS 875
Cdd:cd08387    16 GILNVKLIQARNLQPRDFSGTADPYCKVRLlpdRSNTKQSKIHKKTLNPEFdeSFVFEVPPQELPKRTLEVLLYDFDQFS 95

                          90
                  ....*....|....*
gi 1370477838 876 PDDFLGRTEIPVAKI 890
Cdd:cd08387    96 RDECIGVVELPLAEV 110

Second C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212894 [Multi-domain] Cd Length: 53 Bit Score: 50.60 E-value: 3.51e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLE-QQENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11961     2 AKALYDYDAAEDNELSFFENDKIINIEfVDDDWWLGECHGSRGLFPSNYVE 52

N-terminal Src Homology 3 domain of Ct10 Regulator of Kinase adaptor proteins; CRK adaptor proteins consists of SH2 and SH3 domains, which bind tyrosine-phosphorylated peptides and proline-rich motifs, respectively. They function downstream of protein tyrosine kinases in many signaling pathways started by various extracellular signals, including growth and differentiation factors. Cellular CRK (c-CRK) contains a single SH2 domain, followed by N-terminal and C-terminal SH3 domains. It is involved in the regulation of many cellular processes including cell growth, motility, adhesion, and apoptosis. CRK has been implicated in the malignancy of various human cancers. The N-terminal SH3 domain of CRK binds a number of target proteins including DOCK180, C3G, SOS, and cABL. The CRK family includes two alternatively spliced protein forms, CRKI and CRKII, that are expressed by the CRK gene, and the CRK-like (CRKL) protein, which is expressed by a distinct gene (CRKL). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212692 [Multi-domain] Cd Length: 55 Bit Score: 50.44 E-value: 3.60e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE-INGVTGLFPSNYV 413
Cdd:cd11758     3 VRALFDFPGNDDEDLPFKKGEILTVIRKPEEQWWNARnSEGKTGMIPVPYV 53

Src Homology 3 domain of Abelson helper integration site-1 (AHI-1); AHI-1, also called Jouberin, is expressed in high levels in the brain, gonad tissues, and skeletal muscle. It is an adaptor protein that interacts with the small GTPase Rab8a and regulates it distribution and function, affecting cilium formation and vesicle transport. Mutations in the AHI-1 gene can cause Joubert syndrome, a disorder characterized by brainstem malformations, cerebellar aplasia/hypoplasia, and retinal dystrophy. AHI-1 variation is also associated with susceptibility to schizophrenia and type 2 diabetes mellitus progression. AHI-1 contains WD40 and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212746 [Multi-domain] Cd Length: 52 Bit Score: 50.59 E-value: 3.70e-08

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGE-VHGGRGWFPKSYV 183
Cdd:cd11812     4 ALYDYTANRSDELTIHRGDIIRVLYKdNDNWWFGSlVNGQQGYFPANYV 52

First Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212861 Cd Length: 54 Bit Score: 50.31 E-value: 4.16e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11928     4 KALYSYEGKEPGDLKFNKGDIIILRRKvDENWYHGELNGCHGFLPASYIQ 53

Second C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212894 [Multi-domain] Cd Length: 53 Bit Score: 50.22 E-value: 4.40e-08

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11961     4 ALYDYDAAEDNELSFFENDKIInIEFVDDDWWLGECHGSRGLFPSNYVE 52

SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 394975 [Multi-domain] Cd Length: 47 Bit Score: 49.89 E-value: 4.70e-08

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 295 AYVASGSEQLSLAPGQLILILKKNTSGWWQGELqargKKRQKGWFPA 341
Cdd:pfam00018   5 DYTAQEPDELSFKKGDIIIVLEKSEDGWWKGRN----KGGKEGLIPS 47

C-terminal Src Homology 3 domain of LIM and SH3 domain protein 1; Lasp1 is a cytoplasmic protein that binds focal adhesion proteins and is involved in cell signaling, migration, and proliferation. It is overexpressed in several cancer cells including breast, ovarian, bladder, and liver. In cancer cells, it can be found in the nucleus; its degree of nuclear localization correlates with tumor size and poor prognosis. Lasp1 is a 36kD protein containing an N-terminal LIM domain, two nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212867 [Multi-domain] Cd Length: 59 Bit Score: 50.38 E-value: 4.76e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQG--EINGVTGLFPSNYVK 414
Cdd:cd11934     7 AVYDYNAADEDEVSFQDGDTIVNVQQIDDGWMYGtvERTGDTGMLPANYVE 57

Src homology 3 domain of ephexin-1-like SH3 domain containing Rho guanine nucleotide exchange factors; Members of this family contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and C-terminal SH3 domains. They include the Rho guanine nucleotide exchange factors ARHGEF5, ARHGEF16, ARHGEF19, ARHGEF26, ARHGEF27 (also called ephexin-1), and similar proteins, and are also called ephexins because they interact directly with ephrin A receptors. GEFs interact with Rho GTPases via their DH domains to catalyze nucleotide exchange by stabilizing the nucleotide-free GTPase intermediate. They play important roles in neuronal development. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212727 [Multi-domain] Cd Length: 55 Bit Score: 50.03 E-value: 5.33e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE--INGVTGLFPSNYV 413
Cdd:cd11793     1 QVQCVHAYTAQQPDELTLEEGDVVNVLRKMPDGWYEGErlRDGERGWFPSSYT 53

C2 domain second repeat present in Tricalbin-like proteins; 5 to 6 copies of the C2 domain are present in Tricalbin, a yeast homolog of Synaptotagmin, which is involved in membrane trafficking and sorting. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

Pssm-ID: 176017 [Multi-domain] Cd Length: 111 Bit Score: 51.83 E-value: 5.36e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 820 GKSNPYCEISMGSQS-YTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDrDQFSPDDFLGRTEIPVAKI--RTEQEs 896
Cdd:cd04052    11 GLLSPYAELYLNGKLvYTTRVKKKTNNPSWNASTEFLVTDRRKSRVTVVVKD-DRDRHDPVLGSVSISLNDLidATSVG- 88

                          90
                  ....*....|....*...
gi 1370477838 897 kgpmTRRLLLHEVPTGEV 914
Cdd:cd04052    89 ----QQWFPLSGNGQGRI 102

Src Homology 3 domain of C-terminal Src kinase; CSK is a cytoplasmic (or nonreceptor) tyr kinase containing the Src homology domains, SH3 and SH2, N-terminal to the catalytic tyr kinase domain. They negatively regulate the activity of Src kinases that are anchored to the plasma membrane. To inhibit Src kinases, CSK is translocated to the membrane via binding to specific transmembrane proteins, G-proteins, or adaptor proteins near the membrane. CSK catalyzes the tyr phosphorylation of the regulatory C-terminal tail of Src kinases, resulting in their inactivation. It is expressed in a wide variety of tissues and plays a role, as a regulator of Src, in cell proliferation, survival, and differentiation, and consequently, in cancer development and progression. In addition, CSK also shows Src-independent functions. It is a critical component in G-protein signaling, and plays a role in cytoskeletal reorganization and cell migration. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212703 [Multi-domain] Cd Length: 57 Bit Score: 49.99 E-value: 5.46e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMN-KDDPDWWQGE-INGVTGLFPSNYVK 414
Cdd:cd11769     3 ECIAKYNFNGASEEDLPFKKGDILTIVAvTKDPNWYKAKnKDGREGMIPANYVQ 56

C-terminal Src Homology 3 domain of Nebulette and LIM-nebulette (or Lasp2); Nebulette is a cardiac-specific protein that localizes to the Z-disc. It interacts with tropomyosin and is important in stabilizing actin thin filaments in cardiac muscles. Polymorphisms in the nebulette gene are associated with dilated cardiomyopathy, with some mutations resulting in severe heart failure. Nebulette is a 107kD protein that contains an N-terminal acidic region, multiple nebulin repeats, and a C-terminal SH3 domain. LIM-nebulette, also called Lasp2 (LIM and SH3 domain protein 2), is an alternatively spliced variant of nebulette. Although it shares a gene with nebulette, Lasp2 is not transcribed from a muscle-specific promoter, giving rise to its multiple tissue expression pattern with highest amounts in the brain. It can crosslink actin filaments and it affects cell spreading. Lasp2 is a 34kD protein containing an N-terminal LIM domain, three nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212868 [Multi-domain] Cd Length: 58 Bit Score: 50.00 E-value: 5.51e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEI--NGVTGLFPSNYVKM 415
Cdd:cd11935     5 AMYDYSAQDEDEVSFRDGDYIVNVQPIDEGWMYGTVqrTGRTGMLPANYIEF 56

Src homology 3 domain of Signal Transducing Adaptor Molecule 2; STAM2, also called EAST (Epidermal growth factor receptor-associated protein with SH3 and TAM domain) or Hbp (Hrs binding protein), is part of the endosomal sorting complex required for transport (ESCRT-0). It plays a role in sorting mono-ubiquinated endosomal cargo for trafficking to the lysosome for degradation. It is also involved in the regulation of exocytosis. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212896 [Multi-domain] Cd Length: 57 Bit Score: 50.02 E-value: 5.63e-08

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILV-TQKDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11963     6 ALYDFEAVEDNELTFKHGEIIIVlDDSDANWWKGENHRGVGLFPSNFV 53

Src homology 3 domains of the p47phox subunit of NADPH oxidase and similar domains; This family is composed of the tandem SH3 domains of p47phox subunit of NADPH oxidase and Nox Organizing protein 1 (NoxO1), the four SH3 domains of Tks4 (Tyr kinase substrate with four SH3 domains), the five SH3 domains of Tks5, the SH3 domain of obscurin, Myosin-I, and similar domains. Most members of this group also contain Phox homology (PX) domains, except for obscurin and Myosin-I. p47phox and NoxO1 are regulators of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) and nonphagocytic NADPH oxidase Nox1, respectively. They play roles in the activation of their respective NADPH oxidase, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Obscurin is a giant muscle protein that plays important roles in the organization and assembly of the myofibril and the sarcoplasmic reticulum. Type I myosins (Myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212790 [Multi-domain] Cd Length: 53 Bit Score: 49.94 E-value: 5.70e-08

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11856     1 SYVAIADYEAQGDDEISLQEGEVVEVLEKnDSGWWYVRKGDKEGWVPASYLEP 53

Src homology 3 domain of Src Protein Tyrosine Kinase; Src (or c-Src) is a cytoplasmic (or non-receptor) PTK and is the vertebrate homolog of the oncogenic protein (v-Src) from Rous sarcoma virus. Together with other Src subfamily proteins, it is involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. Src also play a role in regulating cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Elevated levels of Src kinase activity have been reported in a variety of human cancers. Several inhibitors of Src have been developed as anti-cancer drugs. Src is also implicated in acute inflammatory responses and osteoclast function. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212941 [Multi-domain] Cd Length: 56 Bit Score: 50.11 E-value: 5.96e-08

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE--INGVTGLFPSNYV 413
Cdd:cd12008     3 VALYDYESRTETDLSFKKGERLQIVNNTEGDWWLAHslTTGQTGYIPSNYV 53

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRB2 binds to Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, as well as to the proline-rich C-terminus of FGRF2. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212882 [Multi-domain] Cd Length: 53 Bit Score: 49.84 E-value: 6.05e-08

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11949     4 ALFDFDPQEDGELGFRRGDFIeVMDNSDPNWWKGACHGQTGMFPRNYVTP 53

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212849 [Multi-domain] Cd Length: 59 Bit Score: 49.99 E-value: 6.10e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVT--GLFPSNYVKM 415
Cdd:cd11916     6 ALYSYAPQNDDELELRDGDIVDVMEKCDDGWFVGTSRRTKqfGTFPGNYVKL 57

Src Homology 3 (SH3) domain of Inhibitor of ASPP protein (iASPP); iASPP, also called RelA-associated inhibitor (RAI), is an oncoprotein that inhibits the apoptotic transactivation potential of p53. It is upregulated in human breast cancers expressing wild-type p53, in acute leukemias regardless of the p53 mutation status, as well as in ovarian cancer where it is associated with poor patient outcome and chemoresistance. iASPP is also a binding partner and negative regulator of p65RelA, which promotes cell proliferation and inhibits apoptosis; p65RelA has the opposite effect on cell growth compared to the p53 family. It contains a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain at its C-terminal half. The SH3 domain and the ANK repeats of iASPP contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212885 [Multi-domain] Cd Length: 56 Bit Score: 49.93 E-value: 6.51e-08

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKD--DPDWWQGEINGVTGLFPSNY 412
Cdd:cd11952     3 VYALWDYSAEFPDELSFKEGDMVTVLRKDgeGTDWWWASLCGREGYVPRNY 53

Third Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212836 [Multi-domain] Cd Length: 59 Bit Score: 50.06 E-value: 6.69e-08

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNK--DDPDWWQGE-INGVTGLFPSNYV 413
Cdd:cd11903     3 VQTLYPFSSVTEEELNFEKGETMEVIEKpeNDPEWWKCKnSRGQVGLVPKNYV 55

C2 domain second repeat of Ras GTPase activating proteins (GAPs); RasGAPs suppress Ras function by enhancing the GTPase activity of Ras proteins resulting in the inactive GDP-bound form of Ras. In this way it can control cellular proliferation and differentiation. The proteins here all contain two tandem C2 domains, a Ras-GAP domain, and a pleckstrin homology (PH)-like domain. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. Members here have a type-I topology.

Pssm-ID: 176057 [Multi-domain] Cd Length: 137 Bit Score: 52.37 E-value: 7.02e-08

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gi 1370477838 803 LMVHVIEATELkACKPNGKSNPYCEISMG----SQSYTTRTIQDTLNPKWNFNcqfFIKDLYQD---------------- 862
Cdd:cd08675     1 LSVRVLECRDL-ALKSNGTCDPFARVTLNysskTDTKRTKVKKKTNNPRFDEA---FYFELTIGfsyekksfkveeedle 76

                          90       100       110
                  ....*....|....*....|....*....|.
gi 1370477838 863 --VLCLTLFDRDQFSPDDFLGRTEIPVAKIR 891
Cdd:cd08675    77 ksELRVELWHASMVSGDDFLGEVRIPLQGLQ 107

First Src Homology 3 domain of SH3 domain containing ring finger protein 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212860 Cd Length: 54 Bit Score: 49.56 E-value: 7.06e-08

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gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILV-TQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11927     5 ALYNYEGKEPGDLKFSKGDIIILrRQVDENWYHGEVNGIHGFFPTNFVQ 53

Src homology 3 domain of Signal Transducing Adaptor Molecules; STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. There are two vertebrate STAMs, STAM1 and STAM2, which may be functionally redundant; vertebrate STAMs contain ITAM motifs. They are part of the endosomal sorting complex required for transport (ESCRT-0). STAM2 deficiency in mice did not cause any obvious abnormality, while STAM1 deficiency resulted in growth retardation. Loss of both STAM1 and STAM2 in mice proved lethal, indicating that STAMs are important for embryonic development. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212754 [Multi-domain] Cd Length: 54 Bit Score: 49.77 E-value: 7.24e-08

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQ-KDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11820     5 ALYDFEAAEDNELTFKAGEIITVLDdSDPNWWKGSNHRGEGLFPANFVT 53

C2 domain in Protein Kinase C (PKC) alpha and gamma; A single C2 domain is found in PKC alpha and gamma. The PKC family of serine/threonine kinases regulates apoptosis, proliferation, migration, motility, chemo-resistance, and differentiation. There are 3 groups: group 1(alpha, betaI, beta II, gamma) which require phospholipids and calcium, group 2 (delta, epsilon, theta, eta) which do not require calcium for activation, and group 3 (xi, iota/lambda) which are atypical and can be activated in the absence of diacylglycerol and calcium. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. Members here have a type-I topology.

Pssm-ID: 175992 [Multi-domain] Cd Length: 131 Bit Score: 51.88 E-value: 7.24e-08

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gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISM-----GSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDV-LCLTLFDRDQF 874
Cdd:cd04026    13 NKLTVEVREAKNLIPMDPNGLSDPYVKLKLipdpkNETKQKTKTIKKTLNPVWNETFTFDLKPADKDRrLSIEVWDWDRT 92

                          90
                  ....*....|....*.
gi 1370477838 875 SPDDFLGRTEIPVAKI 890
Cdd:cd04026    93 TRNDFMGSLSFGVSEL 108

Fifth Src homology 3 domain (or SH3E) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212928 [Multi-domain] Cd Length: 54 Bit Score: 49.57 E-value: 7.32e-08

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gi 1370477838 141 WTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11995     9 YTAQNDDELAFSKGQIINVLNKEDpDWWKGELNGQVGLFPSNYVKL 54

C-terminal (or second) Src Homology 3 domain of the p67phox subunit of NADPH oxidase; p67phox, also called Neutrophil cytosol factor 2 (NCF-2), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox plays a regulatory role and contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. It binds, via its C-terminal SH3 domain, to a proline-rich region of p47phox and upon activation, this complex assembles with flavocytochrome b558, the Nox2-p22phox heterodimer. Concurrently, RacGTP translocates to the membrane and interacts with the TPR domain of p67phox, which leads to the activation of NADPH oxidase. The PB1 domain of p67phox binds to its partner PB1 domain in p40phox, and this facilitates the assembly of p47phox-p67phox at the membrane. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212979 [Multi-domain] Cd Length: 53 Bit Score: 49.42 E-value: 7.70e-08

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gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd12046     3 VALFSYEASQPEDLEFQKGDVILVLSKvNEDWLEGQCKGKIGIFPSAFVED 53

C-terminal Src Homology 3 domain of Nebulin; Nebulin is a giant filamentous protein (600-900 kD) that is expressed abundantly in skeletal muscle. It binds to actin thin filaments and regulates its assembly and function. Nebulin was thought to be part of a molecular ruler complex that is critical in determining the lengths of actin thin filaments in skeletal muscle since its length, which varies due to alternative splicing, correlates with the length of thin filaments in various muscle types. Recent studies indicate that nebulin regulates thin filament length by stabilizing the filaments and preventing depolymerization. Mutations in nebulin can cause nemaline myopathy, characterized by muscle weakness which can be severe and can lead to neonatal lethality. Nebulin contains an N-terminal LIM domain, many nebulin repeats/super repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212866 [Multi-domain] Cd Length: 58 Bit Score: 49.62 E-value: 7.89e-08

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gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEIN--GVTGLFPSNYVK 414
Cdd:cd11933     6 AMYDYRAADDDEVSFKDGDTIVNVQTIDEGWMYGTVQrtGKTGMLPANYVE 56

First Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212862 Cd Length: 54 Bit Score: 49.55 E-value: 8.24e-08

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gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11929     2 RAKALCNYRGHNPGDLKFNKGDVILLRRQlDENWYLGEINGVSGIFPASSVEV 54

Src Homology 3 domain of the p40phox subunit of NADPH oxidase; p40phox, also called Neutrophil cytosol factor 4 (NCF-4), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p40phox positively regulates NADPH oxidase in both phosphatidylinositol-3-phosphate (PI3P)-dependent and PI3P-independent manner. It contains an N-terminal PX domain, a central SH3 domain, and a C-terminal PB1 domain that interacts with p67phox. The SH3 domain of p40phox binds to canonical polyproline and noncanonical motifs at the C-terminus of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212802 Cd Length: 54 Bit Score: 49.41 E-value: 8.30e-08

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11869     4 ALFDFTGNSKLELNFKAGDVIFLLSRVNKDWLEGTVRGATGIFPLSFVKI 53

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing (Stac) proteins; Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. This model represents the first C-terminal SH3 domain of Stac1 and Stac3, and the single C-terminal SH3 domain of Stac2. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212767 [Multi-domain] Cd Length: 53 Bit Score: 49.42 E-value: 8.37e-08

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11833     3 VALYKFKPQENEDLEMRPGDKITLLDDSNEDWWKGKIEDRVGFFPANFV 51

Src homology 3 domain of SH3 protein interacting with Nck, 90 kDa (SPIN90); SPIN90 is also called NCK interacting protein with SH3 domain (NCKIPSD), Dia-interacting protein (DIP), 54 kDa vimentin-interacting protein (VIP54), or WASP-interacting SH3-domain protein (WISH). It is an F-actin binding protein that regulates actin polymerization and endocytosis. It associates with the Arp2/3 complex near actin filaments and determines filament localization at the leading edge of lamellipodia. SPIN90 is expressed in the early stages of neuronal differentiation and plays a role in regulating growth cone dynamics and neurite outgrowth. It also interacts with IRSp53 and regulates cell motility by playing a role in the formation of membrane protrusions. SPIN90 contains an N-terminal SH3 domain, a proline-rich domain, and a C-terminal VCA (verprolin-homology and cofilin-like acidic) domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212783 [Multi-domain] Cd Length: 53 Bit Score: 49.24 E-value: 9.16e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWW-TGSIGDRSGIFPSNYVK 267
Cdd:cd11849     2 YRALYDFKSAEPNTLSFSEGETFLLLERsNAHWWlVTNHSGETGYVPANYVK 53

First Src homology 3 domain (or SH3A) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212770 [Multi-domain] Cd Length: 55 Bit Score: 49.28 E-value: 1.01e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQEN---WWFGEVHGGRGWFPKSYV 183
Cdd:cd11836     1 KYRALYAFEARNPDEISFQPGDIIQVDESQVAepgWLAGELKGKTGWFPANYV 53

Src homology 3 domain of Nitric Oxide Synthase TRaffic INducer; Nostrin is expressed in endothelial and epithelial cells and is involved in the regulation, trafficking and targeting of endothelial NOS (eNOS). It facilitates the endocytosis of eNOS by coordinating the functions of dynamin and the Wiskott-Aldrich syndrome protein (WASP). Increased expression of Nostrin may be correlated to preeclampsia. Nostrin contains an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212757 [Multi-domain] Cd Length: 53 Bit Score: 49.26 E-value: 1.05e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 295 AYVASGSEQLSLAPGQLILILKKNTSGWWQGELqaRGKkrqKGWFPASHV 344
Cdd:cd11823     7 SYTANREDELSLQPGDIIEVHEKQDDGWWLGEL--NGK---KGIFPATYV 51

C-terminal (or second) Src homology 3 domain of VAV2 protein; VAV2 is widely expressed and functions as a guanine nucleotide exchange factor (GEF) for RhoA, RhoB and RhoG and also activates Rac1 and Cdc42. It is implicated in many cellular and physiological functions including blood pressure control, eye development, neurite outgrowth and branching, EGFR endocytosis and degradation, and cell cluster morphology, among others. It has been reported to associate with Nek3. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212910 [Multi-domain] Cd Length: 58 Bit Score: 49.24 E-value: 1.09e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNK--DDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11977     4 VARYNFAARDMRELSLREGDVVRIYSRigGDQGWWKGETNGRIGWFPSTYVE 55

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding proteins; CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes including migration, chemotaxis, apoptosis, differentiation, and progenitor cell function. They mediate the signaling of integrins at focal adhesions where they localize, and thus, regulate cell invasion and survival. Over-expression of these proteins is implicated in poor prognosis, increased metastasis, and resistance to chemotherapeutics in many cancers such as breast, lung, melanoma, and glioblastoma. CAS proteins have also been linked to the pathogenesis of inflammatory disorders, Alzheimer's, Parkinson's, and developmental defects. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. Vertebrates contain four CAS proteins: BCAR1 (or p130Cas), NEDD9 (or HEF1), EFS (or SIN), and CASS4 (or HEPL). The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212778 Cd Length: 56 Bit Score: 49.27 E-value: 1.14e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPD---WWQGEINGVTGLFPSNYVKM 415
Cdd:cd11844     4 ALYDNVAESPDELAFRRGDILTVLEQNTAGlegWWLCSLRGRQGIAPGNRLKL 56

Third Src Homology 3 domain (SH3C) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CIN85. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212990 [Multi-domain] Cd Length: 56 Bit Score: 49.13 E-value: 1.22e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 221 LYPYSSVEPGDLTFTEGEEILVTQK---DGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd12057     5 LFPYEAQNEDELTIKEGDIVTLISKdciDAGWWEGELNGRRGVFPDNFVK 54

C2 domain second repeat present in Synaptotagmin-like proteins; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 176015 [Multi-domain] Cd Length: 105 Bit Score: 50.64 E-value: 1.24e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPddfLGR 882
Cdd:cd04050     2 LFVYLDSAKNLPLAKSTKEPSPYVELTVGKTTQKSKVKERTNNPVWEEGFTFLVRNPENQELEIEVKDDKTGKS---LGS 78

                          90
                  ....*....|...
gi 1370477838 883 TEIPVAKIRTEQE 895
Cdd:cd04050    79 LTLPLSELLKEPD 91

Second Src Homology 3 domain of Nck adaptor proteins; Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212700 [Multi-domain] Cd Length: 53 Bit Score: 48.80 E-value: 1.27e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYV 183
Cdd:cd11766     1 PAVVKFNYEAQREDELSLRKGDRVLVLEKSSDgWWRGECNGQVGWFPSNYV 51

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 1 and similar proteins; This subfamily is composed of SKAP1, SKAP2, and similar proteins. SKAP1 and SKAP2 are immune cell-specific adaptor proteins that play roles in T- and B-cell adhesion, respectively, and are thus important in the migration of T- and B-cells to sites of inflammation and for movement during T-cell conjugation with antigen-presenting cells. Both SKAP1 and SKAP2 bind to ADAP (adhesion and degranulation-promoting adaptor protein), among many other binding partners. They contain a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. The SH3 domain of SKAP1 is necessary for its ability to regulate T-cell conjugation with antigen-presenting cells and the formation of LFA-1 clusters. SKAP1 binds primarily to a proline-rich region of ADAP through its SH3 domain; its degradation is regulated by ADAP. A secondary interaction occurs via the ADAP SH3 domain and the RKxxYxxY motif in SKAP1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212800 Cd Length: 53 Bit Score: 48.97 E-value: 1.28e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNK--DDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11866     4 GLWDCSGNEPDELSFKRGDLIYIISKeyDSFGWWVGELNGKVGLVPKDYL 53

Pleckstrin homology domain-containing family G member 7 pleckstrin homology (PH) domain; PLEKHG7 has a RhoGEF DH/double-homology domain in tandem with a PH domain which is involved in phospholipid binding. PLEKHG7 is proposed to functions as a guanine nucleotide exchange factor (GEF) and is involved in the regulation of Rho protein signal transduction. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

Pssm-ID: 270065 Cd Length: 128 Bit Score: 51.12 E-value: 1.28e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 666 KLLHSGKLYKTKSNK--ELHGFLFNDFLLLTYMVKQFAVSSGSEKLFS---------SKSNAQFKMYKTPIFLNEVLVK- 733
Cdd:cd13245     1 QLLHEGPLTLIESGKtlDVYLFLFDDMLLITKMKKNLKKKKSSDSENSmpsleltplIKEGGSYTVYKQPIPLDRLCLHd 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 734 -LPTDPSSD--EPVFHISHIDR------VYTLRTDNINERTAWVQKIK 772
Cdd:cd13245    81 vDPNEATANglKHAFVLVHLNRyqqvigVYTLQASSENTKQTWMSKLR 128

Src homology 3 domain of Growth Arrest Specific protein 7; GAS7 is mainly expressed in the brain and is required for neurite outgrowth. It may also play a role in the protection and migration of embryonic stem cells. Treatment-related acute myeloid leukemia (AML) has been reported resulting from mixed-lineage leukemia (MLL)-GAS7 translocations as a complication of primary cancer treatment. GAS7 contains an N-terminal SH3 domain, followed by a WW domain, and a central F-BAR domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212763 [Multi-domain] Cd Length: 52 Bit Score: 49.05 E-value: 1.28e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1370477838 300 GSEQLSLAPGQLILILKKNTSGWWQGElqargKKRQKGWFPASHV 344
Cdd:cd11829    13 HQQGLSFEAGELIRVLQAPDGGWWEGE-----KDGLRGWFPASYV 52

Variant SH3 domain;

Pssm-ID: 434066 [Multi-domain] Cd Length: 49 Bit Score: 48.77 E-value: 1.29e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDRSGIFPSNYVK 267
Cdd:pfam14604   1 ALYPYEPKDDDELSLQRGDVITVIEESEDgWWEGINTGRTGLVPANYVE 49

Src homology 3 domain of Cortactin and related proteins; This subfamily includes cortactin, Abp1 (actin-binding protein 1), hematopoietic lineage cell-specific protein 1 (HS1), and similar proteins. These proteins are involved in regulating actin dynamics through direct or indirect interaction with the Arp2/3 complex, which is required to initiate actin polymerization. They all contain at least one C-terminal SH3 domain. Cortactin and HS1 bind Arp2/3 and actin through an N-terminal region that contains an acidic domain and several copies of a repeat domain found in cortactin and HS1. Abp1 binds actin via an N-terminal actin-depolymerizing factor (ADF) homology domain. Yeast Abp1 binds Arp2/3 directly through two acidic domains. Mammalian Abp1 does not directly interact with Arp2/3; instead, it regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. The C-terminal region of these proteins acts as an adaptor or scaffold that can connect membrane trafficking and signaling proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212753 [Multi-domain] Cd Length: 54 Bit Score: 48.85 E-value: 1.41e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTG--SIGDRsGIFPSNYVK 267
Cdd:cd11819     3 KALYDYQAAEDNEISFVEGDIITqIEQIDEGWWLGvnAKGQK-GLFPANYVE 53

Fifth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212752 [Multi-domain] Cd Length: 50 Bit Score: 48.63 E-value: 1.42e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSY 182
Cdd:cd11818     1 KARALYDFTGENEDELSFKAGDIITELESiDEEWMSGELRGKSGIFPKNF 50

SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 394975 [Multi-domain] Cd Length: 47 Bit Score: 48.74 E-value: 1.49e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGR-GWFP 179
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVLEKSEdGWWKGRNKGGKeGLIP 46

C-terminal Src Homology 3 domain of the p67phox subunit of NADPH oxidase and similar proteins; This subfamily is composed of p67phox, NADPH oxidase activator 1 (Noxa1), and similar proteins. p67phox, also called Neutrophil cytosol factor 2 (NCF-2), and Noxa1 are homologs and are the cytosolic subunits of the phagocytic (Nox2) and nonphagocytic (Nox1) NADPH oxidase complexes, respectively. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox and Noxa1 play regulatory roles. p67phox contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. Noxa1 has a similar domain architecture except it is lacking the N-terminal SH3 domain. The TPR domain of both binds activated GTP-bound Rac, while the C-terminal SH3 domain of p67phox and Noxa1 binds the polyproline motif found at the C-terminus of p47phox and Noxo1, respectively. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212803 [Multi-domain] Cd Length: 53 Bit Score: 48.68 E-value: 1.55e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILV-TQKDGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11870     3 VALHRYEAQGPEDLGFREGDTIDVlSEVNEAWLEGHSDGRVGIFPKCFVVP 53

Src Homology 3 domain of Apoptosis Stimulating of p53 protein 1; ASPP1, like ASPP2, activates the apoptotic function of the p53 family of tumor suppressors (p53, p63, and p73). In addition, it functions in the cytoplasm to regulate the nuclear localization of the transcriptional cofactors YAP and TAZ by inihibiting their phosphorylation; YAP and TAZ are important regulators of cell expansion, differentiation, migration, and invasion. ASPP1 is downregulated in breast tumors expressing wild-type p53. It contains a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain at its C-terminal half. The SH3 domain and the ANK repeats of ASPP1 contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212887 [Multi-domain] Cd Length: 57 Bit Score: 48.86 E-value: 1.64e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDD---PDWWQGEINGVTGLFPSN 411
Cdd:cd11954     3 VYALWDYEAQNADELSFQEGDAITILRRKDdseTEWWWARLNDKEGYVPKN 53

Variant SH3 domain;

Pssm-ID: 434066 [Multi-domain] Cd Length: 49 Bit Score: 48.38 E-value: 1.66e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYVK 184
Cdd:pfam14604   1 ALYPYEPKDDDELSLQRGDVITVIEESEDgWWEGINTGRTGLVPANYVE 49

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing protein 3 (Stac3); Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212919 [Multi-domain] Cd Length: 53 Bit Score: 48.75 E-value: 1.69e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11986     3 VALYRFKALEKDDLDFHPGERITVIDDSNEEWWRGKIGEKTGYFPMNFI 51

Src Homology 3 domain of Cytokinesis protein 3 and similar proteins; Cytokinesis protein 3 (Cyk3 or Cyk3p) is a component of the actomyosin ring independent cytokinesis pathway in yeast. It interacts with Inn1 and facilitates its recruitment to the bud neck, thereby promoting cytokinesis. Cyk3p contains an N-terminal SH3 domain and a C-terminal transglutaminase-like domain. The Cyk3p SH3 domain binds to the C-terminal proline-rich region of Inn1. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212822 Cd Length: 53 Bit Score: 48.65 E-value: 1.77e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQ-KDGEWWTGS-IGDR-SGIFPSNYV 266
Cdd:cd11889     4 AVYSWAGETEGDLGFLEGDLIEVLSiGDGSWWSGKlRRNGaEGIFPSNFV 53

Second Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212696 [Multi-domain] Cd Length: 57 Bit Score: 48.55 E-value: 1.94e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE-----WWTGSIGDRSGIFPS 263
Cdd:cd11762     4 ALYDYEAQSDEELSFPEGAIIRILRKDDNgvddgWWEGEFNGRVGVFPS 52

Src Homology 3 domain of Sorting Nexin 9 and similar proteins; Sorting nexins (SNXs) are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. This subfamily consists of SH3 domain containing SNXs including SNX9, SNX18, SNX33, and similar proteins. SNX9 is localized to plasma membrane endocytic sites and acts primarily in clathrin-mediated endocytosis, while SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212697 [Multi-domain] Cd Length: 55 Bit Score: 48.48 E-value: 1.97e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE--WWTG--SIGDRsGIFPSNYVKP 268
Cdd:cd11763     4 ALYDFDSQPSGELSLRAGEVLTITRQDVGdgWLEGrnSRGEV-GLFPSSYVEI 55

Src Homology 3 (SH3) domain of Inhibitor of ASPP protein (iASPP); iASPP, also called RelA-associated inhibitor (RAI), is an oncoprotein that inhibits the apoptotic transactivation potential of p53. It is upregulated in human breast cancers expressing wild-type p53, in acute leukemias regardless of the p53 mutation status, as well as in ovarian cancer where it is associated with poor patient outcome and chemoresistance. iASPP is also a binding partner and negative regulator of p65RelA, which promotes cell proliferation and inhibits apoptosis; p65RelA has the opposite effect on cell growth compared to the p53 family. It contains a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain at its C-terminal half. The SH3 domain and the ANK repeats of iASPP contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212885 [Multi-domain] Cd Length: 56 Bit Score: 48.39 E-value: 2.11e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE---WWTGSIGDRSGIFPSNY 265
Cdd:cd11952     5 ALWDYSAEFPDELSFKEGDMVTVLRKDGEgtdWWWASLCGREGYVPRNY 53

First Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the first SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212715 [Multi-domain] Cd Length: 53 Bit Score: 48.49 E-value: 2.11e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11781     1 KARALYPFKAQSAKELSLKKGDIIYIRRQiDKNWYEGEHNGRVGIFPASYVEI 53

Second Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212857 Cd Length: 56 Bit Score: 48.42 E-value: 2.18e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVT--GLFPSNYVKM 415
Cdd:cd11924     2 EAVAQYTFKGDLEVELSFRKGEHICLIRKVNENWYEGRITGTGrqGIFPASYVQV 56

Src homology 3 domain of Src kinase-like Protein Tyrosine Kinases; Src subfamily members include Src, Lck, Hck, Blk, Lyn, Fgr, Fyn, Yrk, Yes, and Brk. Src (or c-Src) proteins are cytoplasmic (or non-receptor) PTKs which are anchored to the plasma membrane. They contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Brk lacks the N-terminal myristoylation sites. Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. They were identified as the first proto-oncogene products, and they regulate cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Src kinases are overexpressed in a variety of human cancers, making them attractive targets for therapy. They are also implicated in acute inflammatory responses and osteoclast function. Src, Fyn, Yes, and Yrk are widely expressed, while Blk, Lck, Hck, Fgr, Lyn, and Brk show a limited expression pattern. This subfamily also includes Drosophila Src42A, Src oncogene at 42A (also known as Dsrc41) which accumulates at sites of cell-cell or cell-matrix adhesion, and participates in Drosphila development and wound healing. It has been shown to promote tube elongation in the tracheal system, is essential for proper cell-cell matching during dorsal closure, and regulates cell-cell contacts in developing Drosophila eyes. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212779 [Multi-domain] Cd Length: 52 Bit Score: 48.35 E-value: 2.19e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWW------TGsigdRSGIFPSNY 265
Cdd:cd11845     2 YVALYDYEARTDDDLSFKKGDRLQILDDsDGDWWlarhlsTG----KEGYIPSNY 52

Src homology 3 domain of Apoptosis Stimulating of p53 proteins (ASPP); The ASPP family of proteins bind to important regulators of apoptosis (p53, Bcl-2, and RelA) and cell growth (APCL, PP1). They share similarity at their C-termini, where they harbor a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain. Vertebrates contain three members of the family: ASPP1, ASPP2, and iASPP. ASPP1 and ASPP2 activate the apoptotic function of the p53 family of tumor suppressors (p53, p63, and p73), while iASPP is an oncoprotein that specifically inhibits p53-induced apoptosis. The expression of ASPP proteins is altered in tumors; ASPP1 and ASPP2 are downregulated whereas iASPP is upregulated is some cancer types. ASPP proteins also bind and regulate protein phosphatase 1 (PP1), and this binding is competitive with p53 binding. The SH3 domain and the ANK repeats of ASPP contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212741 [Multi-domain] Cd Length: 57 Bit Score: 48.53 E-value: 2.19e-07

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDG----EWWTGSIGDRSGIFPSNY 265
Cdd:cd11807     5 ALFDYEAENGDELSFREGDELTVLRKGDddetEWWWARLNDKEGYVPRNL 54

First Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212861 Cd Length: 54 Bit Score: 48.38 E-value: 2.29e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11928     5 ALYSYEGKEPGDLKFNKGDIIILRRKvDENWYHGELNGCHGFLPASYIQ 53

Fifth Src homology 3 domain (or SH3E) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212929 [Multi-domain] Cd Length: 54 Bit Score: 48.44 E-value: 2.38e-07

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 127 GQVVenlkaqALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11996     1 CQVI------AMYDYTANNEDELSFSKGQLINVLNKDDpDWWQGEINGVTGLFPSNYVKM 54

Src homology 3 domains of the p47phox subunit of NADPH oxidase and similar domains; This family is composed of the tandem SH3 domains of p47phox subunit of NADPH oxidase and Nox Organizing protein 1 (NoxO1), the four SH3 domains of Tks4 (Tyr kinase substrate with four SH3 domains), the five SH3 domains of Tks5, the SH3 domain of obscurin, Myosin-I, and similar domains. Most members of this group also contain Phox homology (PX) domains, except for obscurin and Myosin-I. p47phox and NoxO1 are regulators of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) and nonphagocytic NADPH oxidase Nox1, respectively. They play roles in the activation of their respective NADPH oxidase, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Obscurin is a giant muscle protein that plays important roles in the organization and assembly of the myofibril and the sarcoplasmic reticulum. Type I myosins (Myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212790 [Multi-domain] Cd Length: 53 Bit Score: 48.02 E-value: 2.48e-07

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 292 VTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGElqargKKRQKGWFPASHVK 345
Cdd:cd11856     4 AIADYEAQGDDEISLQEGEVVEVLEKNDSGWWYVR-----KGDKEGWVPASYLE 52

Src homology 3 domains of Rab3-interacting molecules (RIMs) binding proteins; RIMs binding proteins (RBPs, RIM-BPs) associate with calcium channels present in photoreceptors, neurons, and hair cells; they interact simultaneously with specific calcium channel subunits, and active zone proteins, RIM1 and RIM2. RIMs are part of the matrix at the presynaptic active zone and are associated with synaptic vesicles through their interaction with the small GTPase Rab3. RIM-BPs play a role in regulating synaptic transmission by serving as adaptors and linking calcium channels with the synaptic vesicle release machinery. RIM-BPs contain three SH3 domains and two to three fibronectin III repeats. Invertebrates contain one, while vertebrates contain at least two RIM-BPs, RIM-BP1 and RIM-BP2. RIM-BP1 is also called peripheral-type benzodiazapine receptor associated protein 1 (PRAX-1). Mammals contain a third protein, RIM-BP3. RIM-BP1 and RIM-BP2 are predominantly expressed in the brain where they display overlapping but distinct expression patterns, while RIM-BP3 is almost exclusively expressed in the testis and is essential in spermiogenesis. The SH3 domains of RIM-BPs bind to the PxxP motifs of RIM1, RIM2, and L-type (alpha1D) and N-type (alpha1B) calcium channel subunits. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212785 Cd Length: 62 Bit Score: 48.47 E-value: 2.53e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 364 VIAMYDY-------AANNEDELSFSKGQLINVM-NKDDPDWWQGEINGV-TGLFPSNYVK 414
Cdd:cd11851     2 MVALYDYnpetmspNDDPEEELSFHAGDVVRVYgPMDEDGFYYGELEGGrKGLVPSNFVQ 61

Src homology 3 domain of Phospholipase C (PLC) gamma; PLC catalyzes the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG) in response to various receptors. Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma catalyzes this reaction in tyrosine kinase-dependent signaling pathways. It is activated and recruited to its substrate at the membrane. Vertebrates contain two forms of PLCgamma, PLCgamma1, which is widely expressed, and PLCgamma2, which is primarily found in haematopoietic cells. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212759 [Multi-domain] Cd Length: 54 Bit Score: 48.10 E-value: 2.68e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIIT-VLEQQENWWFGEVHGGR-GWFPKSYVK 184
Cdd:cd11825     2 VKALYDYRAQRPDELSFCKHAIITnVEKEDGGWWRGDYGGKKqKWFPANYVE 53

C-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domains (SH3c) of the related proteins, GRB2 and GRAP2, have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212884 Cd Length: 53 Bit Score: 47.87 E-value: 2.84e-07

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYV 183
Cdd:cd11951     2 VQAQYDFSAEDPSQLSFRRGDIIEVLDCPDpNWWRGRISGRVGFFPRNYV 51

Src homology 3 domain of APC-Stimulated guanine nucleotide Exchange Factor 2; ASEF2, also called Spermatogenesis-associated protein 13 (SPATA13), is a GEF that localizes with actin at the leading edge of cells and is important in cell migration and adhesion dynamics. GEFs activate small GTPases by exchanging bound GDP for free GTP. ASEF2 can activate both Rac 1 and Cdc42, but only Rac1 activation is necessary for increased cell migration and adhesion turnover. Together with APC (adenomatous polyposis coli) and Neurabin2, a scaffold protein that binds F-actin, it is involved in regulating HGF-induced cell migration. ASEF2 contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212907 Cd Length: 54 Bit Score: 48.14 E-value: 2.95e-07

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11974     5 ALWDHVTMDDQELAFKAGDVIRVLEASNKDWWWGRNEDREAWFPASFVRL 54

First Src Homology 3 domain of SH3 domain containing ring finger protein 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212860 Cd Length: 54 Bit Score: 48.02 E-value: 3.07e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11927     3 AKALYNYEGKEPGDLKFSKGDIIILRRQvDENWYHGEVNGIHGFFPTNFVQI 54

Variant SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 429575 [Multi-domain] Cd Length: 54 Bit Score: 47.98 E-value: 3.18e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKD-GEWWTGSIGDRSGIFPSNYVKP 268
Cdd:pfam07653   2 GRVIFDYVGTDKNGLTLKKGDVVKVLGKDnDGWWEGETGGRVGLVPSTAVEE 53

Src homology 3 domain of Yes Protein Tyrosine Kinase; Yes (or c-Yes) is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. c-Yes kinase is the cellular homolog of the oncogenic protein (v-Yes) encoded by the Yamaguchi 73 and Esh sarcoma viruses. It displays functional overlap with other Src subfamily members, particularly Src. It also shows some unique functions such as binding to occludins, transmembrane proteins that regulate extracellular interactions in tight junctions. Yes also associates with a number of proteins in different cell types that Src does not interact with, like JAK2 and gp130 in pre-adipocytes, and Pyk2 in treated pulmonary vein endothelial cells. Although the biological function of Yes remains unclear, it appears to have a role in regulating cell-cell interactions and vesicle trafficking in polarized cells. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212940 [Multi-domain] Cd Length: 58 Bit Score: 48.11 E-value: 3.21e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTG-SIGD-RSGIFPSNYVKPKD 270
Cdd:cd12007     3 FVALYDYEARTTEDLSFKKGERFqIINNTEGDWWEArSIATgKNGYIPSNYVAPAD 58

Src Homology 3 domain of Nephrocystin (or Nephrocystin-1); Nephrocystin contains an SH3 domain involved in signaling pathways that regulate cell adhesion and cytoskeletal organization. It is a protein that in humans is associated with juvenile nephronophthisis, an inherited kidney disease characterized by renal fibrosis that lead to chronic renal failure in children. It is localized in cell-cell junctions in renal duct cells, and is known to interact with Ack1, an activated Cdc42-associated kinase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212704 [Multi-domain] Cd Length: 54 Bit Score: 47.69 E-value: 3.24e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGE--EILVTQKDGeWWTG--SIGDRsGIFPSNYVKP 268
Cdd:cd11770     1 LYEALSDFQAEQEGDLSFKKGEvlRIISKRADG-WWLAenSKGNR-GLVPKTYLKV 54

Src Homology 3 domain of Abelson helper integration site-1 (AHI-1); AHI-1, also called Jouberin, is expressed in high levels in the brain, gonad tissues, and skeletal muscle. It is an adaptor protein that interacts with the small GTPase Rab8a and regulates it distribution and function, affecting cilium formation and vesicle transport. Mutations in the AHI-1 gene can cause Joubert syndrome, a disorder characterized by brainstem malformations, cerebellar aplasia/hypoplasia, and retinal dystrophy. AHI-1 variation is also associated with susceptibility to schizophrenia and type 2 diabetes mellitus progression. AHI-1 contains WD40 and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212746 [Multi-domain] Cd Length: 52 Bit Score: 47.89 E-value: 3.43e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGD-RSGIFPSNYV 266
Cdd:cd11812     3 VALYDYTANRSDELTIHRGDIIRVLYKDNDnWWFGSLVNgQQGYFPANYV 52

Second Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the second SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212716 [Multi-domain] Cd Length: 53 Bit Score: 47.73 E-value: 3.67e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11782     1 EARAKYNFNADTGVELSFRKGDVITLTRRvDENWYEGRIGGRQGIFPVSYVQ 52

FYVE, RhoGEF and PH domain containing/faciogenital dysplasia proteins 5 and 6, N-terminal Pleckstrin Homology (PH) domain; FGD5 regulates promotes angiogenesis of vascular endothelial growth factor (VEGF) in vascular endothelial cells, including network formation, permeability, directional movement, and proliferation. The specific function of FGD6 is unknown. In general, FGDs have a RhoGEF (DH) domain, followed by a PH domain, a FYVE domain and a C-terminal PH domain. All FGDs are guanine nucleotide exchange factors that activate the Rho GTPase Cdc42, an important regulator of membrane trafficking. The RhoGEF domain is responsible for GEF catalytic activity, while the PH domain is involved in intracellular targeting of the DH domain. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

Pssm-ID: 275424 Cd Length: 124 Bit Score: 49.96 E-value: 3.68e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 665 RKLLHSGKLYKTkSNKEL---HGFLFNDFLLLTYMVKqfavssgseklfsskSNAQFKMYKTPIFLNeVLVKLPTDPS-S 740
Cdd:cd13389    12 RKLIKEGELMKV-SRKEMqprYFFLFNDCLLYTTPVQ---------------SSGMLKLNNELPLSG-MKVKLPEDEEyS 74

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*.
gi 1370477838 741 DEpvFHISHIDRVYTLRTDNINERTAWVQKIKAASEQYidteKKKR 786
Cdd:cd13389    75 NE--FQIISTKRSFTLIASSEEERDEWVKALSRAIEEH----TKKQ 114

Src Homology 3 domain of Insulin Receptor tyrosine kinase Substrate p53, Brain-specific Angiogenesis Inhibitor 1-Associated Protein 2 (BAIAP2)-Like proteins, and similar proteins; Proteins in this family include IRSp53, BAIAP2L1, BAIAP2L2, and similar proteins. They all contain an Inverse-Bin/Amphiphysin/Rvs (I-BAR) or IMD domain in addition to the SH3 domain. IRSp53, also known as BAIAP2, is a scaffolding protein that takes part in many signaling pathways including Cdc42-induced filopodia formation, Rac-mediated lamellipodia extension, and spine morphogenesis. IRSp53 exists as multiple splicing variants that differ mainly at the C-termini. BAIAP2L1, also called IRTKS (Insulin Receptor Tyrosine Kinase Substrate), serves as a substrate for the insulin receptor and binds the small GTPase Rac. It plays a role in regulating the actin cytoskeleton and colocalizes with F-actin, cortactin, VASP, and vinculin. IRSp53 and IRTKS also mediate the recruitment of effector proteins Tir and EspFu, which regulate host cell actin reorganization, to bacterial attachment sites. BAIAP2L2 co-localizes with clathrin plaques but its function has not been determined. The SH3 domains of IRSp53 and IRTKS have been shown to bind the proline-rich C-terminus of EspFu. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212713 [Multi-domain] Cd Length: 57 Bit Score: 47.70 E-value: 3.87e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVL--EQQENWWFGE--VHGGRGWFPKSYVK 184
Cdd:cd11779     2 RVKALYPHAAGGETQLSFEEGDVITLLgpEPRDGWHYGEneRSGRRGWFPIAYTE 56

Src homology 3 domain of Ysc84p and similar fungal proteins; This family is composed of the Saccharomyces cerevisiae proteins, Ysc84p (also called LAS17-binding protein 4, Lsb4p) and Lsb3p, and similar fungal proteins. They contain an N-terminal SYLF domain (also called DUF500) and a C-terminal SH3 domain. Ysc84p localizes to actin patches and plays an important in actin polymerization during endocytosis. The N-terminal domain of both Ysc84p and Lsb3p can bind and bundle actin filaments. A study of the yeast SH3 domain interactome predicts that the SH3 domains of Lsb3p and Lsb4p may function as molecular hubs for the assembly of endocytic complexes. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212776 [Multi-domain] Cd Length: 55 Bit Score: 47.80 E-value: 3.89e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ---QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11842     1 KAVALYDFAGEQPGDLAFQKGDIITILKKsdsQNDWWTGRIGGREGIFPANYVEL 55

Third Src Homology 3 domain (SH3C) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CD2AP. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212989 [Multi-domain] Cd Length: 57 Bit Score: 47.90 E-value: 3.91e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKD-GE--WWTGSIGDRSGIFPSNYV 266
Cdd:cd12056     6 ALFHYEGTNEDELDFKEGEIILIISKDtGEpgWWKGELNGKEGVFPDNFV 55

Src homology 3 domain of Growth Arrest Specific protein 7; GAS7 is mainly expressed in the brain and is required for neurite outgrowth. It may also play a role in the protection and migration of embryonic stem cells. Treatment-related acute myeloid leukemia (AML) has been reported resulting from mixed-lineage leukemia (MLL)-GAS7 translocations as a complication of primary cancer treatment. GAS7 contains an N-terminal SH3 domain, followed by a WW domain, and a central F-BAR domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212763 [Multi-domain] Cd Length: 52 Bit Score: 47.51 E-value: 4.16e-07

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 1370477838 149 LNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYV 183
Cdd:cd11829    17 LSFEAGELIRVLQAPDGgWWEGEKDGLRGWFPASYV 52

Src Homology 3 domain of beta-Pak Interactive eXchange factor; Beta-PIX, also called Rho guanine nucleotide exchange factor 7 (ARHGEF7) or Cool (Cloned out of Library)-1, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212994 [Multi-domain] Cd Length: 54 Bit Score: 47.76 E-value: 4.18e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVT-QKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd12061     4 AKFNFQQTNEDELSFSKGDVIHVTrVEEGGWWEGTHNGRTGWFPSNYVR 52

Third Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212717 [Multi-domain] Cd Length: 55 Bit Score: 47.39 E-value: 4.55e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK--DGeWWTGS--IGDRSGIFPSNYVKP 268
Cdd:cd11783     2 YVALYPYKPQKPDELELRKGEMYTVTEKcqDG-WFKGTslRTGQSGVFPGNYVQP 55

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member, Embryonal Fyn-associated Substrate; EFS is also called HEFS, CASS3 (Cas scaffolding protein family member 3) or SIN (Src-interacting protein). It was identified based on interactions with the Src kinases, Fyn and Yes. It plays a role in thymocyte development and acts as a negative regulator of T cell proliferation. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212936 Cd Length: 62 Bit Score: 47.58 E-value: 4.56e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPD---WWQGEINGVTGLFPSNYVKM 415
Cdd:cd12003     5 ALYDNAAESPEELSFRRGDVLMVLKREHGSlpgWWLCSLHGQQGIAPANRLRL 57

Src homology 3 domain of an unknown subfamily of proteins with similarity to Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212932 [Multi-domain] Cd Length: 56 Bit Score: 47.63 E-value: 4.59e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQ-LINVMNKDDPDWWQGEIN-GVTGLFPSNYV 413
Cdd:cd11999     3 RVRAVYDYTGQEPDELSFKAGEeLLKVEDEDEQGWCKGVTDgGAVGLYPANYV 55

Third Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. The third SH3 domain of Sla1p can bind ubiquitin while retaining the ability to bind proline-rich ligands; monoubiquitination of target proteins signals internalization and sorting through the endocytic pathway. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212709 [Multi-domain] Cd Length: 57 Bit Score: 47.31 E-value: 4.67e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMN-KDDPDWWQGEI--NGVTGLFPSNYVK 414
Cdd:cd11775     2 RGKVLYDFDAQSDDELTVKEGDVVYILDdKKSKDWWMVENvsTGKEGVVPASYIE 56

Src homology 3 domain of ARHGEF9-like Rho guanine nucleotide exchange factors; Members of this family contain a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. They include the Rho guanine nucleotide exchange factors ARHGEF9, ASEF (also called ARHGEF4), ASEF2, and similar proteins. GEFs activate small GTPases by exchanging bound GDP for free GTP. ARHGEF9 specifically activates Cdc42, while both ASEF and ASEF2 can activate Rac1 and Cdc42. ARHGEF9 is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. ASEF plays a role in angiogenesis and cell migration. ASEF2 is important in cell migration and adhesion dynamics. ASEF exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli), leading to the activation of Rac1 or Cdc42. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212762 [Multi-domain] Cd Length: 53 Bit Score: 47.38 E-value: 4.68e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQ-KDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11828     3 EALWDHVTMDPEELGFKAGDVIEVLDmSDKDWWWGSIRDEEGWFPASFVR 52

Src Homology 3 domain of Cytokinesis protein 3 and similar proteins; Cytokinesis protein 3 (Cyk3 or Cyk3p) is a component of the actomyosin ring independent cytokinesis pathway in yeast. It interacts with Inn1 and facilitates its recruitment to the bud neck, thereby promoting cytokinesis. Cyk3p contains an N-terminal SH3 domain and a C-terminal transglutaminase-like domain. The Cyk3p SH3 domain binds to the C-terminal proline-rich region of Inn1. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212822 Cd Length: 53 Bit Score: 47.11 E-value: 5.15e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEI--NGVTGLFPSNYV 413
Cdd:cd11889     2 VKAVYSWAGETEGDLGFLEGDLIEVLSIGDGSWWSGKLrrNGAEGIFPSNFV 53

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase 3; GRAF3 is also called Rho GTPase activating protein 42 (ARHGAP42) or ARHGAP10-like. Though its function has not been characterized, it may be a GAP with activity towards RhoA and Cdc42, based on its similarity to GRAF and GRAF2. It contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. The SH3 domain of GRAF and GRAF2 binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212999 Cd Length: 55 Bit Score: 47.36 E-value: 5.15e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLI-NVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd12066     1 QAKAMYSCKAEHSHELSFPQGAIFsNVYPSVEPGWLKATYEGKTGLVPENYV 52

Src homology 3 domain of Signal Transducing Adaptor Molecule 1; STAM1 is part of the endosomal sorting complex required for transport (ESCRT-0) and is involved in sorting ubiquitinated cargo proteins from the endosome. It may also be involved in the regulation of IL2 and GM-CSF mediated signaling, and has been implicated in neural cell survival. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212897 [Multi-domain] Cd Length: 55 Bit Score: 47.25 E-value: 5.20e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11964     5 AIYDFEAAEDNELTFKAGDIItILDDSDPNWWKGETPQGTGLFPSNFV 52

Src Homology 3 domain of Mixed Lineage Kinase 4; MLK4 is a Serine/Threonine Kinase (STK), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. The specific function of MLK4 is yet to be determined. Mutations in the kinase domain of MLK4 have been detected in colorectal cancers. MLK4 contains an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212991 [Multi-domain] Cd Length: 58 Bit Score: 47.24 E-value: 5.22e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKDGE------WWTGSIGDRSGIFPSNYVKP 268
Cdd:cd12058     2 WTALYDYEASGEDELSLRRGDVVEVLSQDAAvsgddgWWAGKIRHRLGIFPANYVTR 58

Second Src Homology 3 domain of Nck adaptor proteins; Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212700 [Multi-domain] Cd Length: 53 Bit Score: 47.26 E-value: 5.22e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 289 IAQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHV 344
Cdd:cd11766     1 PAVVKFNYEAQREDELSLRKGDRVLVLEKSSDGWWRGECNG-----QVGWFPSNYV 51

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 2; ASAP2 is also called DDEF2 (Development and Differentiation Enhancing Factor 2), AMAP2, centaurin beta-3, or PAG3. It mediates the functions of Arf GTPases vial dual mechanisms: it exhibits GTPase activating protein (GAP) activity towards class I (Arf1) and II (Arf5) Arfs; and it binds class III Arfs (GTP-Arf6) stably without GAP activity. It binds paxillin and is implicated in Fcgamma receptor-mediated phagocytosis in macrophages and in cell migration. ASAP2 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212899 Cd Length: 56 Bit Score: 47.26 E-value: 5.30e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVT-QKDGEWWTGSI-GD--RSGIFPSNYV 266
Cdd:cd11966     4 ALYNCVADNPDELTFSEGEIIIVDgEEDKEWWIGHIdGEptRRGAFPVSFV 54

Src homology 3 domain of Cortactin and related proteins; This subfamily includes cortactin, Abp1 (actin-binding protein 1), hematopoietic lineage cell-specific protein 1 (HS1), and similar proteins. These proteins are involved in regulating actin dynamics through direct or indirect interaction with the Arp2/3 complex, which is required to initiate actin polymerization. They all contain at least one C-terminal SH3 domain. Cortactin and HS1 bind Arp2/3 and actin through an N-terminal region that contains an acidic domain and several copies of a repeat domain found in cortactin and HS1. Abp1 binds actin via an N-terminal actin-depolymerizing factor (ADF) homology domain. Yeast Abp1 binds Arp2/3 directly through two acidic domains. Mammalian Abp1 does not directly interact with Arp2/3; instead, it regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. The C-terminal region of these proteins acts as an adaptor or scaffold that can connect membrane trafficking and signaling proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212753 [Multi-domain] Cd Length: 54 Bit Score: 47.31 E-value: 5.33e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGG-RGWFPKSYVKI 185
Cdd:cd11819     2 AKALYDYQAAEDNEISFVEGDIITQIEQiDEGWWLGVNAKGqKGLFPANYVEL 54

Fifth Src homology 3 domain (or SH3E) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212928 [Multi-domain] Cd Length: 54 Bit Score: 47.26 E-value: 5.52e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11995     2 QVIGMYDYTAQNDDELAFSKGQIInVLNKEDPDWWKGELNGQVGLFPSNYVK 53

First Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212862 Cd Length: 54 Bit Score: 47.24 E-value: 5.52e-07

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILV-TQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11929     5 ALCNYRGHNPGDLKFNKGDVILLrRQLDENWYLGEINGVSGIFPASSVE 53

Src Homology 3 domain of Tec-like Protein Tyrosine Kinases; The Tec (Tyrosine kinase expressed in hepatocellular carcinoma) subfamily is composed of Tec, Btk, Bmx (Etk), Itk (Tsk, Emt), Rlk (Txk), and similar proteins. They are cytoplasmic (or nonreceptor) tyr kinases containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. Most Tec subfamily members (except Rlk) also contain an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation. In addition, some members contain the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. Tec kinases are expressed mainly by haematopoietic cells, although Tec and Bmx are also found in endothelial cells. B-cells express Btk and Tec, while T-cells express Itk, Txk, and Tec. Collectively, Tec kinases are expressed in a variety of myeloid cells such as mast cells, platelets, macrophages, and dendritic cells. Each Tec kinase shows a distinct cell-type pattern of expression. The function of Tec kinases in lymphoid cells have been studied extensively. They play important roles in the development, differentiation, maturation, regulation, survival, and function of B-cells and T-cells. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212702 [Multi-domain] Cd Length: 54 Bit Score: 47.27 E-value: 5.54e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGD-RSGIFPSNYVKP 268
Cdd:cd11768     3 VALYDFQPIEPGDLPLEKGEEYVVLDDSNEhWWRARDKNgNEGYIPSNYVTE 54

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase; GRAF, also called Rho GTPase activating protein 26 (ARHGAP26), Oligophrenin-1-like (OPHN1L) or GRAF1, is a GAP with activity towards RhoA and Cdc42 and is only weakly active towards Rac1. It influences Rho-mediated cytoskeletal rearrangements and binds focal adhesion kinase (FAK), which is a critical component of integrin signaling. It is essential for the major clathrin-independent endocytic pathway mediated by pleiomorphic membranes. GRAF contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. The SH3 domain of GRAF binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212997 Cd Length: 56 Bit Score: 47.42 E-value: 5.62e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLI-NVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12064     5 ALYACKAEHDSELSFTAGTVFdNVHPSQEPGWLEGTLNGKTGLIPENYVE 54

Variant SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 429575 [Multi-domain] Cd Length: 54 Bit Score: 47.21 E-value: 5.67e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELqargkKRQKGWFPASHVKLL 347
Cdd:pfam07653   2 GRVIFDYVGTDKNGLTLKKGDVVKVLGKDNDGWWEGET-----GGRVGLVPSTAVEEI 54

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 1; SKAP1, also called SKAP55 (Src kinase-associated protein of 55kDa), is an immune cell-specific adaptor protein that plays an important role in T-cell adhesion, migration, and integrin clustering. It is expressed exclusively in T-lymphocytes, mast cells, and macrophages. Binding partners include ADAP (adhesion and degranulation-promoting adaptor protein), Fyn, Riam, RapL, and RasGRP. It contains a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. The SH3 domain of SKAP1 is necessary for its ability to regulate T-cell conjugation with antigen-presenting cells and the formation of LFA-1 clusters. SKAP1 binds primarily to a proline-rich region of ADAP through its SH3 domain; its degradation is regulated by ADAP. A secondary interaction occurs via the ADAP SH3 domain and the RKxxYxxY motif in SKAP1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212977 Cd Length: 53 Bit Score: 47.16 E-value: 6.04e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDP--DWWQGEINGVTGLFPSNYV 413
Cdd:cd12044     4 GLWDCFGDNPDELSFQRGDLIYILSKEYNmyGWWVGELNGIVGIVPKDYL 53

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212850 [Multi-domain] Cd Length: 61 Bit Score: 47.29 E-value: 6.24e-07

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVT--GLFPSNYVK 414
Cdd:cd11917     9 ALYNYMPRNEDELELREGDVIDVMEKCDDGWFVGTSRRTKffGTFPGNYVK 59

Src homology 3 domain of SH3 domain containing Ysc84-like 1 (SH3YL1) protein; SH3YL1 localizes to the plasma membrane and is required for dorsal ruffle formation. It binds phosphoinositides (PIs) with high affinity through its N-terminal SYLF domain (also called DUF500). In addition, SH3YL1 contains a C-terminal SH3 domain which has been reported to bind to N-WASP, dynamin 2, and SHIP2 (a PI 5-phosphatase). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212775 Cd Length: 54 Bit Score: 47.00 E-value: 6.45e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVL---EQQENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11841     2 VTALYSFEGQQPCDLSFQAGDRITVLtrtDSQFDWWEGRLRGRVGIFPANYVS 54

Third Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212718 Cd Length: 55 Bit Score: 47.08 E-value: 6.72e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE--INGVTGLFPSNYV 413
Cdd:cd11784     3 VALHSYSAHRPEELELQKGEGVRVLGKFQEGWLRGLslVTGRVGIFPSNYV 53

Src Homology 3 domain of Nephrocystin (or Nephrocystin-1); Nephrocystin contains an SH3 domain involved in signaling pathways that regulate cell adhesion and cytoskeletal organization. It is a protein that in humans is associated with juvenile nephronophthisis, an inherited kidney disease characterized by renal fibrosis that lead to chronic renal failure in children. It is localized in cell-cell junctions in renal duct cells, and is known to interact with Ack1, an activated Cdc42-associated kinase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212704 [Multi-domain] Cd Length: 54 Bit Score: 46.92 E-value: 7.16e-07

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE-INGVTGLFPSNYVKM 415
Cdd:cd11770     2 YEALSDFQAEQEGDLSFKKGEVLRIISKRADGWWLAEnSKGNRGLVPKTYLKV 54

Src homology 3 domain of Growth Arrest Specific protein 7; GAS7 is mainly expressed in the brain and is required for neurite outgrowth. It may also play a role in the protection and migration of embryonic stem cells. Treatment-related acute myeloid leukemia (AML) has been reported resulting from mixed-lineage leukemia (MLL)-GAS7 translocations as a complication of primary cancer treatment. GAS7 contains an N-terminal SH3 domain, followed by a WW domain, and a central F-BAR domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212763 [Multi-domain] Cd Length: 52 Bit Score: 46.74 E-value: 7.21e-07

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 366 AMYDYAANNEDE-LSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11829     4 TLYAFTGEQHQQgLSFEAGELIRVLQAPDGGWWEGEKDGLRGWFPASYV 52

Src Homology 3 domain of alpha-Pak Interactive eXchange factor; Alpha-PIX, also called Rho guanine nucleotide exchange factor 6 (ARHGEF6) or Cool (Cloned out of Library)-2, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and is localized in dendritic spines where it regulates spine morphogenesis. It controls dendritic length and spine density in the hippocampus. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212993 Cd Length: 58 Bit Score: 46.92 E-value: 7.48e-07

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQ-KDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd12060     6 ARFNFKQTNEDELSVCKGDIIYVTRvEEGGWWEGTLNGKTGWFPSNYVR 54

Second Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the second SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212721 [Multi-domain] Cd Length: 53 Bit Score: 46.56 E-value: 8.37e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDE---LSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNY 412
Cdd:cd11787     1 QCKALYDFEMKDEDEkdcLTFKKGDVITVIRRVDENWAEGRLGDKIGIFPISF 53

Second Src Homology 3 domain of FCH and double SH3 domains protein 1; FCHSD1 has a domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. It has only been characterized in silico and its function is unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212828 Cd Length: 58 Bit Score: 46.88 E-value: 8.37e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD----DPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11895     4 ALYSYTGQSPEELSFPEGALIRLLPRAqdgvDDGFWRGEFGGRVGVFPSLLVE 56

Third Src homology 3 domain of Rab3-interacting molecules (RIMs) binding proteins; RIMs binding proteins (RBPs, RIM-BPs) associate with calcium channels present in photoreceptors, neurons, and hair cells; they interact simultaneously with specific calcium channel subunits, and active zone proteins, RIM1 and RIM2. RIMs are part of the matrix at the presynaptic active zone and are associated with synaptic vesicles through their interaction with the small GTPase Rab3. RIM-BPs play a role in regulating synaptic transmission by serving as adaptors and linking calcium channels with the synaptic vesicle release machinery. RIM-BPs contain three SH3 domains and two to three fibronectin III repeats. Invertebrates contain one, while vertebrates contain at least two RIM-BPs, RIM-BP1 and RIM-BP2. RIM-BP1 is also called peripheral-type benzodiazapine receptor associated protein 1 (PRAX-1). Mammals contain a third protein, RIM-BP3. RIM-BP1 and RIM-BP2 are predominantly expressed in the brain where they display overlapping but distinct expression patterns, while RIM-BP3 is almost exclusively expressed in the testis and is essential in spermiogenesis. The SH3 domains of RIM-BPs bind to the PxxP motifs of RIM1, RIM2, and L-type (alpha1D) and N-type (alpha1B) calcium channel subunits. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212946 Cd Length: 61 Bit Score: 46.99 E-value: 8.77e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 363 QVIAMYDYAAN----NED---ELSFSKGQLINVMNKDDPD-WWQGEINGVTGLFPSNYVK 414
Cdd:cd12013     1 RMVALFDYDPResspNVDaevELSFRAGDIITVFGEMDEDgFYYGELNGQRGLVPSNFLE 60

First Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212852 [Multi-domain] Cd Length: 55 Bit Score: 46.49 E-value: 9.27e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11919     2 PARAKFDFKAQTLKELPLQKGDIVYIYKQIDQNWYEGEHHGRVGIFPRSYIEL 54

Src homology 3 domain of Brk (Breast tumor kinase) Protein Tyrosine Kinase (PTK), also called PTK6; Brk is a cytoplasmic (or non-receptor) PTK with limited homology to Src kinases. It has been found to be overexpressed in a majority of breast tumors. It plays roles in normal cell differentiation, proliferation, survival, migration, and cell cycle progression. Brk substrates include RNA-binding proteins (SLM-1/2, Sam68), transcription factors (STAT3/5), and signaling molecules (Akt, paxillin, IRS-4). Src kinases in general contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr; they are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Brk lacks the N-terminal myristoylation site. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212781 [Multi-domain] Cd Length: 58 Bit Score: 46.78 E-value: 9.34e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKDGEWWTGSIGDRS------GIFPSNYV 266
Cdd:cd11847     2 YKALWDFKARGDEELSFQAGDQFRIAERSGDWWTALKLDRAggvvaqGFVPNNYL 56

Src Homology 3 domain of Membrane Protein, Palmitoylated 7 (or MAGUK p55 subfamily member 7); MPP7 is a scaffolding protein that binds to DLG1 and promotes tight junction formation and epithelial cell polarity. Mutations in the MPP7 gene may be associated with the pathogenesis of diabetes and extreme bone mineral density. It is one of seven vertebrate homologs of the Drosophila Stardust protein, which is required in establishing cell polarity, and it contains two L27 domains followed by the core of three domains characteristic of MAGUK (membrane-associated guanylate kinase) proteins: PDZ, SH3, and guanylate kinase (GuK). The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212966 Cd Length: 61 Bit Score: 46.94 E-value: 9.51e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 364 VIAMYDYAAN-------NEDELSFSKGQLINVMNKDDPDWWQ----GEINGVTGLFPSNY 412
Cdd:cd12033     2 IKALFDYNPNedkaipcKEAGLSFKKGDILQIMSQDDATWWQakheGDANPRAGLIPSKH 61

Src homology 3 domain of Abl Interactor proteins; Abl interactor (Abi) proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. They localize to sites of actin polymerization in epithelial adherens junction and immune synapses, as well as to the leading edge of lamellipodia. Vertebrates contain two Abi proteins, Abi1 and Abi2. Abi1 displays a wide expression pattern while Abi2 is highly expressed in the eye and brain. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212760 [Multi-domain] Cd Length: 52 Bit Score: 46.55 E-value: 9.83e-07

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYV 183
Cdd:cd11826     1 KVVALYDYTADKDDELSFQEGDIIYVTKKNDDgWYEGVLNGVTGLFPGNYV 51

Second Src Homology 3 domain (SH3B) of CD2-associated protein and similar proteins; This subfamily is composed of the second SH3 domain (SH3B) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3B of both proteins have been shown to bind to Cbl. In the case of CD2AP, its SH3B binds to Cbl at a site distinct from the c-Cbl/SH3A binding site. The CIN85 SH3B also binds ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212807 [Multi-domain] Cd Length: 53 Bit Score: 46.56 E-value: 1.02e-06

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGE--EILVTQKDGeWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11874     4 VLFSYTPQNEDELELKVGDtiEVLGEVEEG-WWEGKLNGKVGVFPSNFVK 52

Second Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212835 [Multi-domain] Cd Length: 55 Bit Score: 46.54 E-value: 1.03e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHV 344
Cdd:cd11902     3 AFVKFAYVAEREDELSLVKGSRVTVMEKCSDGWWRGSYNG-----QIGWFPSNYV 52

Src Homology 3 domain of SH3 domain-containing protein 21 (SH3D21) and similar proteins; N-terminal SH3 domain of the uncharacterized protein SH3 domain-containing protein 21, and similar uncharacterized domains, it belongs to the CD2AP-like_3 subfamily of proteins. The CD2AP-like_3 subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213018 [Multi-domain] Cd Length: 55 Bit Score: 46.30 E-value: 1.04e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQ---ENWWFGEVHGGRGWFPKSYV 183
Cdd:cd12142     1 YCRVLFDYNPVAPDELALKKGDVIEVISKEtedEGWWEGELNGRRGFFPDNFV 53

Src Homology 3 domain of Membrane Protein, Palmitoylated 1 (or MAGUK p55 subfamily member 1); MPP1, also called 55 kDa erythrocyte membrane protein (p55), is a ubiquitously-expressed scaffolding protein that plays roles in regulating neutrophil polarity, cell shape, hair cell development, and neural development and patterning of the retina. It was originally identified as an erythrocyte protein that stabilizes the actin cytoskeleton to the plasma membrane by forming a complex with 4.1R protein and glycophorin C. MPP1 is one of seven vertebrate homologs of the Drosophila Stardust protein, which is required in establishing cell polarity, and it contains the three domains characteristic of MAGUK (membrane-associated guanylate kinase) proteins: PDZ, SH3, and guanylate kinase (GuK). In addition, it also contains the Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213013 Cd Length: 62 Bit Score: 46.49 E-value: 1.06e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 368 YDYAANN-----EDELSFSKGQLINVMNKDDPDWWQGEINGV----TGLFPS 410
Cdd:cd12080     8 YDPKKDNlipckEAGLKFQTGDIIQIINKDDSNWWQGRVEGSgeesAGLIPS 59

Third Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212718 Cd Length: 55 Bit Score: 46.31 E-value: 1.07e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKDGEWW-------TGsigdRSGIFPSNYVKP 268
Cdd:cd11784     2 CVALHSYSAHRPEELELQKGEGVRVLGKFQEGWlrglslvTG----RVGIFPSNYVSP 55

Src homology 3 domain of ARHGEF9-like Rho guanine nucleotide exchange factors; Members of this family contain a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. They include the Rho guanine nucleotide exchange factors ARHGEF9, ASEF (also called ARHGEF4), ASEF2, and similar proteins. GEFs activate small GTPases by exchanging bound GDP for free GTP. ARHGEF9 specifically activates Cdc42, while both ASEF and ASEF2 can activate Rac1 and Cdc42. ARHGEF9 is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. ASEF plays a role in angiogenesis and cell migration. ASEF2 is important in cell migration and adhesion dynamics. ASEF exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli), leading to the activation of Rac1 or Cdc42. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212762 [Multi-domain] Cd Length: 53 Bit Score: 46.22 E-value: 1.09e-06

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11828     1 LAEALWDHVTMDPEELGFKAGDVIEVLDMSDkDWWWGSIRDEEGWFPASFVRL 53

First Src Homology 3 domain (SH3A) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CIN85; SH3A binds to internal proline-rich motifs within the proline-rich region. This intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. SH3A has also been shown to bind ubiquitin and to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic end of the cell adhesion protein CD2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212985 [Multi-domain] Cd Length: 53 Bit Score: 46.43 E-value: 1.18e-06

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd12052     1 EAIVEFDYKAQHEDELTITVGDIITkIKKDDGGWWEGEIKGRRGLFPDNFVR 52

Third (or C-terminal) Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212851 [Multi-domain] Cd Length: 58 Bit Score: 46.49 E-value: 1.19e-06

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQG--EINGVTGLFPSNYV 413
Cdd:cd11918     6 AVYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 55

C-terminal Src Homology 3 domain of NADPH oxidase activator 1; Noxa1 is a homolog of p67phox and is a cytosolic subunit of the nonphagocytic NADPH oxidase complex Nox1, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Noxa1 is co-expressed with Nox1 in colon, stomach, uterus, prostate, and vascular smooth muscle cells, consistent with its regulatory role. It does not interact with p40phox, unlike p67phox, making Nox1 activity independent of p40phox, unlike Nox2. Noxa1 contains TPR, PB1, and C-terminal SH3 domains, but lacks the central SH3 domain that is present in p67phox. The TPR domain binds activated GTP-bound Rac. The C-terminal SH3 domain binds the polyproline motif found at the C-terminus of Noxo1, a homolog of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212980 Cd Length: 53 Bit Score: 46.35 E-value: 1.26e-06

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd12047     3 VAQHDYSAQGPEDLEFSQGDTIdILSEVNQEWLEGHCDGRIGIFPKCFAVR 53

Src Homology 3 domain of Bruton's tyrosine kinase; BTK is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation, and the Tec homology (TH) domain with proline-rich and zinc-binding regions. Btk is expressed in B-cells, and a variety of myeloid cells including mast cells, platelets, neutrophils, and dendrictic cells. It interacts with a variety of partners, from cytosolic proteins to nuclear transcription factors, suggesting a diversity of functions. Stimulation of a diverse array of cell surface receptors, including antigen engagement of the B-cell receptor (BCR), leads to PH-mediated membrane translocation of Btk and subsequent phosphorylation by Src kinase and activation. Btk plays an important role in the life cycle of B-cells including their development, differentiation, proliferation, survival, and apoptosis. Mutations in Btk cause the primary immunodeficiency disease, X-linked agammaglobulinaemia (XLA) in humans. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212839 [Multi-domain] Cd Length: 55 Bit Score: 45.97 E-value: 1.34e-06

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQG-EINGVTGLFPSNYV 413
Cdd:cd11906     3 VVALYDYTPMNAQDLQLRKGEEYVILEESNLPWWRArDKNGREGYIPSNYV 53

Fifth Src homology 3 domain (or SH3E) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212929 [Multi-domain] Cd Length: 54 Bit Score: 46.13 E-value: 1.40e-06

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHVKL 346
Cdd:cd11996     9 YTANNEDELSFSKGQLINVLNKDDPDWWQGEING-----VTGLFPSNYVKM 54

Second Src homology 3 domain (or SH3B) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212922 [Multi-domain] Cd Length: 52 Bit Score: 45.86 E-value: 1.42e-06

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPdWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11989     1 QAQALYPWRAKKDNHLNFNKNDVITVLEQQDM-WWFGEVQGQKGWFPKSYVKL 52

Src homology 3 domain of Myosins Ie, If, and similar proteins; Myosins Ie (MyoIe) and If (MyoIf) are nonmuscle, unconventional, long tailed, class I myosins containing an N-terminal motor domain and a myosin tail with TH1, TH2, and SH3 domains. MyoIe interacts with the endocytic proteins, dynamin and synaptojanin-1, through its SH3 domain; it may play a role in clathrin-dependent endocytosis. In the kidney, MyoIe is critical for podocyte function and normal glomerular filtration. Mutations in MyoIe is associated with focal segmental glomerulosclerosis, a disease characterized by massive proteinuria and progression to end-stage kidney disease. MyoIf is predominantly expressed in the immune system; it plays a role in immune cell motility and innate immunity. Mutations in MyoIf may be associated with the loss of hearing. The MyoIf gene has also been found to be fused to the MLL (Mixed lineage leukemia) gene in infant acute myeloid leukemias (AML). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212761 [Multi-domain] Cd Length: 53 Bit Score: 45.87 E-value: 1.43e-06

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 295 AYVASGSEQLSLAPGQLILILKKNTSGWWQGELqaRGKkrqKGWFPASHV 344
Cdd:cd11827     7 AYDAQDTDELSFNEGDIIEILKEDPSGWWTGRL--RGK---EGLFPGNYV 51

Second or C-terminal Src homology 3 domain of NADPH oxidase (Nox) Organizing protein 1; Nox Organizing protein 1 (NoxO1) is a critical regulator of enzyme kinetics of the nonphagocytic NADPH oxidase Nox1, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Nox1 is expressed in colon, stomach, uterus, prostate, and vascular smooth muscle cells. NoxO1 is involved in targeting activator subunits (such as NoxA1) to Nox1. It is co-localized with Nox1 in the membranes of resting cells and directs the subcellular localization of Nox1. NoxO1 contains an N-terminal Phox homology (PX) domain, tandem SH3 domains (N-SH3 and C-SH3), and a C-terminal proline-rich region (PRR). This model characterizes the second SH3 domain (or C-SH3) of NoxO1. The tandem SH3 domains of NoxO1 interact with the PRR of p22phox, which also complexes with Nox1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212957 Cd Length: 53 Bit Score: 45.79 E-value: 1.73e-06

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12024     4 ATRAYEAQKEDELSVPAGVVVEVLQKSDNGWWLIRYNGRAGYVPSMYLQ 52

C-terminal (or second) Src homology 3 domain of VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and it plays an important role in the development and activation of B and T cells. It is activated by tyrosine phosphorylation to function as a guanine nucleotide exchange factor (GEF) for Rho GTPases following cell surface receptor activation, triggering various effects such as cytoskeletal reorganization, transcription regulation, cell cycle progression, and calcium mobilization. It also serves as a scaffold protein and has been shown to interact with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76, and Syk, among others. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The C-terminal SH3 domain of Vav1 interacts with a wide variety of proteins including cytoskeletal regulators (zyxin), RNA-binding proteins (Sam68), transcriptional regulators, viral proteins, and dynamin 2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212909 [Multi-domain] Cd Length: 54 Bit Score: 45.71 E-value: 1.73e-06

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQ--QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11976     2 AKARYDFCARDRSELSLKEGDIIKILNKkgQQGWWRGEIYGRVGWFPANYVE 53

Src Homology 3 domain of beta-Pak Interactive eXchange factor; Beta-PIX, also called Rho guanine nucleotide exchange factor 7 (ARHGEF7) or Cool (Cloned out of Library)-1, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212994 [Multi-domain] Cd Length: 54 Bit Score: 45.83 E-value: 1.75e-06

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                  ....*....|....*....|....*....|....*....|
gi 1370477838 146 DNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYVK 184
Cdd:cd12061    13 EDELSFSKGDVIHVTRVEEGgWWEGTHNGRTGWFPSNYVR 52

Src homology 3 domain of Cortactin; Cortactin was originally identified as a substrate of Src kinase. It is an actin regulatory protein that binds to the Arp2/3 complex and stabilizes branched actin filaments. It is involved in cellular processes that affect cell motility, adhesion, migration, endocytosis, and invasion. It is expressed ubiquitously except in hematopoietic cells, where the homolog hematopoietic lineage cell-specific 1 (HS1) is expressed instead. Cortactin contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region interacts with the Arp2/3 complex and F-actin, and is crucial in regulating branched actin assembly. Cortactin also serves as a scaffold and provides a bridge to the actin cytoskeleton for membrane trafficking and signaling proteins that bind to its SH3 domain. Binding partners for the SH3 domain of cortactin include dynamin2, N-WASp, MIM, FGD1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212892 [Multi-domain] Cd Length: 53 Bit Score: 45.87 E-value: 1.78e-06

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11959     2 AVALYDYQAADDDEISFDPDDIITNIEMiDEGWWRGVCRGKYGLFPANYVEL 53

C2 domain second repeat present in Synaptotagmin; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. There are several classes of Synaptotagmins. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 175975 [Multi-domain] Cd Length: 134 Bit Score: 47.96 E-value: 1.86e-06

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gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISM---GSQSYT--TRTIQDTLNPKWnfNCQFFIK----DLYQDVLCLTLFDR 871
Cdd:cd00276    14 ERLTVVVLKARNLPPSDGKGLSDPYVKVSLlqgGKKLKKkkTSVKKGTLNPVF--NEAFSFDvpaeQLEEVSLVITVVDK 91

                          90       100
                  ....*....|....*....|....
gi 1370477838 872 DQFSPDDFLGRTEIPVAKIRTEQE 895
Cdd:cd00276    92 DSVGRNEVIGQVVLGPDSGGEELE 115

Src homology 3 domain of Phospholipase C (PLC) gamma; PLC catalyzes the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG) in response to various receptors. Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma catalyzes this reaction in tyrosine kinase-dependent signaling pathways. It is activated and recruited to its substrate at the membrane. Vertebrates contain two forms of PLCgamma, PLCgamma1, which is widely expressed, and PLCgamma2, which is primarily found in haematopoietic cells. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212759 [Multi-domain] Cd Length: 54 Bit Score: 45.79 E-value: 1.87e-06

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGDR-SGIFPSNYVK 267
Cdd:cd11825     4 ALYDYRAQRPDELSFCKHAIITnVEKEDGGWWRGDYGGKkQKWFPANYVE 53

Src homology 3 domain of ARHGEF9-like Rho guanine nucleotide exchange factors; Members of this family contain a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. They include the Rho guanine nucleotide exchange factors ARHGEF9, ASEF (also called ARHGEF4), ASEF2, and similar proteins. GEFs activate small GTPases by exchanging bound GDP for free GTP. ARHGEF9 specifically activates Cdc42, while both ASEF and ASEF2 can activate Rac1 and Cdc42. ARHGEF9 is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. ASEF plays a role in angiogenesis and cell migration. ASEF2 is important in cell migration and adhesion dynamics. ASEF exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli), leading to the activation of Rac1 or Cdc42. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212762 [Multi-domain] Cd Length: 53 Bit Score: 45.84 E-value: 1.88e-06

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHVKL 346
Cdd:cd11828     8 HVTMDPEELGFKAGDVIEVLDMSDKDWWWGSIRDE-----EGWFPASFVRL 53

Src homology 3 domain of Phospholipase C (PLC) gamma 2; PLCgamma2 is primarily expressed in haematopoietic cells, specifically in B cells. It is activated by tyrosine phosphorylation by B cell receptor (BCR) kinases and is recruited to the plasma membrane where its substrate is located. It is required in pre-BCR signaling and in the maturation of B cells. PLCs catalyze the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG). Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212902 Cd Length: 55 Bit Score: 45.60 E-value: 1.93e-06

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGDR-SGIFPSNYVK 267
Cdd:cd11969     4 ALYDYRAKRSDELSFCKGALIHnVSKETGGWWKGDYGGKvQHYFPSNYVE 53

First Src Homology 3 domain of Bzz1 and similar domains; Bzz1 (or Bzz1p) is a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Together with other proteins, it induces membrane scission in yeast. Bzz1 contains an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a central coiled-coil, and two C-terminal SH3 domains. This model represents the first C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212845 [Multi-domain] Cd Length: 55 Bit Score: 45.68 E-value: 1.95e-06

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQgEI---NGVTGLFPSNYVKM 415
Cdd:cd11912     4 VLYDYTASGDDEVSISEGEEVTVLEPDDGSGWT-KVrngSGEEGLVPTSYIEI 55

First Src homology 3 domain (or SH3A) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212920 [Multi-domain] Cd Length: 55 Bit Score: 45.38 E-value: 2.23e-06

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD--DPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11987     4 ALYPFEARSHDEITIQPGDIVMVDESQtgEPGWLGGELKGKTGWFPANYAE 54

Src homology 3 domain of SH3 and multiple ankyrin repeat domains protein 1; Shank1, also called SSTRIP (Somatostatin receptor-interacting protein), is a brain-specific protein that plays a role in the construction of postsynaptic density (PSD) and the maturation of dendritic spines. Mice deficient in Shank1 show altered PSD composition, thinner PSDs, smaller dendritic spines, and weaker basal synaptic transmission, although synaptic plasticity is normal. They show increased anxiety and impaired fear memory, but also show better spatial learning. Shank proteins carry scaffolding functions through multiple sites of protein-protein interaction in its domain architecture, including ankyrin (ANK) repeats, a long proline rich region, as well as SH3, PDZ, and SAM domains. The SH3 domain of Shank binds GRIP, a scaffold protein that binds AMPA receptors and Eph receptors/ligands. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212915 [Multi-domain] Cd Length: 52 Bit Score: 45.39 E-value: 2.24e-06

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11982     4 MAVKPYQSQAEGEISLSKGEKIKVLSVGEGGFWEGQVKGRVGWFPSDCV 52

C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing protein 2 (Stac2); Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac2 contains a single SH3 domain at the C-terminus unlike Stac1 and Stac3, which contain two C-terminal SH3 domains. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212918 Cd Length: 53 Bit Score: 45.32 E-value: 2.29e-06

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gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11985     3 VALYKFLPQENNDLPLQPGDRVMVVDDSNEDWWKGKSGDRVGFFPANFVQ 52

Src homology 3 domains of the p47phox subunit of NADPH oxidase and similar domains; This family is composed of the tandem SH3 domains of p47phox subunit of NADPH oxidase and Nox Organizing protein 1 (NoxO1), the four SH3 domains of Tks4 (Tyr kinase substrate with four SH3 domains), the five SH3 domains of Tks5, the SH3 domain of obscurin, Myosin-I, and similar domains. Most members of this group also contain Phox homology (PX) domains, except for obscurin and Myosin-I. p47phox and NoxO1 are regulators of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) and nonphagocytic NADPH oxidase Nox1, respectively. They play roles in the activation of their respective NADPH oxidase, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Obscurin is a giant muscle protein that plays important roles in the organization and assembly of the myofibril and the sarcoplasmic reticulum. Type I myosins (Myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212790 [Multi-domain] Cd Length: 53 Bit Score: 45.32 E-value: 2.39e-06

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gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYVK 184
Cdd:cd11856     4 AIADYEAQGDDEISLQEGEVVEVLEKNDSgWWYVRKGDKEGWVPASYLE 52

Src homology 3 domain of APC-Stimulated guanine nucleotide Exchange Factor 2; ASEF2, also called Spermatogenesis-associated protein 13 (SPATA13), is a GEF that localizes with actin at the leading edge of cells and is important in cell migration and adhesion dynamics. GEFs activate small GTPases by exchanging bound GDP for free GTP. ASEF2 can activate both Rac 1 and Cdc42, but only Rac1 activation is necessary for increased cell migration and adhesion turnover. Together with APC (adenomatous polyposis coli) and Neurabin2, a scaffold protein that binds F-actin, it is involved in regulating HGF-induced cell migration. ASEF2 contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212907 Cd Length: 54 Bit Score: 45.44 E-value: 2.43e-06

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gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLE-QQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11974     3 AEALWDHVTMDDQELAFKAGDVIRVLEaSNKDWWWGRNEDREAWFPASFVRL 54

Src homology 3 domain of Proline-Serine-Threonine Phosphatase-Interacting Protein 1; PSTPIP1, also called CD2 Binding Protein 1 (CD2BP1), is mainly expressed in hematopoietic cells. It is a binding partner of the cell surface receptor CD2 and PTP-PEST, a tyrosine phosphatase which functions in cell motility and Rac1 regulation. It also plays a role in the activation of the Wiskott-Aldrich syndrome protein (WASP), which couples actin rearrangement and T cell activation. Mutations in the gene encoding PSTPIP1 cause the autoinflammatory disorder known as PAPA (pyogenic sterile arthritis, pyoderma gangrenosum, and acne) syndrome. PSTPIP1 contains an N-terminal F-BAR domain, PEST motifs, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212758 [Multi-domain] Cd Length: 53 Bit Score: 45.44 E-value: 2.54e-06

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gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11824     1 KYSVLYDYTAQEDDELSISKGDVVAVIEKGEDgWWTVERNGQKGLVPGTYLEK 53

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213017 [Multi-domain] Cd Length: 57 Bit Score: 45.57 E-value: 2.55e-06

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gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDD----PDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12141     4 AVYTFKARSPNELSVSANQRVRILEFSDltgnKEWWLAEANGQKGYVPSNYIR 56

N-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also have roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The N-terminal SH3 domain of the related protein GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212880 [Multi-domain] Cd Length: 52 Bit Score: 45.17 E-value: 2.71e-06

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gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11947     1 EARGKFDFTASGEDELSFKKGDVLKILSSDDIWFKAELNGEEGYVPKNFVDI 52

Src Homology 3 domain of SH3 domain-binding protein 4; SH3 domain-binding protein 4 (SH3BP4) is also called transferrin receptor trafficking protein (TTP). SH3BP4 is an endocytic accessory protein that interacts with endocytic proteins including clathrin and dynamin, and regulates the internalization of the transferrin receptor (TfR). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212691 Cd Length: 52 Bit Score: 45.40 E-value: 2.73e-06

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gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11757     1 EVVAIKDYCPTNFTTLKFSKGDHLYVLDTSGGEWWYAHNTTEMGYIPSSYVQ 52

Third Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212717 [Multi-domain] Cd Length: 55 Bit Score: 45.08 E-value: 2.88e-06

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gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGE--INGVTGLFPSNYVK 414
Cdd:cd11783     2 YVALYPYKPQKPDELELRKGEMYTVTEKCQDGWFKGTslRTGQSGVFPGNYVQ 54

Second Src homology 3 domain (or SH3B) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The second SH3 domain (or SH3B) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212923 [Multi-domain] Cd Length: 52 Bit Score: 45.03 E-value: 3.15e-06

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gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDpDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11990     4 ALCSWTAKKDNHLNFSKNDIITVLEQQE-NWWFGEVHGGRGWFPKSYVKL 52

Second Src homology 3 domain of Tyrosine kinase substrate with four SH3 domains; Tks4, also called SH3 and PX domain-containing protein 2B (SH3PXD2B) or HOFI, is a Src substrate and scaffolding protein that plays an important role in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. It is required in the formation of functional podosomes, EGF-induced membrane ruffling, and lamellipodia generation. It plays an important role in cellular attachment and cell spreading. Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. It contains an N-terminal Phox homology (PX) domain and four SH3 domains. This model characterizes the second SH3 domain of Tks4. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213009 [Multi-domain] Cd Length: 54 Bit Score: 45.02 E-value: 3.27e-06

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gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12076     4 TVIYPYTARDQDEINLEKGAVVEVIQKNLEGWWKIRYQGKEGWAPASYLK 53

Src Homology 3 domain of Class A and B Dedicator of Cytokinesis proteins; DOCK proteins are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. They are divided into four classes (A-D) based on sequence similarity and domain architecture: class A includes Dock1, 2 and 5; class B includes Dock3 and 4; class C includes Dock6, 7, and 8; and class D includes Dock9, 10 and 11. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. This subfamily includes only Class A and B DOCKs, which also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus. Class A/B DOCKs are mostly specific GEFs for Rac, except Dock4 which activates the Ras family GTPase Rap1, probably indirectly through interaction with Rap regulatory proteins. The SH3 domain of class A/B DOCKs have been shown to bind Elmo, a scaffold protein that promotes GEF activity of DOCKs by releasing DHR-2 autoinhibition by the intramolecular SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212805 [Multi-domain] Cd Length: 56 Bit Score: 44.88 E-value: 3.29e-06

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gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQENWWFGEV---HGGRGWFPKSYVKI 185
Cdd:cd11872     4 AIYNFQGDGEHQLSLQVGDTVQILEECEGWYRGFSlrnKSLKGIFPKSYVHI 55

Src Homology 3 domain of SH3 domain-containing protein 21 (SH3D21) and similar proteins; N-terminal SH3 domain of the uncharacterized protein SH3 domain-containing protein 21, and similar uncharacterized domains, it belongs to the CD2AP-like_3 subfamily of proteins. The CD2AP-like_3 subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213018 [Multi-domain] Cd Length: 55 Bit Score: 45.15 E-value: 3.34e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 221 LYPYSSVEPGDLTFTEGEEILVTQKDGE---WWTGSIGDRSGIFPSNYVKP 268
Cdd:cd12142     5 LFDYNPVAPDELALKKGDVIEVISKETEdegWWEGELNGRRGFFPDNFVMP 55

Src homology 3 domain of Hematopoietic lineage cell-specific protein 1; HS1, also called HCLS1 (hematopoietic cell-specific Lyn substrate 1), is a cortactin homolog expressed specifically in hematopoietic cells. It is an actin regulatory protein that binds the Arp2/3 complex and stabilizes branched actin filaments. It is required for cell spreading and signaling in lymphocytes. It regulates cytoskeletal remodeling that controls lymphocyte trafficking, and it also affects tissue invasion and infiltration of leukemic B cells. Like cortactin, HS1 contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region binds the Arp2/3 complex and F-actin, while the C-terminal region acts as an adaptor or scaffold that can connect varied proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213006 [Multi-domain] Cd Length: 55 Bit Score: 44.82 E-value: 3.46e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd12073     3 AVALYDYQGEGDDEISFDPQETITDIEMvDEGWWKGTCHGHRGLFPANYVEL 54

First Src homology 3 domain (or SH3A) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN2 is expected to bind many protein partners, similar to ITSN1 which has been shown to bind Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212921 [Multi-domain] Cd Length: 57 Bit Score: 44.86 E-value: 3.65e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD--DPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd11988     6 ALYPFEARNHDEMSFNAGDIIQVDEKTvgEPGWLYGSFQGNFGWFPCNYVE 56

Second Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212855 [Multi-domain] Cd Length: 58 Bit Score: 44.98 E-value: 3.66e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVT--GLFPSNYVKM 415
Cdd:cd11922     2 EAIAKFNFNGDTQVEMSFRKGERITLLRQVDENWYEGRIPGTSrqGIFPITYVDV 56

Src homology 3 domain of eumetazoan Actin-binding protein 1; Abp1, also called drebrin-like protein, is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a helical domain, and a C-terminal SH3 domain. Mammalian Abp1, unlike yeast Abp1, does not contain an acidic domain that interacts with the Arp2/3 complex. It regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. Abp1 deficiency causes abnormal organ structure and function of the spleen, heart, and lung of mice. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212893 [Multi-domain] Cd Length: 54 Bit Score: 44.70 E-value: 3.76e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGD-RSGIFPSNYVK 267
Cdd:cd11960     4 ALYDYQAADDTEISFDPGDIITdIEQIDEGWWRGTGPDgTYGLFPANYVE 53

Src Homology 3 domain of Membrane Protein, Palmitoylated 1 (or MAGUK p55 subfamily member 1)-like proteins; This subfamily includes MPP1, CASK (Calcium/calmodulin-dependent Serine protein Kinase), Caenorhabditis elegans lin-2, and similar proteins. MPP1 and CASK are scaffolding proteins from the MAGUK (membrane-associated guanylate kinase) protein family, which is characterized by the presence of a core of three domains: PDZ, SH3, and guanylate kinase (GuK). In addition, they also have the Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. CASK and lin-2 also contain an N-terminal calmodulin-dependent kinase (CaMK)-like domain and two L27 domains. MPP1 is ubiquitously-expressed and plays roles in regulating neutrophil polarity, cell shape, hair cell development, and neural development and patterning of the retina. CASK is highly expressed in the mammalian nervous system and plays roles in synaptic protein targeting, neural development, and gene expression regulation. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212968 Cd Length: 62 Bit Score: 45.12 E-value: 3.97e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 364 VIAMYDYAANNED-------ELSFSKGQLINVMNKDDPDWWQ----GEINGVTGLFPS 410
Cdd:cd12035     2 VRAQFDYDPSKDDlipcqqaGIAFKTGDILQIISKDDHNWWQarkpGASKEPAGLIPS 59

C-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also has roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRAP2 binds to different motifs found in substrate peptides including the typical PxxP motif in hematopoietic progenitor kinase 1 (HPK1), the RxxK motif in SLP-76 and HPK1, and the RxxxxK motif in phosphatase-like protein HD-PTP. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212883 [Multi-domain] Cd Length: 53 Bit Score: 44.82 E-value: 4.06e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11950     2 VRALYDFEALEDDELGFNSGDVIEVLDSSNpSWWKGRLHGKLGLFPANYVA 52

Src homology 3 domain of High osmolarity signaling protein Sho1p; Sho1p (or Sho1), also called SSU81 (Suppressor of SUA8-1 mutation), is a yeast membrane protein that regulates adaptation to high salt conditions by activating the HOG (high-osmolarity glycerol) pathway. High salt concentrations lead to the localization to the membrane of the MAPKK Pbs2, which is then activated by the MAPKK Ste11 and in turn, activates the MAPK Hog1. Pbs2 is localized to the membrane though the interaction of its PxxP motif with the SH3 domain of Sho1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212789 [Multi-domain] Cd Length: 55 Bit Score: 44.72 E-value: 4.07e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPY--SSVEPGDLTFTEGEEILVTQKDGEWWTGSIGD-RSGIFPSNYV 266
Cdd:cd11855     4 ALYPYdaSPDDPNELSFEKGEILEVSDTSGKWWQARKSNgETGICPSNYL 53

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member 4; CASS4, also called HEPL (HEF1-EFS-p130Cas-like), localizes to focal adhesions and plays a role in regulating FAK activity, focal adhesion integrity, and cell spreading. It is most abundant in blood cells and lung tissue, and is also found in high levels in leukemia and ovarian cell lines. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212933 Cd Length: 57 Bit Score: 44.87 E-value: 4.09e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPD---WWQGEINGVTGLFPSN 411
Cdd:cd12000     5 ALYDNKADCSDELAFRRGDILTVLEQNVPGsegWWKCLLHGRQGLAPAN 53

First Src Homology 3 domain (SH3A) of CD2-associated protein and similar proteins; This subfamily is composed of the first SH3 domain (SH3A) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3A of both proteins bind to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic domain of the cell adhesion protein CD2. CIN85 SH3A binds to internal proline-rich motifs within the proline-rich region; this intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. CIN85 SH3A has also been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212806 [Multi-domain] Cd Length: 53 Bit Score: 44.56 E-value: 4.61e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1370477838 141 WTAKKDNHLNFSKHDIIT-VLEQQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11873     8 YDAEEPDELTLKVGDIITnVKKMEEGWWEGTLNGKRGMFPDNFVKV 53

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase 2; GRAF2, also called Rho GTPase activating protein 10 (ARHGAP10) or PS-GAP, is a GAP with activity towards Cdc42 and RhoA. It regulates caspase-activated p21-activated protein kinase-2 (PAK-2p34). GRAF2 interacts with PAK-2p34, leading to its stabilization and decrease of cell death. It is highly expressed in skeletal muscle, and is involved in alpha-catenin recruitment at cell-cell junctions. GRAF2 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. The SH3 domain of GRAF binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212998 [Multi-domain] Cd Length: 54 Bit Score: 44.59 E-value: 4.63e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 366 AMYDYAANNEDELSFSKGQLI-NVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd12065     4 AVYPCEAEHSSELSFEVGAIFeDVTLSREPGWLEGTLNGKRGLIPENYVEI 54

Src homology 3 domain of the CAS (Crk-Associated Substrate) scaffolding protein family member, Breast Cancer Anti-estrogen Resistance 1; BCAR1, also called p130cas or CASS1, is the founding member of the CAS family of scaffolding proteins and was originally identified through its ability to associate with Crk. The name BCAR1 was designated because the human gene was identified in a screen for genes that promote resistance to tamoxifen. It is widely expressed and its deletion is lethal in mice. It plays a role in regulating cell motility, survival, proliferation, transformation, cancer progression, and bacterial pathogenesis. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212934 Cd Length: 68 Bit Score: 45.03 E-value: 4.67e-06

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 132 NLKAQALCSWTAKKDNHLNFSKHDIITVLEQQ----ENWWFGEVHGGRGWFPKSYVKIIPG 188
Cdd:cd12001     2 NVLAKALYDNVAESPDELSFRKGDIMTVLERDtqglDGWWLCSLHGRQGIVPGNRLKILVG 62

Src homology 3 domain of Type I fungal Myosins; Type I myosins (myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Saccharomyces cerevisiae has two myosins-I, Myo3 and Myo5, which are involved in endocytosis and the polarization of the actin cytoskeleton. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212792 [Multi-domain] Cd Length: 55 Bit Score: 44.68 E-value: 4.69e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVT--GLFPSNYVK 414
Cdd:cd11858     4 ALYDFAGSVANELSLKKDDIVYIVQKEDNGWWLAKKLDESkeGWVPAAYLE 54

Src Homology 3 domain of Brain-specific Angiogenesis Inhibitor 1-Associated Protein 2-Like 2; BAIAP2L2 co-localizes with clathrin plaques but its function has not been determined. It contains an N-terminal IMD or Inverse-Bin/Amphiphysin/Rvs (I-BAR) domain, an SH3 domain, and a WASP homology 2 (WH2) actin-binding motif at the C-terminus. The related proteins, BAIAP2L1 and IRSp53, function as regulators of membrane dynamics and the actin cytoskeleton. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212847 [Multi-domain] Cd Length: 59 Bit Score: 44.81 E-value: 4.82e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 136 QALCSWTAKKdNH--LNFSKHDIITVL--EQQENWWFGEVHGG--RGWFPKSYVK 184
Cdd:cd11914     4 RAIVSHPAGS-NPtlLRFNRGDIITVLvpEARNGWLYGKLEGSsrQGWFPEAYVK 57

C2 domain second repeat in Munc13 (mammalian uncoordinated)-like proteins; C2-like domains are thought to be involved in phospholipid binding in a Ca2+ independent manner in both Unc13 and Munc13. Caenorabditis elegans Unc13 has a central domain with sequence similarity to PKC, which includes C1 and C2-related domains. Unc13 binds phorbol esters and DAG with high affinity in a phospholipid manner. Mutations in Unc13 results in abnormal neuronal connections and impairment in cholinergic neurotransmission in the nematode. Munc13 is the mammalian homolog which are expressed in the brain. There are 3 isoforms (Munc13-1, -2, -3) and are thought to play a role in neurotransmitter release and are hypothesized to be high-affinity receptors for phorbol esters. Unc13 and Munc13 contain both C1 and C2 domains. There are two C2 related domains present, one central and one at the carboxyl end. Munc13-1 contains a third C2-like domain. Munc13 interacts with syntaxin, synaptobrevin, and synaptotagmin suggesting a role for these as scaffolding proteins. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the third C2 repeat, C2C, and has a type-II topology.

Pssm-ID: 175976 [Multi-domain] Cd Length: 133 Bit Score: 46.85 E-value: 4.96e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 790 YQARSQKtsgigrLMVHVIEATELKACKPNGKSNPYCEISM-------GSQSYTTRTIQDTLNPKWNFNCQFFIKD---- 858
Cdd:cd04009    11 YRASEQS------LRVEILNARNLLPLDSNGSSDPFVKVELlprhlfpDVPTPKTQVKKKTLFPLFDESFEFNVPPeqcs 84

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 859 LYQDVLCLTLFDRDQFSPDDFLGRT-----EIPVAKIRTEQESKGPMT 901
Cdd:cd04009    85 VEGALLLFTVKDYDLLGSNDFEGEAflplnDIPGVEDTSSAQGFGPLP 132

Src Homology 3 domain of TXK, also called Resting lymphocyte kinase (Rlk); TXK is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal cysteine-rich region. Rlk is expressed in T-cells and mast cell lines, and is a key component of T-cell receptor (TCR) signaling. It is important in TCR-stimulated proliferation, IL-2 production and phospholipase C-gamma1 activation. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212840 [Multi-domain] Cd Length: 55 Bit Score: 44.56 E-value: 5.05e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEIN-GVTGLFPSNYV 413
Cdd:cd11907     2 QVKALYDFLPREPSNLALKRAEEYLILEQYDPHWWKARDRyGNEGLIPSNYV 53

Second Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212834 [Multi-domain] Cd Length: 55 Bit Score: 44.64 E-value: 5.06e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHV 344
Cdd:cd11901     4 AYVKFNYTAEREDELSLVKGTKVIVMEKCSDGWWRGSYNGQ-----VGWFPSNYV 53

Second Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the second SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212716 [Multi-domain] Cd Length: 53 Bit Score: 44.26 E-value: 5.14e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11782     1 EARAKYNFNADTGVELSFRKGDVITLTRRvDENWYEGRIGGRQGIFPVSYVQV 53

Src Homology 3 (SH3) domain of Apoptosis Stimulating of p53 protein 2; ASPP2 is the full length form of the previously-identified tumor supressor, p53-binding protein 2 (p53BP2). ASPP2 activates the apoptotic function of the p53 family of tumor suppressors (p53, p63, and p73). It plays a central role in regulating apoptosis and cell growth; ASPP2-deficient mice show postnatal death. Downregulated expression of ASPP2 is frequently found in breast tumors, lung cancer, and diffuse large B-cell lymphoma where it is correlated with a poor clinical outcome. ASPP2 contains a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain at its C-terminal half. The SH3 domain and the ANK repeats of ASPP2 contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212886 [Multi-domain] Cd Length: 57 Bit Score: 44.56 E-value: 5.59e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPD---WWQGEINGVTGLFPSN 411
Cdd:cd11953     3 VYALWDYEGESDDELSFKEGDCMTILRREDEDeteWWWARLNDKEGYVPRN 53

Second Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212856 [Multi-domain] Cd Length: 57 Bit Score: 44.52 E-value: 5.78e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVT--GLFPSNYVKM 415
Cdd:cd11923     2 EAVAKYNFNADTNVELSLRKGDRVVLLKQVDQNWYEGKIPGTNrqGIFPVSYVEV 56

First Src homology 3 domain (or SH3A) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212770 [Multi-domain] Cd Length: 55 Bit Score: 44.27 E-value: 5.81e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKD-GE--WWTGSIGDRSGIFPSNYV 266
Cdd:cd11836     2 YRALYAFEARNPDEISFQPGDIIQVDESQvAEpgWLAGELKGKTGWFPANYV 53

First Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the first SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212715 [Multi-domain] Cd Length: 53 Bit Score: 44.25 E-value: 5.99e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11781     3 RALYPFKAQSAKELSLKKGDIIYIRRQiDKNWYEGEHNGRVGIFPASYVEI 53

C2 domain second repeat in Munc13 (mammalian uncoordinated) proteins; C2-like domains are thought to be involved in phospholipid binding in a Ca2+ independent manner in both Unc13 and Munc13. Caenorabditis elegans Unc13 has a central domain with sequence similarity to PKC, which includes C1 and C2-related domains. Unc13 binds phorbol esters and DAG with high affinity in a phospholipid manner. Mutations in Unc13 results in abnormal neuronal connections and impairment in cholinergic neurotransmission in the nematode. Munc13 is the mammalian homolog which are expressed in the brain. There are 3 isoforms (Munc13-1, -2, -3) and are thought to play a role in neurotransmitter release and are hypothesized to be high-affinity receptors for phorbol esters. Unc13 and Munc13 contain both C1 and C2 domains. There are two C2 related domains present, one central and one at the carboxyl end. Munc13-1 contains a third C2-like domain. Munc13 interacts with syntaxin, synaptobrevin, and synaptotagmin suggesting a role for these as scaffolding proteins. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

Pssm-ID: 175993 [Multi-domain] Cd Length: 127 Bit Score: 46.41 E-value: 6.20e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 802 RLMVHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDlYQDVLCLTLFDRD--------- 872
Cdd:cd04027     2 KISITVVCAQGLIAKDKTGTSDPYVTVQVGKTKKRTKTIPQNLNPVWNEKFHFECHN-SSDRIKVRVWDEDddiksrlkq 80

                          90       100
                  ....*....|....*....|....*
gi 1370477838 873 QFS--PDDFLGRTEIPVAKIRTEQE 895
Cdd:cd04027    81 KFTreSDDFLGQTIIEVRTLSGEMD 105

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 2; SKAP2, also called SKAP55-Related (SKAP55R) or SKAP55 homolog (SKAP-HOM or SKAP55-HOM), is an immune cell-specific adaptor protein that plays an important role in adhesion and migration of B-cells and macrophages. Binding partners include ADAP (adhesion and degranulation-promoting adaptor protein), YopH, SHPS1, and HPK1. SKAP2 has also been identified as a substrate for lymphoid-specific tyrosine phosphatase (Lyp), which has been implicated in a wide variety of autoimmune diseases. It contains a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. Like SKAP1, SKAP2 is expected to bind primarily to a proline-rich region of ADAP through its SH3 domain; its degradation may be regulated by ADAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212978 Cd Length: 53 Bit Score: 44.12 E-value: 6.30e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 367 MYDYAANNEDELSFSKGQLINVMNK--DDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd12045     5 LWDCTGDQPDELSFKRGDTIYILSKeyNRFGWWVGEMKGTIGLVPKAYI 53

Src homology 3 domain of Cortactin and related proteins; This subfamily includes cortactin, Abp1 (actin-binding protein 1), hematopoietic lineage cell-specific protein 1 (HS1), and similar proteins. These proteins are involved in regulating actin dynamics through direct or indirect interaction with the Arp2/3 complex, which is required to initiate actin polymerization. They all contain at least one C-terminal SH3 domain. Cortactin and HS1 bind Arp2/3 and actin through an N-terminal region that contains an acidic domain and several copies of a repeat domain found in cortactin and HS1. Abp1 binds actin via an N-terminal actin-depolymerizing factor (ADF) homology domain. Yeast Abp1 binds Arp2/3 directly through two acidic domains. Mammalian Abp1 does not directly interact with Arp2/3; instead, it regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. The C-terminal region of these proteins acts as an adaptor or scaffold that can connect membrane trafficking and signaling proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212753 [Multi-domain] Cd Length: 54 Bit Score: 44.23 E-value: 6.32e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGElqarGKKRQKGWFPASHVKL 346
Cdd:cd11819     8 YQAAEDNEISFVEGDIITQIEQIDEGWWLGV----NAKGQKGLFPANYVEL 54

C2 domain of Perforin; Perforin contains a single copy of a C2 domain in its C-terminus and plays a role in lymphocyte-mediated cytotoxicity. Mutations in perforin leads to familial hemophagocytic lymphohistiocytosis type 2. The function of perforin is calcium dependent and the C2 domain is thought to confer this binding to target cell membranes. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 175998 [Multi-domain] Cd Length: 127 Bit Score: 46.49 E-value: 6.52e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 799 GIGRLMVHVIEATELkackpNG----KSNPYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQ-DVLCLTLFDRDQ 873
Cdd:cd04032    26 GLATLTVTVLRATGL-----WGdyftSTDGYVKVFFGGQEKRTEVIWNNNNPRWNATFDFGSVELSPgGKLRFEVWDRDN 100

                          90
                  ....*....|....
gi 1370477838 874 FSPDDFLGRTEIPV 887
Cdd:cd04032   101 GWDDDLLGTCSVVP 114

First Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212853 [Multi-domain] Cd Length: 55 Bit Score: 44.23 E-value: 7.40e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 133 LKAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11920     1 LPARAVYDFKAQTSKELSFKKGDTVYILRKiDQNWYEGEHHGRVGIFPISYVE 53

Second Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212749 [Multi-domain] Cd Length: 52 Bit Score: 44.09 E-value: 7.70e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11815     3 VVLHDFPAEHSDDLSLNSGEIVYLLEKiDTEWYRGKCKNTTGIFPANHVK 52

Src Homology 3 domain of Tec (Tyrosine kinase expressed in hepatocellular carcinoma); Tec is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation, and the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. It is more widely-expressed than other Tec subfamily kinases. Tec is found in endothelial cells, both B- and T-cells, and a variety of myeloid cells including mast cells, erythroid cells, platelets, macrophages and neutrophils. Tec is a key component of T-cell receptor (TCR) signaling, and is important in TCR-stimulated proliferation, IL-2 production and phospholipase C-gamma1 activation. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212838 [Multi-domain] Cd Length: 56 Bit Score: 44.03 E-value: 7.73e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQG-EINGVTGLFPSNYV 413
Cdd:cd11905     3 VVAMYDFQPTEPHDLRLETGEEYVILEKNDVHWWKArDKYGKEGYIPSNYV 53

N-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The N-terminal SH3 domain of the related protein GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212881 [Multi-domain] Cd Length: 54 Bit Score: 44.04 E-value: 8.10e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVL--EQQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11948     1 EAVALYSFQATESDELPFQKGDILKILnmEDDQNWYKAELQGREGYIPKNYIKV 54

Src homology 3 domain of the Rho guanine nucleotide exchange factor ARHGEF9; ARHGEF9, also called PEM2 or collybistin, selectively activates Cdc42 by exchanging bound GDP for free GTP. It is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. Mutations in the ARHGEF9 gene cause X-linked mental retardation with associated features like seizures, hyper-anxiety, aggressive behavior, and sensory hyperarousal. ARHGEF9 contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212908 Cd Length: 62 Bit Score: 44.32 E-value: 8.27e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11975     9 AVWDHVTMANRELAFKAGDVIKVLDASNKDWWWGQIDDEEGWFPASFVRL 58

Src Homology 3 domain of Membrane Protein, Palmitoylated 5 (or MAGUK p55 subfamily member 5); MPP5, also called PALS1 (Protein associated with Lin7) or Nagie oko protein in zebrafish or Stardust in Drosophila, is a scaffolding protein which associates with Crumbs homolog 1 (CRB1), CRB2, or CRB3 through its PDZ domain and with PALS1-associated tight junction protein (PATJ) or multi-PDZ domain protein 1 (MUPP1) through its L27 domain. The resulting tri-protein complexes are core proteins of the Crumb complex, which localizes at tight junctions or subapical regions, and is involved in the maintenance of apical-basal polarity in epithelial cells and the morphogenesis and function of photoreceptor cells. MPP5 is critical for the proper stratification of the retina and is also expressed in T lymphocytes where it is important for TCR-mediated activation of NFkB. Drosophila Stardust exists in several isoforms, some of which show opposing functions in photoreceptor cells, which suggests that the relative ratio of different Crumbs complexes regulates photoreceptor homeostasis. MPP5 contains two L27 domains followed by the core of three domains characteristic of MAGUK (membrane-associated guanylate kinase) proteins: PDZ, SH3, and guanylate kinase (GuK). In addition, it also contains the Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212969 Cd Length: 63 Bit Score: 43.94 E-value: 8.53e-06

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 364 VIAMYDYaaNNEDE---------LSFSKGQLINVMNKDDPDWWQGEING------VTGLFPS 410
Cdd:cd12036     2 VRAHFDY--DPEDDpyipcrelgLSFQKGDILHVISQEDPNWWQAYREGeednqsLAGLIPS 61

Src Homology 3 domain of Tec (Tyrosine kinase expressed in hepatocellular carcinoma); Tec is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation, and the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. It is more widely-expressed than other Tec subfamily kinases. Tec is found in endothelial cells, both B- and T-cells, and a variety of myeloid cells including mast cells, erythroid cells, platelets, macrophages and neutrophils. Tec is a key component of T-cell receptor (TCR) signaling, and is important in TCR-stimulated proliferation, IL-2 production and phospholipase C-gamma1 activation. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212838 [Multi-domain] Cd Length: 56 Bit Score: 44.03 E-value: 8.53e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 216 EEYIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSigDR---SGIFPSNYVKPK 269
Cdd:cd11905     1 EIVVAMYDFQPTEPHDLRLETGEEYVILEKnDVHWWKAR--DKygkEGYIPSNYVTGK 56

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 1; ASAP1 is also called DDEF1 (Development and Differentiation Enhancing Factor 1), AMAP1, centaurin beta-4, or PAG2. an Arf GTPase activating protein (GAP) with activity towards Arf1 and Arf5 but not Arf6. However, it has been shown to bind GTP-Arf6 stably without GAP activity. It has been implicated in cell growth, migration, and survival, as well as in tumor invasion and malignancy. It binds paxillin and cortactin, two components of invadopodia which are essential for tumor invasiveness. It also binds focal adhesion kinase (FAK) and the SH2/SH3 adaptor CrkL. ASAP1 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212898 [Multi-domain] Cd Length: 57 Bit Score: 43.84 E-value: 8.61e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1370477838 231 DLTFTEGEEILVT-QKDGEWWTGSIG---DRSGIFPSNYV 266
Cdd:cd11965    15 ELTFVEGEVIIVTgEEDQEWWIGHIEgqpERKGVFPVSFV 54

Third N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP binds the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212730 Cd Length: 51 Bit Score: 43.88 E-value: 8.78e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQENWWF-GEVHGGRGWFPKSYV 183
Cdd:cd11796     1 QARVLQDLSAQLDEELDLREGDVVTITGILDKGWFrGELNGRRGIFPEGFV 51

C2 domain first repeat in Copine; There are 2 copies of the C2 domain present in copine, a protein involved in membrane trafficking, protein-protein interactions, and perhaps even cell division and growth. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 176013 [Multi-domain] Cd Length: 120 Bit Score: 45.64 E-value: 8.96e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 821 KSNPYCEISM---GSQSYT----TRTIQDTLNPkwNFNCQFFIKDLYQDV--LCLTLFDRDQFSPD----DFLGRTEIPV 887
Cdd:cd04048    20 KSDPFVVVYVktgGSGQWVeigrTEVIKNNLNP--DFVTTFTVDYYFEEVqkLRFEVYDVDSKSKDlsdhDFLGEAECTL 97

                          90
                  ....*....|....
gi 1370477838 888 AKIRTEQESKGPMT 901
Cdd:cd04048    98 GEIVSSPGQKLTLP 111

Src Homology 3 domain of Myosin XV; This subfamily is composed of proteins with similarity to Myosin XVa. Myosin XVa is an unconventional myosin that is critical for the normal growth of mechanosensory stereocilia of inner ear hair cells. Mutations in the myosin XVa gene are associated with nonsyndromic hearing loss. Myosin XVa contains a unique N-terminal extension followed by a motor domain, light chain-binding IQ motifs, and a tail consisting of a pair of MyTH4-FERM tandems separated by a SH3 domain, and a PDZ domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212817 [Multi-domain] Cd Length: 56 Bit Score: 43.85 E-value: 9.03e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGE----WWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11884     3 VAVRAYITRDQTLLSFHKGDVIKLLPKEGPldpgWLFGTLDGRSGAFPKEYVQP 56

Src Homology 3 domain of Abelson helper integration site-1 (AHI-1); AHI-1, also called Jouberin, is expressed in high levels in the brain, gonad tissues, and skeletal muscle. It is an adaptor protein that interacts with the small GTPase Rab8a and regulates it distribution and function, affecting cilium formation and vesicle transport. Mutations in the AHI-1 gene can cause Joubert syndrome, a disorder characterized by brainstem malformations, cerebellar aplasia/hypoplasia, and retinal dystrophy. AHI-1 variation is also associated with susceptibility to schizophrenia and type 2 diabetes mellitus progression. AHI-1 contains WD40 and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212746 [Multi-domain] Cd Length: 52 Bit Score: 43.65 E-value: 9.18e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELqARGkkrQKGWFPASHV 344
Cdd:cd11812     8 YTANRSDELTIHRGDIIRVLYKDNDNWWFGSL-VNG---QQGYFPANYV 52

C2 domain second repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); plant subset; MCTPs are involved in Ca2+ signaling at the membrane. Plant-MCTPs are composed of a variable N-terminal sequence, four C2 domains, two transmembrane regions (TMRs), and a short C-terminal sequence. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

Pssm-ID: 176024 [Multi-domain] Cd Length: 121 Bit Score: 45.77 E-value: 9.50e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 802 RLMVHVIEATELkackPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWNfncQFFI--KDLYQ-DVLCLTLFDRDqFSPDD 878
Cdd:cd08378     1 YLYVRVVKARGL----PANSNDPVVEVKLGNYKGSTKAIERTSNPEWN---QVFAfsKDRLQgSTLEVSVWDKD-KAKDD 72

                          90
                  ....*....|....
gi 1370477838 879 FLGRTEIPVAKIRT 892
Cdd:cd08378    73 FLGGVCFDLSEVPT 86

Src homology 3 domain of Lck Protein Tyrosine Kinase; Lck is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Lck is expressed in T-cells and natural killer cells. It plays a critical role in T-cell maturation, activation, and T-cell receptor (TCR) signaling. Lck phosphorylates ITAM (immunoreceptor tyr activation motif) sequences on several subunits of TCRs, leading to the activation of different second messenger cascades. Phosphorylated ITAMs serve as binding sites for other signaling factor such as Syk and ZAP-70, leading to their activation and propagation of downstream events. In addition, Lck regulates drug-induced apoptosis by interfering with the mitochondrial death pathway. The apototic role of Lck is independent of its primary function in T-cell signaling. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212938 [Multi-domain] Cd Length: 54 Bit Score: 43.66 E-value: 9.71e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKdDPDWWQGE--INGVTGLFPSNYVKM 415
Cdd:cd12005     1 LVVALYSYEPSHDGDLGFEKGEKLRILEQ-SGEWWKAQslTTGQEGFIPFNFVAK 54

C-terminal (or second) Src homology 3 domain of VAV proteins; VAV proteins function both as cytoplasmic guanine nucleotide exchange factors (GEFs) for Rho GTPases and scaffold proteins and they play important roles in cell signaling by coupling cell surface receptors to various effector functions. They play key roles in processes that require cytoskeletal reorganization including immune synapse formation, phagocytosis, cell spreading, and platelet aggregation, among others. Vertebrates have three VAV proteins (VAV1, VAV2, and VAV3). VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212764 [Multi-domain] Cd Length: 54 Bit Score: 43.77 E-value: 9.80e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQ--QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11830     2 AKARYDFCARDMRELSLKEGDVVKIYNKkgQQGWWRGEINGRIGWFPSTYVE 53

First Src Homology 3 domain of Nck adaptor proteins; Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The first SH3 domain of Nck proteins preferentially binds the PxxDY sequence, which is present in the CD3e cytoplasmic tail. This binding inhibits phosphorylation by Src kinases, resulting in the downregulation of TCR surface expression. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212699 [Multi-domain] Cd Length: 51 Bit Score: 43.56 E-value: 9.93e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNkDDPDWWQGE-INGVTGLFPSNYV 413
Cdd:cd11765     2 VVAKYDYTAQGDQELSIKKNEKLTLLD-DSKHWWKVQnSSNQTGYVPSNYV 51

Src homology 3 domain of APC-Stimulated guanine nucleotide Exchange Factor; ASEF, also called ARHGEF4, exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli). GEFs activate small GTPases by exchanging bound GDP for free GTP. ASEF can activate Rac1 or Cdc42. Truncated ASEF, which is found in colorectal cancers, is constitutively active and has been shown to promote angiogenesis and cancer cell migration. ASEF contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212906 [Multi-domain] Cd Length: 73 Bit Score: 44.24 E-value: 1.00e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11973    22 ALWDHVTMDDQELGFKAGDVIEVMDATNKEWWWGRVLDSEGWFPASFVRL 71

Third Src Homology 3 domain (SH3C) of CD2-associated protein and similar proteins; This subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212808 [Multi-domain] Cd Length: 55 Bit Score: 43.49 E-value: 1.03e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLE---QQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11875     1 KARVLFDYEAENEDELTLREGDIVTILSkdcEDKGWWKGELNGKRGVFPDNFVEP 55

Src Homology 3 domain of TXK, also called Resting lymphocyte kinase (Rlk); TXK is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal cysteine-rich region. Rlk is expressed in T-cells and mast cell lines, and is a key component of T-cell receptor (TCR) signaling. It is important in TCR-stimulated proliferation, IL-2 production and phospholipase C-gamma1 activation. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212840 [Multi-domain] Cd Length: 55 Bit Score: 43.79 E-value: 1.03e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSigDR---SGIFPSNYV 266
Cdd:cd11907     4 KALYDFLPREPSNLALKRAEEYLILEQyDPHWWKAR--DRygnEGLIPSNYV 53

Src Homology 3 domain of Insulin Receptor tyrosine kinase Substrate p53, Brain-specific Angiogenesis Inhibitor 1-Associated Protein 2 (BAIAP2)-Like proteins, and similar proteins; Proteins in this family include IRSp53, BAIAP2L1, BAIAP2L2, and similar proteins. They all contain an Inverse-Bin/Amphiphysin/Rvs (I-BAR) or IMD domain in addition to the SH3 domain. IRSp53, also known as BAIAP2, is a scaffolding protein that takes part in many signaling pathways including Cdc42-induced filopodia formation, Rac-mediated lamellipodia extension, and spine morphogenesis. IRSp53 exists as multiple splicing variants that differ mainly at the C-termini. BAIAP2L1, also called IRTKS (Insulin Receptor Tyrosine Kinase Substrate), serves as a substrate for the insulin receptor and binds the small GTPase Rac. It plays a role in regulating the actin cytoskeleton and colocalizes with F-actin, cortactin, VASP, and vinculin. IRSp53 and IRTKS also mediate the recruitment of effector proteins Tir and EspFu, which regulate host cell actin reorganization, to bacterial attachment sites. BAIAP2L2 co-localizes with clathrin plaques but its function has not been determined. The SH3 domains of IRSp53 and IRTKS have been shown to bind the proline-rich C-terminus of EspFu. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212713 [Multi-domain] Cd Length: 57 Bit Score: 43.85 E-value: 1.04e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 295 AYVASGSEQLSLAPGQLI-LILKKNTSGWWQGELQargKKRQKGWFPASHVK 345
Cdd:cd11779     8 PHAAGGETQLSFEEGDVItLLGPEPRDGWHYGENE---RSGRRGWFPIAYTE 56

Src Homology 3 domain of Sorting Nexin 9 and similar proteins; Sorting nexins (SNXs) are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. This subfamily consists of SH3 domain containing SNXs including SNX9, SNX18, SNX33, and similar proteins. SNX9 is localized to plasma membrane endocytic sites and acts primarily in clathrin-mediated endocytosis, while SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212697 [Multi-domain] Cd Length: 55 Bit Score: 43.47 E-value: 1.08e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQ--ENWWFGE-VHGGRGWFPKSYVKI 185
Cdd:cd11763     1 KVRALYDFDSQPSGELSLRAGEVLTITRQDvgDGWLEGRnSRGEVGLFPSSYVEI 55

Src homology 3 domain of APC-Stimulated guanine nucleotide Exchange Factor; ASEF, also called ARHGEF4, exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli). GEFs activate small GTPases by exchanging bound GDP for free GTP. ASEF can activate Rac1 or Cdc42. Truncated ASEF, which is found in colorectal cancers, is constitutively active and has been shown to promote angiogenesis and cancer cell migration. ASEF contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212906 [Multi-domain] Cd Length: 73 Bit Score: 44.24 E-value: 1.09e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLE-QQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11973    20 AEALWDHVTMDDQELGFKAGDVIEVMDaTNKEWWWGRVLDSEGWFPASFVRL 71

Src Homology 3 domain of Pak Interactive eXchange factors; PIX proteins are Rho guanine nucleotide exchange factors (GEFs), which activate small GTPases by exchanging bound GDP for free GTP. They act as GEFs for both Cdc42 and Rac 1, and have been implicated in cell motility, adhesion, neurite outgrowth, and cell polarity. Vertebrates contain two proteins from the PIX subfamily, alpha-PIX and beta-PIX. Alpha-PIX, also called ARHGEF6, is localized in dendritic spines where it regulates spine morphogenesis. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. Beta-PIX play roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212810 [Multi-domain] Cd Length: 53 Bit Score: 43.46 E-value: 1.13e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 289 IAQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHVKL 346
Cdd:cd11877     1 LVRAKFNFEGTNEDELSFDKGDIITVTQVVEGGWWEGTLNGK-----TGWFPSNYVKE 53

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. Also included in this subfamily is the second C-terminal SH3 domain of Rho guanine nucleotide exchange factor 37 (ARHGEF37), whose function is still unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212734 [Multi-domain] Cd Length: 57 Bit Score: 43.51 E-value: 1.14e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK-----DGEWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11800     2 YYALYTFEARSPGELSVTEGQVVTVLEKhdlkgNPEWWLVEDRGKQGYVPSNYLAK 57

C-terminal (or second) Src homology 3 domain of VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and it plays an important role in the development and activation of B and T cells. It is activated by tyrosine phosphorylation to function as a guanine nucleotide exchange factor (GEF) for Rho GTPases following cell surface receptor activation, triggering various effects such as cytoskeletal reorganization, transcription regulation, cell cycle progression, and calcium mobilization. It also serves as a scaffold protein and has been shown to interact with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76, and Syk, among others. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The C-terminal SH3 domain of Vav1 interacts with a wide variety of proteins including cytoskeletal regulators (zyxin), RNA-binding proteins (Sam68), transcriptional regulators, viral proteins, and dynamin 2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212909 [Multi-domain] Cd Length: 54 Bit Score: 43.39 E-value: 1.20e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILIL-KKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:cd11976     8 FCARDRSELSLKEGDIIKILnKKGQQGWWRGEIYGR-----VGWFPANYVE 53

Pleckstrin homology (PH) domain; PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

Pssm-ID: 275388 [Multi-domain] Cd Length: 92 Bit Score: 44.46 E-value: 1.22e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 669 HSGKLYKT-----KSNKELHGFLFNDFLLltymvkqfavssgseklFSSKSNAQFKMYKTPIFLNEVLVKLPTDPSSDEP 743
Cdd:cd00821     1 KEGYLLKRgggglKSWKKRWFVLFEGVLL-----------------YYKSKKDSSYKPKGSIPLSGILEVEEVSPKERPH 63

                          90       100
                  ....*....|....*....|....*....
gi 1370477838 744 VFHISH-IDRVYTLRTDNINERTAWVQKI 771
Cdd:cd00821    64 CFELVTpDGRTYYLQADSEEERQEWLKAL 92

Src homology 3 domain of Proline-Serine-Threonine Phosphatase-Interacting Protein 1; PSTPIP1, also called CD2 Binding Protein 1 (CD2BP1), is mainly expressed in hematopoietic cells. It is a binding partner of the cell surface receptor CD2 and PTP-PEST, a tyrosine phosphatase which functions in cell motility and Rac1 regulation. It also plays a role in the activation of the Wiskott-Aldrich syndrome protein (WASP), which couples actin rearrangement and T cell activation. Mutations in the gene encoding PSTPIP1 cause the autoinflammatory disorder known as PAPA (pyogenic sterile arthritis, pyoderma gangrenosum, and acne) syndrome. PSTPIP1 contains an N-terminal F-BAR domain, PEST motifs, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212758 [Multi-domain] Cd Length: 53 Bit Score: 43.52 E-value: 1.24e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDRSGIFPSNYVK 267
Cdd:cd11824     1 KYSVLYDYTAQEDDELSISKGDVVAVIEKGEDgWWTVERNGQKGLVPGTYLE 52

Src Homology 3 domain of Membrane Protein, Palmitoylated 6 (or MAGUK p55 subfamily member 6); MPP6, also called Veli-associated MAGUK 1 (VAM-1) or PALS2, is a scaffolding protein that binds to Veli-1, a homolog of Caenorhabditis Lin-7. It is one of seven vertebrate homologs of the Drosophila Stardust protein, which is required in establishing cell polarity, and it contains two L27 domains followed by the core of three domains characteristic of MAGUK (membrane-associated guanylate kinase) proteins: PDZ, SH3, and guanylate kinase (GuK). In addition, it also contains the Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212971 Cd Length: 61 Bit Score: 43.51 E-value: 1.28e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1370477838 375 EDELSFSKGQLINVMNKDDPDWWQG---EINGVTGLFPSNYV 413
Cdd:cd12038    20 EAGLKFSKGEILQIVNREDPNWWQAshvKEGGSAGLIPSQFL 61

Fourth Src homology 3 domain (or SH3D) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212773 [Multi-domain] Cd Length: 58 Bit Score: 43.48 E-value: 1.30e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 223 PYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDR-----SGIFPSNYVK 267
Cdd:cd11839     7 PFTATAENQLSLAVGQLVLVRKKSPSgWWEGELQARgkkrqIGWFPANYVK 57

Src homology 3 domain of Src Protein Tyrosine Kinase; Src (or c-Src) is a cytoplasmic (or non-receptor) PTK and is the vertebrate homolog of the oncogenic protein (v-Src) from Rous sarcoma virus. Together with other Src subfamily proteins, it is involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. Src also play a role in regulating cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Elevated levels of Src kinase activity have been reported in a variety of human cancers. Several inhibitors of Src have been developed as anti-cancer drugs. Src is also implicated in acute inflammatory responses and osteoclast function. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212941 [Multi-domain] Cd Length: 56 Bit Score: 43.56 E-value: 1.33e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGS--IGDRSGIFPSNYVKP 268
Cdd:cd12008     2 FVALYDYESRTETDLSFKKGERLqIVNNTEGDWWLAHslTTGQTGYIPSNYVAP 55

Src homology 3 domain of Lyn Protein Tyrosine Kinase; Lyn is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Lyn is expressed in B lymphocytes and myeloid cells. It exhibits both positive and negative regulatory roles in B cell receptor (BCR) signaling. Lyn, as well as Fyn and Blk, promotes B cell activation by phosphorylating ITAMs (immunoreceptor tyr activation motifs) in CD19 and in Ig components of BCR. It negatively regulates signaling by its unique ability to phosphorylate ITIMs (immunoreceptor tyr inhibition motifs) in cell surface receptors like CD22 and CD5. Lyn also plays an important role in G-CSF receptor signaling by phosphorylating a variety of adaptor molecules. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212937 [Multi-domain] Cd Length: 56 Bit Score: 43.44 E-value: 1.33e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMnKDDPDWWQGE--INGVTGLFPSNYV 413
Cdd:cd12004     2 VVALYPYDGIHEDDLSFKKGEKLKVI-EEHGEWWKARslTTKKEGFIPSNYV 52

Src Homology 3 domain of Membrane Protein, Palmitoylated 3 (or MAGUK p55 subfamily member 3); MPP3 is a scaffolding protein that colocalizes with MPP5 and CRB1 at the subdpical region adjacent to adherens junctions and may function in photoreceptor polarity. It interacts with some nectins and regulates their trafficking and processing. Nectins are cell-cell adhesion proteins involved in the establishment apical-basal polarity at cell adhesion sites. It is one of seven vertebrate homologs of the Drosophila Stardust protein, which is required in establishing cell polarity, and it contains two L27 domains followed by the core of three domains characteristic of MAGUK (membrane-associated guanylate kinase) proteins: PDZ, SH3, and guanylate kinase (GuK). The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212972 Cd Length: 62 Bit Score: 43.41 E-value: 1.35e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 349 PSSERATPafhpvCQviamydyaannEDELSFSKGQLINVMNKDDPDWWQ----GEINGVTGLFPS 410
Cdd:cd12039    10 PYEDRAIP-----CQ-----------EAGLPFKRRDILEVVSQDDPTWWQakrvGDTNLRAGLIPS 59

Src Homology 3 domain of fungal peroxisomal membrane protein Pex13p; Pex13p, located in the peroxisomal membrane, contains two transmembrane regions and a C-terminal SH3 domain. It binds to the peroxisomal targeting type I (PTS1) receptor Pex5p and the docking factor Pex14p through its SH3 domain. It is essential for both PTS1 and PTS2 protein import pathways into the peroxisomal matrix. Pex13p binds Pex14p, which contains a PxxP motif, in a classical fashion to the proline-rich ligand binding site of its SH3 domain. It binds the WxxxF/Y motif of Pex5p in a novel site that does not compete with Pex14p binding. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212705 [Multi-domain] Cd Length: 60 Bit Score: 43.42 E-value: 1.38e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 220 ALYPYSSVEPG-DLTFTEGEEILVTQK------DGEWWTGSIGD-RSGIFPSNYV 266
Cdd:cd11771     4 ALYDFTPENPEmELSLKKGDIVAVLSKtdplgrDSEWWKGRTRDgRIGWFPSNYV 58

Second C-terminal Src homology 3 domain of Rho guanine nucleotide exchange factor 37; ARHGEF37 contains a RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. Its specific function is unknown. Its domain architecture is similar to the C-terminal half of DNMBP or Tuba, a cdc42-specific GEF that provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics, and plays an important role in regulating cell junction configuration. GEFs activate small GTPases by exchanging bound GDP for free GTP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212874 Cd Length: 57 Bit Score: 43.36 E-value: 1.38e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDD----PDWWQGEINGVTGLFPSNYV 413
Cdd:cd11941     1 QVVAAYPFTARSKHEVSLQAGQPVTVLEPHDkkgsPEWSLVEVNGQRGYVPSSYL 55

Src Homology 3 domain of Mixed Lineage Kinase 4; MLK4 is a Serine/Threonine Kinase (STK), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. The specific function of MLK4 is yet to be determined. Mutations in the kinase domain of MLK4 have been detected in colorectal cancers. MLK4 contains an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212991 [Multi-domain] Cd Length: 58 Bit Score: 43.39 E-value: 1.38e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTS-----GWWQGELQARgkkrqKGWFPASHV 344
Cdd:cd12058     8 YEASGEDELSLRRGDVVEVLSQDAAvsgddGWWAGKIRHR-----LGIFPANYV 56

First C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212895 [Multi-domain] Cd Length: 54 Bit Score: 43.25 E-value: 1.40e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGE-VHGGRGWFPKSYVKI 185
Cdd:cd11962     1 RAVVLYDYEKDEDNEIELVEGEIVTNIEMvDEDWWMGTnSKGESGLFPSNYVEL 54

Second Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212857 Cd Length: 56 Bit Score: 43.41 E-value: 1.43e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSIG--DRSGIFPSNYVK 267
Cdd:cd11924     2 EAVAQYTFKGDLEVELSFRKGEHIcLIRKVNENWYEGRITgtGRQGIFPASYVQ 55

Fifth Src homology 3 domain (or SH3E) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212928 [Multi-domain] Cd Length: 54 Bit Score: 43.40 E-value: 1.44e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHVKL 346
Cdd:cd11995     9 YTAQNDDELAFSKGQIINVLNKEDPDWWKGELNG-----QVGLFPSNYVKL 54

Ca2+-dependent lipid-binding protein, contains C2 domain [General function prediction only];

Pssm-ID: 227371 [Multi-domain] Cd Length: 1227 Bit Score: 48.99 E-value: 1.44e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  800 IGRLMVHVIEATELKACKP--NGKSNPYceISMGSQSY---TTRTIQDTLNPKWNFNCQFFIKDLyQDVLCLTLFDRDQF 874
Cdd:COG5038    435 IGVVEVKIKSAEGLKKSDStiNGTVDPY--ITVTFSDRvigKTRVKKNTLNPVWNETFYILLNSF-TDPLNLSLYDFNSF 511

                           90       100       110       120
                   ....*....|....*....|....*....|....*....|....*....
gi 1370477838  875 SPDDFLGRTEIPVAKIRtEQESKGPMTRRLLLHEVPTGEvwVRFDLQLF 923
Cdd:COG5038    512 KSDKVVGSTQLDLALLH-QNPVKKNELYEFLRNTKNVGR--LTYDLRFF 557

Second Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212834 [Multi-domain] Cd Length: 55 Bit Score: 43.10 E-value: 1.46e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 132 NLKAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYV 183
Cdd:cd11901     1 NLPAYVKFNYTAEREDELSLVKGTKVIVMEKcSDGWWRGSYNGQVGWFPSNYV 53

Second Src homology 3 domain of Tyrosine kinase substrate with four SH3 domains; Tks4, also called SH3 and PX domain-containing protein 2B (SH3PXD2B) or HOFI, is a Src substrate and scaffolding protein that plays an important role in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. It is required in the formation of functional podosomes, EGF-induced membrane ruffling, and lamellipodia generation. It plays an important role in cellular attachment and cell spreading. Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. It contains an N-terminal Phox homology (PX) domain and four SH3 domains. This model characterizes the second SH3 domain of Tks4. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213009 [Multi-domain] Cd Length: 54 Bit Score: 43.10 E-value: 1.52e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 292 VTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHVK 345
Cdd:cd12076     5 VIYPYTARDQDEINLEKGAVVEVIQKNLEGWWKIRYQG-----KEGWAPASYLK 53

C2 domain found in the Human chromosome 21 open reading frame 25 (C21orf25) protein; The members in this cd are named after the Human C21orf25 which contains a single C2 domain. Several other members contain a C1 domain downstream of the C2 domain. No other information on this protein is currently known. The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176060 [Multi-domain] Cd Length: 126 Bit Score: 45.05 E-value: 1.59e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKACKpnGKSNPYCEISMGS--QSYTTRTIQDTLNPKWNfncQFFIKDLYQD--VLCLTLFDRDQFSPDD 878
Cdd:cd08678     1 LLVKNIKANGLSEAA--GSSNPYCVLEMDEppQKYQSSTQKNTSNPFWD---EHFLFELSPNskELLFEVYDNGKKSDSK 75

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 879 FLGRTEIPVAKIRteqesKGPMTRRLL-LHEVP------TGEVWVRFD 919
Cdd:cd08678    76 FLGLAIVPFDELR-----KNPSGRQIFpLQGRPyegdsvSGSITVEFL 118

C-terminal (or second) Src homology 3 domain of VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and it plays an important role in the development and activation of B and T cells. It is activated by tyrosine phosphorylation to function as a guanine nucleotide exchange factor (GEF) for Rho GTPases following cell surface receptor activation, triggering various effects such as cytoskeletal reorganization, transcription regulation, cell cycle progression, and calcium mobilization. It also serves as a scaffold protein and has been shown to interact with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76, and Syk, among others. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The C-terminal SH3 domain of Vav1 interacts with a wide variety of proteins including cytoskeletal regulators (zyxin), RNA-binding proteins (Sam68), transcriptional regulators, viral proteins, and dynamin 2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212909 [Multi-domain] Cd Length: 54 Bit Score: 43.01 E-value: 1.64e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE--WWTGSIGDRSGIFPSNYVK 267
Cdd:cd11976     4 ARYDFCARDRSELSLKEGDIIKILNKKGQqgWWRGEIYGRVGWFPANYVE 53

Src homology 3 domain of the CAS (Crk-Associated Substrate) scaffolding protein family member, Breast Cancer Anti-estrogen Resistance 1; BCAR1, also called p130cas or CASS1, is the founding member of the CAS family of scaffolding proteins and was originally identified through its ability to associate with Crk. The name BCAR1 was designated because the human gene was identified in a screen for genes that promote resistance to tamoxifen. It is widely expressed and its deletion is lethal in mice. It plays a role in regulating cell motility, survival, proliferation, transformation, cancer progression, and bacterial pathogenesis. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212934 Cd Length: 68 Bit Score: 43.49 E-value: 1.65e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDP---DWWQGEINGVTGLFPSNYVKM 415
Cdd:cd12001     7 ALYDNVAESPDELSFRKGDIMTVLERDTQgldGWWLCSLHGRQGIVPGNRLKI 59

Src homology 3 domain of Src-Like Adaptor Proteins; SLAPs are adaptor proteins with limited similarity to Src family tyrosine kinases. They contain an N-terminal SH3 domain followed by an SH2 domain, and a unique C-terminal sequence. They function in regulating the signaling, ubiquitination, and trafficking of T-cell receptor (TCR) and B-cell receptor (BCR) components. Vertebrates contain two SLAPs, named SLAP (or SLA1) and SLAP2 (or SLA2). SLAP has been shown to interact with the EphA receptor, EpoR, Lck, PDGFR, Syk, CD79a, among others, while SLAP2 interacts with CSF1R. Both SLAPs interact with c-Cbl, LAT, CD247, and Zap70. SLAP modulates TCR surface expression levels as well as surface and total BCR levels. As an adaptor to c-Cbl, SLAP increases the ubiquitination, intracellular retention, and targeted degradation of the BCR complex components. SLAP2 plays a role in c-Cbl-dependent regulation of CSF1R, a tyrosine kinase important for myeloid cell growth and differentiation. The SH3 domain of SLAP forms a complex with v-Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212782 Cd Length: 55 Bit Score: 42.95 E-value: 1.76e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGEWWTG---SIGDRSGIfPSNYV 266
Cdd:cd11848     3 VALGDYPSGGPAELSLRLGEPLTIVSDEGDWWKVlseVTGRESYI-PSVHV 52

Src homology 3 domain of SH3 and multiple ankyrin repeat domains (Shank) proteins; Shank proteins carry scaffolding functions through multiple sites of protein-protein interaction in its domain architecture, including ankyrin (ANK) repeats, a long proline rich region, as well as SH3, PDZ, and SAM domains. They bind a variety of membrane and cytosolic proteins, and exist in alternatively spliced isoforms. They are highly enriched in postsynaptic density (PSD) where they interact with the cytoskeleton and with postsynaptic membrane receptors including NMDA and glutamate receptors. They are crucial in the construction and organization of the PSD and dendritic spines of excitatory synapses. There are three members of this family (Shank1, Shank2, Shank3) which show distinct and cell-type specific patterns of expression. Shank1 is brain-specific; Shank2 is found in neurons, glia, endocrine cells, liver, and kidney; Shank3 is widely expressed. The SH3 domain of Shank binds GRIP, a scaffold protein that binds AMPA receptors and Eph receptors/ligands. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212766 Cd Length: 50 Bit Score: 42.81 E-value: 1.79e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPS 410
Cdd:cd11832     1 YFIAVKSYSPQEEGEISLHKGDRVKVLSIGEGGFWEGSVRGRTGWFPS 48

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase and similar proteins; This subfamily is composed of Rho GTPase activating proteins (GAPs) with similarity to GRAF. Members contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. Although vertebrates harbor four Rho GAPs in the GRAF subfamily including GRAF, GRAF2, GRAF3, and Oligophrenin-1 (OPHN1), only three are included in this model. OPHN1 contains the BAR, PH and GAP domains, but not the C-terminal SH3 domain. GRAF and GRAF2 show GAP activity towards RhoA and Cdc42. GRAF influences Rho-mediated cytoskeletal rearrangements and binds focal adhesion kinase. GRAF2 regulates caspase-activated p21-activated protein kinase-2. The SH3 domain of GRAF and GRAF2 binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212815 [Multi-domain] Cd Length: 54 Bit Score: 42.67 E-value: 1.87e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE--WWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11882     4 ALYACKAEDESELSFEPGQIITNVQPSDEpgWLEGTLNGRTGLIPENYVEF 54

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212777 [Multi-domain] Cd Length: 53 Bit Score: 42.79 E-value: 1.90e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEIL-VTQKDGE-WWTGSIGDRSGIFPSNYV 266
Cdd:cd11843     4 ALYDYEGQESDELSFKAGDILTkLEEEDEQgWCKGRLDGRVGLYPANYV 52

Fourth Src homology 3 domain (or SH3D) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212773 [Multi-domain] Cd Length: 58 Bit Score: 43.10 E-value: 1.91e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHG-GR----GWFPKSYVKI 185
Cdd:cd11839     2 AQVIAPFTATAENQLSLAVGQLVLVRKKSPSgWWEGELQArGKkrqiGWFPANYVKL 58

Third Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212836 [Multi-domain] Cd Length: 59 Bit Score: 43.12 E-value: 1.96e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 221 LYPYSSVEPGDLTFTEGEEILVTQK---DGEWW--TGSIGdRSGIFPSNYV 266
Cdd:cd11903     6 LYPFSSVTEEELNFEKGETMEVIEKpenDPEWWkcKNSRG-QVGLVPKNYV 55

Third Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212858 Cd Length: 57 Bit Score: 43.06 E-value: 1.96e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEI--NGVTGLFPSNYV 413
Cdd:cd11925     4 LALYAYKPQKNDELELRKGEMYRVIEKCQDGWFKGTSlrTGVSGVFPGNYV 54

Src Homology 3 domain of Interleukin-2-inducible T-cell Kinase; ITK (also known as Tsk or Emt) is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation, and the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. ITK is expressed in T-cells and mast cells, and is important in their development and differentiation. Of the three Tec kinases expressed in T-cells, ITK plays the predominant role in T-cell receptor (TCR) signaling. It is activated by phosphorylation upon TCR crosslinking and is involved in the pathway resulting in phospholipase C-gamma1 activation and actin polymerization. It also plays a role in the downstream signaling of the T-cell costimulatory receptor CD28, the T-cell surface receptor CD2, and the chemokine receptor CXCR4. In addition, ITK is crucial for the development of T-helper(Th)2 effector responses. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212841 [Multi-domain] Cd Length: 56 Bit Score: 43.08 E-value: 1.96e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQ-GEINGVTGLFPSNYV 413
Cdd:cd11908     3 VIALYDYQTNDPQELALRYNEEYHLLDSSEIHWWRvQDKNGHEGYVPSSYL 53

Pleckstrin homology domain-containing family G member 5 and 6 pleckstrin homology (PH) domain; PLEKHG5 has a RhoGEF DH/double-homology domain in tandem with a PH domain which is involved in phospholipid binding. PLEKHG5 activates the nuclear factor kappa B (NFKB1) signaling pathway. Mutations in PLEKHG5 are associated with autosomal recessive distal spinal muscular atrophy. PLEKHG6 (also called MyoGEF) has no known function to date. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

Pssm-ID: 270064 Cd Length: 100 Bit Score: 44.14 E-value: 1.97e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 665 RKLLHSG--KLYKTKSNK-ELHGFLFNDFLLLTymvKQfaVSSGSEKLfssksnaqfKMYKTPIFLNEVLVKLPTDPSSd 741
Cdd:cd13244     1 RRLLLEGdlRLKEGKGSKvDVHCFLFTDMLLIC---KP--VKRKKDRL---------KVIRPPYLVDKLVVQELKDPGG- 65

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 1370477838 742 epvFHISHIDR------VYTLRTDNINERTAWVQKIK 772
Cdd:cd13244    66 ---FLLVYLNEfhtavaAYTFQTSSQEDTRRWLDAIR 99

N-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. Its N-terminal SH3 domain binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212879 [Multi-domain] Cd Length: 56 Bit Score: 43.09 E-value: 1.97e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 133 LKAQALCSWTAKKDNHLNFSKHDIITVL--EQQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11946     1 MEAIAKYDFKATADDELSFKRGDILKVLneECDQNWYKAELNGKDGFIPKNYIEM 55

Second Src Homology 3 domain of Nck adaptor proteins; Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212700 [Multi-domain] Cd Length: 53 Bit Score: 42.64 E-value: 2.09e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQK--DGeWWTGSIGDRSGIFPSNYV 266
Cdd:cd11766     1 PAVVKFNYEAQREDELSLRKGDRVLVLEKssDG-WWRGECNGQVGWFPSNYV 51

Third Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212837 [Multi-domain] Cd Length: 57 Bit Score: 42.71 E-value: 2.14e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQEN---WW-FGEVHGGRGWFPKSYVKI 185
Cdd:cd11904     4 QALYPFSSSNDEELNFEKGEVMDVIEKPENdpeWWkCRKANGQVGLVPKNYVTV 57

Src homology 3 domain of Fyn and Yrk Protein Tyrosine Kinases; Fyn and Yrk (Yes-related kinase) are members of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Fyn, together with Lck, plays a critical role in T-cell signal transduction by phosphorylating ITAM (immunoreceptor tyr activation motif) sequences on T-cell receptors, ultimately leading to the proliferation and differentiation of T-cells. In addition, Fyn is involved in the myelination of neurons, and is implicated in Alzheimer's and Parkinson's diseases. Yrk has been detected only in chickens. It is primarily found in neuronal and epithelial cells and in macrophages. It may play a role in inflammation and in response to injury. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212939 [Multi-domain] Cd Length: 56 Bit Score: 42.73 E-value: 2.16e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTG---SIGDrSGIFPSNYVKP 268
Cdd:cd12006     3 FVALYDYEARTEDDLSFHKGEKFqILNSSEGDWWEArslTTGE-TGYIPSNYVAP 56

C2 domain present in Phosphatidylserine decarboxylase (PSD); PSD is involved in the biosynthesis of aminophospholipid by converting phosphatidylserine (PtdSer) to phosphatidylethanolamine (PtdEtn). There is a single C2 domain present and it is thought to confer PtdSer binding motif that is common to PKC and synaptotagmin. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176004 [Multi-domain] Cd Length: 108 Bit Score: 44.17 E-value: 2.17e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSN----PYCEISMGSQSYTTRTIQDTLNPKWNFNCQFFIKDLYQDV-LCLTLFDRDQFS 875
Cdd:cd04039     1 GVVFMEIKSITDLPPLKNMTRTGfdmdPFVIISFGRRVFRTSWRRHTLNPVFNERLAFEVYPHEKNFdIQFKVLDKDKFS 80

                          90       100
                  ....*....|....*....|....*.
gi 1370477838 876 PDDFLGRTEIPVAKIRTEQESKGPMT 901
Cdd:cd04039    81 FNDYVATGSLSVQELLNAAPQPDPET 106

Src Homology 3 domain of fungal peroxisomal membrane protein Pex13p; Pex13p, located in the peroxisomal membrane, contains two transmembrane regions and a C-terminal SH3 domain. It binds to the peroxisomal targeting type I (PTS1) receptor Pex5p and the docking factor Pex14p through its SH3 domain. It is essential for both PTS1 and PTS2 protein import pathways into the peroxisomal matrix. Pex13p binds Pex14p, which contains a PxxP motif, in a classical fashion to the proline-rich ligand binding site of its SH3 domain. It binds the WxxxF/Y motif of Pex5p in a novel site that does not compete with Pex14p binding. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212705 [Multi-domain] Cd Length: 60 Bit Score: 42.65 E-value: 2.21e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1370477838 147 NHLNFSKHDIITVL------EQQENWWFGEVHGGR-GWFPKSYVKI 185
Cdd:cd11771    15 MELSLKKGDIVAVLsktdplGRDSEWWKGRTRDGRiGWFPSNYVEV 60

Src Homology 3 domain of Myosin XV; This subfamily is composed of proteins with similarity to Myosin XVa. Myosin XVa is an unconventional myosin that is critical for the normal growth of mechanosensory stereocilia of inner ear hair cells. Mutations in the myosin XVa gene are associated with nonsyndromic hearing loss. Myosin XVa contains a unique N-terminal extension followed by a motor domain, light chain-binding IQ motifs, and a tail consisting of a pair of MyTH4-FERM tandems separated by a SH3 domain, and a PDZ domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212817 [Multi-domain] Cd Length: 56 Bit Score: 42.70 E-value: 2.41e-05

                          10        20        30
                  ....*....|....*....|....*....|....*....
gi 1370477838 149 LNFSKHDIITVL----EQQENWWFGEVHGGRGWFPKSYV 183
Cdd:cd11884    16 LSFHKGDVIKLLpkegPLDPGWLFGTLDGRSGAFPKEYV 54

First Src homology 3 domain of Tyrosine kinase substrate with five SH3 domains; Tks5, also called SH3 and PX domain-containing protein 2A (SH3PXD2A) or Five SH (FISH), is a scaffolding protein and Src substrate that is localized in podosomes, which are electron-dense structures found in Src-transformed fibroblasts, osteoclasts, macrophages, and some invasive cancer cells. It binds and regulates some members of the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. It is required for podosome formation, degradation of the extracellular matrix, and cancer cell invasion. Tks5 contains an N-terminal Phox homology (PX) domain and five SH3 domains. This model characterizes the first SH3 domain of Tks5. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213007 [Multi-domain] Cd Length: 53 Bit Score: 42.39 E-value: 2.42e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 292 VTSAYVASGSEQLSLAPGQLILILKKNTSGWWqgelqARGKKRQKGWFPASHV 344
Cdd:cd12074     4 VVSNYEKQENSEISLQAGEVVDVIEKNESGWW-----FVSTAEEQGWVPATYL 51

C2 domain second repeat in Ferlin; Ferlins are involved in vesicle fusion events. Ferlins and other proteins, such as Synaptotagmins, are implicated in facilitating the fusion process when cell membranes fuse together. There are six known human Ferlins: Dysferlin (Fer1L1), Otoferlin (Fer1L2), Myoferlin (Fer1L3), Fer1L4, Fer1L5, and Fer1L6. Defects in these genes can lead to a wide range of diseases including muscular dystrophy (dysferlin), deafness (otoferlin), and infertility (fer-1, fertilization factor-1). Structurally they have 6 tandem C2 domains, designated as (C2A-C2F) and a single C-terminal transmembrane domain, though there is a new study that disputes this and claims that there are actually 7 tandem C2 domains with another C2 domain inserted between C2D and C2E. In a subset of them (Dysferlin, Myoferlin, and Fer1) there is an additional conserved domain called DysF. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

Pssm-ID: 175978 [Multi-domain] Cd Length: 111 Bit Score: 44.10 E-value: 2.48e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 805 VHVIEATELkackPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWN----FNCQFFIKDLYQDVLCLTLFDRDQFSPDDFL 880
Cdd:cd04011     8 VRVIEARQL----VGGNIDPVVKVEVGGQKKYTSVKKGTNCPFYNeyffFNFHESPDELFDKIIKISVYDSRSLRSDTLI 83

                          90
                  ....*....|....*
gi 1370477838 881 GRTEIPVAKIRTEQE 895
Cdd:cd04011    84 GSFKLDVGTVYDQPD 98

First Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212854 Cd Length: 55 Bit Score: 42.60 E-value: 2.56e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11921     5 LKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRVGIFPANYVEV 54

Third Src Homology 3 domain (SH3C) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CIN85. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212990 [Multi-domain] Cd Length: 56 Bit Score: 42.58 E-value: 2.69e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQ---ENWWFGEVHGGRGWFPKSYVKII 186
Cdd:cd12057     3 KVLFPYEAQNEDELTIKEGDIVTLISKDcidAGWWEGELNGRRGVFPDNFVKLL 56

Src homology 3 domain of Phospholipase C (PLC) gamma 1; PLCgamma1 is widely expressed and is essential in growth and development. It is activated by the TrkA receptor tyrosine kinase and functions as a key regulator of cell differentiation. It is also the predominant PLCgamma in T cells and is required for T cell and NK cell function. PLCs catalyze the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG). Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212903 Cd Length: 60 Bit Score: 42.67 E-value: 2.72e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRG-WFPKSYVKII 186
Cdd:cd11970     7 KALFDYKAQREDELTFTKNAIIQNVEKQEgGWWRGDYGGKKQlWFPSNYVEEI 59

Src homology 3 domain of Abl Interactor 2; Abi2 is highly expressed in the brain and eye. It regulates actin cytoskeletal reorganization at adherens junctions and dendritic spines, which is important in cell morphogenesis, migration, and cognitive function. Mice deficient with Abi2 show defects in orientation and migration of lens fibers, neuronal migration, dendritic spine morphology, as well as deficits in learning and memory. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212905 [Multi-domain] Cd Length: 61 Bit Score: 42.69 E-value: 2.86e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 216 EEYIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11972     3 EKVVAIYDYTKDKEDELSFQEGAIIYVIKKnDDGWYEGVMNGVTGLFPGNYVE 55

Third Src Homology 3 domain of Nck adaptor proteins; This group contains the third SH3 domain of Nck, the first SH3 domain of Caenorhabditis elegans Ced-2 (Cell death abnormality protein 2), and similar domains. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. Ced-2 is a cell corpse engulfment protein that interacts with Ced-5 in a pathway that regulates the activation of Ced-10, a Rac small GTPase.

Pssm-ID: 212701 [Multi-domain] Cd Length: 56 Bit Score: 42.30 E-value: 3.02e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQK---DGEWW-----TGSIgdrsGIFPSNYVK 267
Cdd:cd11767     3 VALYPFTGENDEELSFEKGERLEIIEKpedDPDWWkarnaLGTT----GLVPRNYVE 55

Src homology 3 domain of Myosins Ie, If, and similar proteins; Myosins Ie (MyoIe) and If (MyoIf) are nonmuscle, unconventional, long tailed, class I myosins containing an N-terminal motor domain and a myosin tail with TH1, TH2, and SH3 domains. MyoIe interacts with the endocytic proteins, dynamin and synaptojanin-1, through its SH3 domain; it may play a role in clathrin-dependent endocytosis. In the kidney, MyoIe is critical for podocyte function and normal glomerular filtration. Mutations in MyoIe is associated with focal segmental glomerulosclerosis, a disease characterized by massive proteinuria and progression to end-stage kidney disease. MyoIf is predominantly expressed in the immune system; it plays a role in immune cell motility and innate immunity. Mutations in MyoIf may be associated with the loss of hearing. The MyoIf gene has also been found to be fused to the MLL (Mixed lineage leukemia) gene in infant acute myeloid leukemias (AML). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212761 [Multi-domain] Cd Length: 53 Bit Score: 42.40 E-value: 3.05e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVL-EQQENWWFGEVHGGRGWFPKSYV 183
Cdd:cd11827     1 QCKALYAYDAQDTDELSFNEGDIIEILkEDPSGWWTGRLRGKEGLFPGNYV 51

C2 domain in Munc13 (mammalian uncoordinated) proteins; fungal group; C2-like domains are thought to be involved in phospholipid binding in a Ca2+ independent manner in both Unc13 and Munc13. Caenorabditis elegans Unc13 has a central domain with sequence similarity to PKC, which includes C1 and C2-related domains. Unc13 binds phorbol esters and DAG with high affinity in a phospholipid manner. Mutations in Unc13 results in abnormal neuronal connections and impairment in cholinergic neurotransmission in the nematode. Munc13 is the mammalian homolog which are expressed in the brain. There are 3 isoforms (Munc13-1, -2, -3) and are thought to play a role in neurotransmitter release and are hypothesized to be high-affinity receptors for phorbol esters. Unc13 and Munc13 contain both C1 and C2 domains. There are two C2 related domains present, one central and one at the carboxyl end. Munc13-1 contains a third C2-like domain. Munc13 interacts with syntaxin, synaptobrevin, and synaptotagmin suggesting a role for these as scaffolding proteins. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

Pssm-ID: 176008 [Multi-domain] Cd Length: 126 Bit Score: 44.18 E-value: 3.13e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 805 VHVIEATELKACKPNGKSNPYCEISMGSQSY---TTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDDFLG 881
Cdd:cd04043     5 IRIVRAENLKADSSNGLSDPYVTLVDTNGKRriaKTRTIYDTLNPRWDEEFELEVPAGEPLWISATVWDRSFVGKHDLCG 84


                  ..
gi 1370477838 882 RT 883
Cdd:cd04043    85 RA 86

First Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212695 [Multi-domain] Cd Length: 57 Bit Score: 42.35 E-value: 3.14e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 362 CQVIamYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEIN--GVTGLFPSNYV 413
Cdd:cd11761     4 CKVL--YSYEAQRPDELTITEGEELEVIEDGDGDGWVKARNksGEVGYVPENYL 55

Second Src Homology 3 domain (SH3B) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CD2AP. SH3B binds to c-Cbl in a site (TPSSRPLR is the core binding motif) distinct from the c-Cbl/SH3A binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212987 [Multi-domain] Cd Length: 55 Bit Score: 42.26 E-value: 3.20e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 221 LYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDRSGIFPSNYVK 267
Cdd:cd12054     6 LFEYVPQNEDELELKVGDIIDINEEVEEgWWSGTLNGKSGLFPSNFVK 53

Src Homology 3 domain of alpha-Pak Interactive eXchange factor; Alpha-PIX, also called Rho guanine nucleotide exchange factor 6 (ARHGEF6) or Cool (Cloned out of Library)-2, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and is localized in dendritic spines where it regulates spine morphogenesis. It controls dendritic length and spine density in the hippocampus. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212993 Cd Length: 58 Bit Score: 42.30 E-value: 3.24e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 133 LKAQALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYVK 184
Cdd:cd12060     2 LVVKARFNFKQTNEDELSVCKGDIIYVTRVEEGgWWEGTLNGKTGWFPSNYVR 54

Src homology 3 domain of Hematopoietic lineage cell-specific protein 1; HS1, also called HCLS1 (hematopoietic cell-specific Lyn substrate 1), is a cortactin homolog expressed specifically in hematopoietic cells. It is an actin regulatory protein that binds the Arp2/3 complex and stabilizes branched actin filaments. It is required for cell spreading and signaling in lymphocytes. It regulates cytoskeletal remodeling that controls lymphocyte trafficking, and it also affects tissue invasion and infiltration of leukemic B cells. Like cortactin, HS1 contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region binds the Arp2/3 complex and F-actin, while the C-terminal region acts as an adaptor or scaffold that can connect varied proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213006 [Multi-domain] Cd Length: 55 Bit Score: 42.13 E-value: 3.41e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd12073     4 VALYDYQGEGDDEISFDPQETITdIEMVDEGWWKGTCHGHRGLFPANYVE 53

C2 domain third repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); plant subset; MCTPs are involved in Ca2+ signaling at the membrane. Plant-MCTPs are composed of a variable N-terminal sequence, four C2 domains, two transmembrane regions (TMRs), and a short C-terminal sequence. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the third C2 repeat, C2C, and has a type-II topology.

Pssm-ID: 175986 [Multi-domain] Cd Length: 150 Bit Score: 44.97 E-value: 3.43e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKACKPNGKSNPYCEISMGSQSYTTRTIQD-TLNPKWNFNCQFFIKDLYQDVLCLTLFDRDQFSPDDFLG 881
Cdd:cd04019     2 LRVTVIEAQDLVPSDKNRVPEVFVKAQLGNQVLRTRPSQTrNGNPSWNEELMFVAAEPFEDHLILSVEDRVGPNKDEPLG 81


                  ....*....
gi 1370477838 882 RTEIPVAKI 890
Cdd:cd04019    82 RAVIPLNDI 90

Third Src Homology 3 domain (SH3C) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CIN85. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212990 [Multi-domain] Cd Length: 56 Bit Score: 42.19 E-value: 3.55e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1370477838 291 QVTSAYVASGSEQLSLAPGQLILILKKNT--SGWWQGELQARgkkrqKGWFPASHVKLL 347
Cdd:cd12057     3 KVLFPYEAQNEDELTIKEGDIVTLISKDCidAGWWEGELNGR-----RGVFPDNFVKLL 56

Src Homology 3 domain of Membrane Protein, Palmitoylated 2 (or MAGUK p55 subfamily member 2); MPP2 is a scaffolding protein that interacts with the non-receptor tyrosine kinase c-Src in epithelial cells to negatively regulate its activity and morphological function. It is one of seven vertebrate homologs of the Drosophila Stardust protein, which is required in establishing cell polarity, and it contains two L27 domains followed by the core of three domains characteristic of MAGUK (membrane-associated guanylate kinase) proteins: PDZ, SH3, and guanylate kinase (GuK). In addition, it also contains the Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212970 Cd Length: 59 Bit Score: 42.25 E-value: 3.62e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 368 YDYAANN-----EDELSFSKGQLINVMNKDDPDWWQGEI--NGVTGLFPS 410
Cdd:cd12037     8 YDPSSDSlipckEAGLKFRAGDLLQIVNQEDPNWWQACHveGGSAGLIPS 57

C-terminal Src Homology 3 domain of the Nebulin family of proteins; Nebulin family proteins contain multiple nebulin repeats, and may contain an N-terminal LIM domain and/or a C-terminal SH3 domain. They have molecular weights ranging from 34 to 900 kD, depending on the number of nebulin repeats, and they all bind actin. They are involved in the regulation of actin filament architecture and function as stabilizers and scaffolds for cytoskeletal structures with which they associate, such as long actin filaments or focal adhesions. Nebulin family proteins that contain a C-terminal SH3 domain include the giant filamentous protein nebulin, nebulette, Lasp1, and Lasp2. Lasp2, also called LIM-nebulette, is an alternatively spliced variant of nebulette. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212723 [Multi-domain] Cd Length: 55 Bit Score: 41.92 E-value: 3.68e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSI---GdRSGIFPSNYVKP 268
Cdd:cd11789     2 YRAMYDYAAADDDEVSFQEGDVIInVEIIDDGWMEGTVqrtG-QSGMLPANYVEL 55

N-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The N-terminal SH3 domain of GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212738 [Multi-domain] Cd Length: 52 Bit Score: 41.96 E-value: 3.70e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVL--EQQENWWFGEVHGGRGWFPKSYV 183
Cdd:cd11804     2 AVAKHDFKATAEDELSFKKGSILKVLnmEDDPNWYKAELDGKEGLIPKNYI 52

Third Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212750 [Multi-domain] Cd Length: 51 Bit Score: 42.01 E-value: 3.88e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11816     3 VARFDFEGEQEDELSFSEGDVItLKEYVGEEWAKGELNGKIGIFPLNFV 51

C-terminal Src Homology 3 domain of LIM and SH3 domain protein 1; Lasp1 is a cytoplasmic protein that binds focal adhesion proteins and is involved in cell signaling, migration, and proliferation. It is overexpressed in several cancer cells including breast, ovarian, bladder, and liver. In cancer cells, it can be found in the nucleus; its degree of nuclear localization correlates with tumor size and poor prognosis. Lasp1 is a 36kD protein containing an N-terminal LIM domain, two nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212867 [Multi-domain] Cd Length: 59 Bit Score: 42.29 E-value: 3.95e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 215 GEEYIALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSI---GDrSGIFPSNYVK 267
Cdd:cd11934     2 GKRYRAVYDYNAADEDEVSFQDGDTIVnVQQIDDGWMYGTVertGD-TGMLPANYVE 57

Third Src Homology 3 domain of SH3 domain containing ring finger 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212859 [Multi-domain] Cd Length: 55 Bit Score: 41.88 E-value: 3.97e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEI--NGVTGLFPSNYV 413
Cdd:cd11926     3 VAIYPYTPRKEDELELRKGEMFLVFERCQDGWFKGTSmhTSKIGVFPGNYV 53

First Src Homology 3 domain (SH3A) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CIN85; SH3A binds to internal proline-rich motifs within the proline-rich region. This intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. SH3A has also been shown to bind ubiquitin and to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic end of the cell adhesion protein CD2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212985 [Multi-domain] Cd Length: 53 Bit Score: 41.80 E-value: 4.34e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:cd12052     2 AIVEFDYKAQHEDELTITVGDIITKIKKDDGGWWEGEIKGR-----RGLFPDNFVR 52

Src homology 3 domain of an unknown subfamily of proteins with similarity to Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212932 [Multi-domain] Cd Length: 56 Bit Score: 41.85 E-value: 4.45e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGD--RSGIFPSNYV 266
Cdd:cd11999     6 AVYDYTGQEPDELSFKAGEELLkVEDEDEQGWCKGVTDggAVGLYPANYV 55

C-terminal (or second) Src homology 3 domain of VAV3 protein; VAV3 is ubiquitously expressed and functions as a phosphorylation-dependent guanine nucleotide exchange factor (GEF) for RhoA, RhoG, and Rac1. It has been implicated to function in the hematopoietic, bone, cerebellar, and cardiovascular systems. VAV3 is essential in axon guidance in neurons that control blood pressure and respiration. It is overexpressed in prostate cancer cells and it plays a role in regulating androgen receptor transcriptional activity. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212911 [Multi-domain] Cd Length: 56 Bit Score: 41.93 E-value: 4.63e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 289 IAQVTSAYVASGSEQLSLAPGQLILI-LKKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:cd11978     2 IAIARYDFCARDMRELSLLKGDVVKIyTKMSTNGWWRGEVNGR-----VGWFPSTYVE 54

Second Src Homology 3 domain of FCH and double SH3 domains protein 1; FCHSD1 has a domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. It has only been characterized in silico and its function is unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212828 Cd Length: 58 Bit Score: 41.88 E-value: 4.74e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQK-----DGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11895     4 ALYSYTGQSPEELSFPEGALIRLLPRaqdgvDDGFWRGEFGGRVGVFPSLLVE 56

Src homology 3 domain of Lck Protein Tyrosine Kinase; Lck is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Lck is expressed in T-cells and natural killer cells. It plays a critical role in T-cell maturation, activation, and T-cell receptor (TCR) signaling. Lck phosphorylates ITAM (immunoreceptor tyr activation motif) sequences on several subunits of TCRs, leading to the activation of different second messenger cascades. Phosphorylated ITAMs serve as binding sites for other signaling factor such as Syk and ZAP-70, leading to their activation and propagation of downstream events. In addition, Lck regulates drug-induced apoptosis by interfering with the mitochondrial death pathway. The apototic role of Lck is independent of its primary function in T-cell signaling. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212938 [Multi-domain] Cd Length: 54 Bit Score: 41.73 E-value: 4.77e-05

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGEWW------TGsigdRSGIFPSNYV 266
Cdd:cd12005     3 VALYSYEPSHDGDLGFEKGEKLRILEQSGEWWkaqsltTG----QEGFIPFNFV 52

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 3 (PACSIN3); PACSIN 3 or Syndapin III (Synaptic dynamin-associated protein III) is expressed ubiquitously and regulates glucose uptake in adipocytes through its role in GLUT1 trafficking. It also modulates the subcellular localization and stimulus-specific function of the cation channel TRPV4. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212930 [Multi-domain] Cd Length: 56 Bit Score: 41.87 E-value: 4.79e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE--WWTGSI-GDRSGIFPSNYVK 267
Cdd:cd11997     6 ALYDYTGQEADELSFKAGEELLKIGEEDEqgWCKGRLlSGRIGLYPANYVE 56

C-terminal (or second) Src homology 3 domain of VAV proteins; VAV proteins function both as cytoplasmic guanine nucleotide exchange factors (GEFs) for Rho GTPases and scaffold proteins and they play important roles in cell signaling by coupling cell surface receptors to various effector functions. They play key roles in processes that require cytoskeletal reorganization including immune synapse formation, phagocytosis, cell spreading, and platelet aggregation, among others. Vertebrates have three VAV proteins (VAV1, VAV2, and VAV3). VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212764 [Multi-domain] Cd Length: 54 Bit Score: 41.85 E-value: 4.82e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 289 IAQVTSAYVASGSEQLSLAPGQLILIL-KKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:cd11830     1 TAKARYDFCARDMRELSLKEGDVVKIYnKKGQQGWWRGEINGR-----IGWFPSTYVE 53

First C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212895 [Multi-domain] Cd Length: 54 Bit Score: 41.70 E-value: 4.96e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTG--SIGdRSGIFPSNYVK 267
Cdd:cd11962     3 VVLYDYEKDEDNEIELVEGEIVTnIEMVDEDWWMGtnSKG-ESGLFPSNYVE 53

Second Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212834 [Multi-domain] Cd Length: 55 Bit Score: 41.56 E-value: 4.99e-05

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                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 222 YPYSSVEPGDLTFTEGEEILVTQK--DGeWWTGSIGDRSGIFPSNYV 266
Cdd:cd11901     8 FNYTAEREDELSLVKGTKVIVMEKcsDG-WWRGSYNGQVGWFPSNYV 53

Src homology 3 domain of Protein arginine N-methyltransferase 2; PRMT2, also called HRMT1L1, belongs to the arginine methyltransferase protein family. It functions as a coactivator to both estrogen receptor alpha (ER-alpha) and androgen receptor (AR), presumably through arginine methylation. The ER-alpha transcription factor is involved in cell proliferation, differentiation, morphogenesis, and apoptosis, and is also implicated in the development and progression of breast cancer. PRMT2 and its variants are upregulated in breast cancer cells and may be involved in modulating the ER-alpha signaling pathway during formation of breast cancer. PRMT2 also plays a role in regulating the function of E2F transcription factors, which are critical cell cycle regulators, by binding to the retinoblastoma gene product (RB). It contains an N-terminal SH3 domain and an AdoMet binding domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212740 [Multi-domain] Cd Length: 53 Bit Score: 41.61 E-value: 5.02e-05

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                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYV 183
Cdd:cd11806     4 AIADFVATDDSQLSFESGDKLLVLRKpSVDWWWAEHNGCCGYIPASHL 51

Src homology 3 domain of Phospholipase C (PLC) gamma; PLC catalyzes the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG) in response to various receptors. Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma catalyzes this reaction in tyrosine kinase-dependent signaling pathways. It is activated and recruited to its substrate at the membrane. Vertebrates contain two forms of PLCgamma, PLCgamma1, which is widely expressed, and PLCgamma2, which is primarily found in haematopoietic cells. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212759 [Multi-domain] Cd Length: 54 Bit Score: 41.55 E-value: 5.06e-05

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELqarGKKRQKgWFPASHVK 345
Cdd:cd11825     8 YRAQRPDELSFCKHAIITNVEKEDGGWWRGDY---GGKKQK-WFPANYVE 53

Fifth Src homology 3 domain (or SH3E) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212774 [Multi-domain] Cd Length: 53 Bit Score: 41.63 E-value: 5.14e-05

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHVKL 346
Cdd:cd11840     8 YTAQNEDELSFQKGDIINVLSKDDPDWWRGELNG-----QTGLFPSNYVEP 53

Src homology 3 domain of Abl Interactor proteins; Abl interactor (Abi) proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. They localize to sites of actin polymerization in epithelial adherens junction and immune synapses, as well as to the leading edge of lamellipodia. Vertebrates contain two Abi proteins, Abi1 and Abi2. Abi1 displays a wide expression pattern while Abi2 is highly expressed in the eye and brain. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212760 [Multi-domain] Cd Length: 52 Bit Score: 41.54 E-value: 5.19e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 295 AYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHV 344
Cdd:cd11826     7 DYTADKDDELSFQEGDIIYVTKKNDDGWYEGVLNGV-----TGLFPGNYV 51

Src Homology 3 domain of Sdc25/Cdc25 guanine nucleotide exchange factors; This subfamily is composed of the Saccharomyces cerevisiae guanine nucleotide exchange factors (GEFs) Sdc25 and Cdc25, and similar proteins. These GEFs regulate Ras by stimulating the GDP/GTP exchange on Ras. Cdc25 is involved in the Ras/PKA pathway that plays an important role in the regulation of metabolism, stress responses, and proliferation, depending on available nutrients and conditions. Proteins in this subfamily contain an N-terminal SH3 domain as well as REM (Ras exchanger motif) and RasGEF domains at the C-terminus. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212816 Cd Length: 55 Bit Score: 41.50 E-value: 5.53e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKD--GeWWTGSIGDRSGI-----FPSNY 265
Cdd:cd11883     3 VALYDFTPKSKNQLSFKAGDIIYVLNKDpsG-WWDGVIISSSGKvkrgwFPSNY 55

Src homology 3 domain of Ubiquitin-associated and SH3 domain-containing proteins, also called TULA (T cell Ubiquitin LigAnd) family of proteins; UBASH3 or TULA proteins are also referred to as Suppressor of T cell receptor Signaling (STS) proteins. They contain an N-terminal UBA domain, a central SH3 domain, and a C-terminal histidine phosphatase domain. They bind c-Cbl through the SH3 domain and to ubiquitin via UBA. In some vertebrates, there are two TULA family proteins, called UBASH3A (also called TULA or STS-2) and UBASH3B (also called TULA-2 or STS-1), which show partly overlapping as well as distinct functions. UBASH3B is widely expressed while UBASH3A is only found in lymphoid cells. UBASH3A facilitates apoptosis induced in T cells through its interaction with the apoptosis-inducing factor AIF. UBASH3B is an active phosphatase while UBASH3A is not. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212725 [Multi-domain] Cd Length: 59 Bit Score: 41.52 E-value: 5.64e-05

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                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1370477838 361 VCQVIamYDYAANNEDELSFSKGQLINVMNKD---DPDWWQGEIN---GVTGLFPSNYV 413
Cdd:cd11791     1 VLRVL--YPYTPQEEDELELVPGDYIYVSPEEldsSSDGWVEGTSwltGCSGLLPENYT 57

First Src homology 3 domain of Tyrosine kinase substrate with four SH3 domains; Tks4, also called SH3 and PX domain-containing protein 2B (SH3PXD2B) or HOFI, is a Src substrate and scaffolding protein that plays an important role in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. It is required in the formation of functional podosomes, EGF-induced membrane ruffling, and lamellipodia generation. It plays an important role in cellular attachment and cell spreading. Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. It contains an N-terminal Phox homology (PX) domain and four SH3 domains. This model characterizes the first SH3 domain of Tks4. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213008 Cd Length: 55 Bit Score: 41.60 E-value: 5.69e-05

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 292 VTSAYVASGSEQLSLAPGQLILILKKNTSGWWqgelqARGKKRQKGWFPAS 342
Cdd:cd12075     5 VVANYQKQESSEISLYVGQVVDIIEKNESGWW-----FVSTADEQGWVPAT 50

Second Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212696 [Multi-domain] Cd Length: 57 Bit Score: 41.61 E-value: 5.70e-05

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQEN-----WWFGEVHGGRGWFP 179
Cdd:cd11762     2 VRALYDYEAQSDEELSFPEGAIIRILRKDDNgvddgWWEGEFNGRVGVFP 51

Third Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212837 [Multi-domain] Cd Length: 57 Bit Score: 41.55 E-value: 5.71e-05

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQK---DGEWWT-GSIGDRSGIFPSNYV 266
Cdd:cd11904     5 ALYPFSSSNDEELNFEKGEVMDVIEKpenDPEWWKcRKANGQVGLVPKNYV 55

Src homology 3 domain of Slit-Robo GTPase Activating Protein 4; srGAP4, also called ARHGAP4, is highly expressed in hematopoietic cells and may play a role in lymphocyte differentiation. It is able to stimulate the GTPase activity of Rac1, Cdc42, and RhoA. In the nervous system, srGAP4 has been detected in differentiating neurites and may be involved in axon and dendritic growth. srGAPs are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212889 [Multi-domain] Cd Length: 55 Bit Score: 41.36 E-value: 5.89e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11956     3 EAVACFDYTGRTAQELSFKRGDVLLLHSKaSSDWWRGEHNGMRGLIPHKYI 53

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 1 (PACSIN1) and PACSIN 2; PACSIN 1 or Syndapin I (Synaptic dynamin-associated protein I) is expressed specifically in the brain and is localized in neurites and synaptic boutons. It binds the brain-specific proteins dynamin I, synaptojanin, synapsin I, and neural Wiskott-Aldrich syndrome protein (nWASP), and functions as a link between the cytoskeletal machinery and synaptic vesicle endocytosis. PACSIN 1 interacts with huntingtin and may be implicated in the neuropathology of Huntington's disease. PACSIN 2 or Syndapin II is expressed ubiquitously and is involved in the regulation of tubulin polymerization. It associates with Golgi membranes and forms a complex with dynamin II which is crucial in promoting vesicle formation from the trans-Golgi network. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212931 [Multi-domain] Cd Length: 56 Bit Score: 41.47 E-value: 5.99e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE--WWTGSI-GDRSGIFPSNYVKP 268
Cdd:cd11998     5 ALYDYDGQEQDELSFKAGDELTKLEDEDEqgWCKGRLdSGQVGLYPANYVEP 56

First Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212852 [Multi-domain] Cd Length: 55 Bit Score: 41.49 E-value: 6.02e-05

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKII 186
Cdd:cd11919     2 PARAKFDFKAQTLKELPLQKGDIVYIYKQiDQNWYEGEHHGRVGIFPRSYIELL 55

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member, Neural precursor cell Expressed, Developmentally Down-regulated 9; NEDD9 is also called human enhancer of filamentation 1 (HEF1) or CAS-L (Crk-associated substrate in lymphocyte). It was first described as a gene predominantly expressed in early embryonic brain, and was also isolated from a screen of human proteins that regulate filamentous budding in yeast, and as a tyrosine phosphorylated protein in lymphocytes. It promotes metastasis in different solid tumors. NEDD9 localizes in focal adhesions and associates with FAK and Abl kinase. It also interacts with SMAD3 and the proteasomal machinery which allows its rapid turnover; these interactions are not shared by other CAS proteins. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212935 Cd Length: 57 Bit Score: 41.51 E-value: 6.43e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQ----ENWWFGEVHGGRGWFPKSYVKII 186
Cdd:cd12002     2 ARALYDNVPECAEELAFRKGDILTVIEQNtgglEGWWLCSLHGRQGIAPGNRLKLL 57

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF16 and ARHGEF26; ARHGEF16, also called ephexin-4, acts as a GEF for RhoG, activating it by exchanging bound GDP for free GTP. RhoG is a small GTPase that is a crucial regulator of Rac in migrating cells. ARHGEF16 interacts directly with the ephrin receptor EphA2 and mediates cell migration and invasion in breast cancer cells by activating RhoG. ARHGEF26, also called SGEF (SH3 domain-containing guanine exchange factor), also activates RhoG. It is highly expressed in liver and may play a role in regulating membrane dynamics. ARHGEF16 and ARHGEF26 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212871 Cd Length: 55 Bit Score: 41.37 E-value: 6.48e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 291 QVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGElqaRGKKRQKGWFPASHVK 345
Cdd:cd11938     3 EIIKAYTAKQPDELSLQQADVVLVLQTESDGWYYGE---RLRDGERGWFPSSCAK 54

C2 domain found in the Human KIAA0528 cDNA clone; The members of this CD are named after the Human KIAA0528 cDNA clone. All members here contain a single C2 repeat. No other information on this protein is currently known. The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176070 [Multi-domain] Cd Length: 110 Bit Score: 43.06 E-value: 6.63e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKAC-KPNGKSNPYCEISMGSQSYTTRTIQDTLNPKWnfNCQFFI-----KDLYQDVLCLTLFDRDQFSP 876
Cdd:cd08688     1 LKVRVVAARDLPVMdRSSDLTDAFVEVKFGSTTYKTDVVKKSLNPVW--NSEWFRfevddEELQDEPLQIRVMDHDTYSA 78


                  ....*....
gi 1370477838 877 DDFLGRTEI 885
Cdd:cd08688    79 NDAIGKVYI 87

N-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The N-terminal SH3 domain of the related protein GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212881 [Multi-domain] Cd Length: 54 Bit Score: 41.34 E-value: 6.63e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVT--QKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11948     1 EAVALYSFQATESDELPFQKGDILKILnmEDDQNWYKAELQGREGYIPKNYIK 53

Second Src homology 3 domain of Tyrosine kinase substrate with four SH3 domains; Tks4, also called SH3 and PX domain-containing protein 2B (SH3PXD2B) or HOFI, is a Src substrate and scaffolding protein that plays an important role in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. It is required in the formation of functional podosomes, EGF-induced membrane ruffling, and lamellipodia generation. It plays an important role in cellular attachment and cell spreading. Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. It contains an N-terminal Phox homology (PX) domain and four SH3 domains. This model characterizes the second SH3 domain of Tks4. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213009 [Multi-domain] Cd Length: 54 Bit Score: 41.17 E-value: 6.82e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 216 EEYIALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDRSGIFPSNYVK 267
Cdd:cd12076     1 EKYTVIYPYTARDQDEINLEKGAVVEVIQKNLEgWWKIRYQGKEGWAPASYLK 53

Src Homology 3 domain of Nephrocystin (or Nephrocystin-1); Nephrocystin contains an SH3 domain involved in signaling pathways that regulate cell adhesion and cytoskeletal organization. It is a protein that in humans is associated with juvenile nephronophthisis, an inherited kidney disease characterized by renal fibrosis that lead to chronic renal failure in children. It is localized in cell-cell junctions in renal duct cells, and is known to interact with Ack1, an activated Cdc42-associated kinase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212704 [Multi-domain] Cd Length: 54 Bit Score: 41.14 E-value: 6.82e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGE-VHGGRGWFPKSYVKI 185
Cdd:cd11770     4 ALSDFQAEQEGDLSFKKGEVLRIISKRADgWWLAEnSKGNRGLVPKTYLKV 54

Second Src Homology 3 domain of Bzz1 and similar domains; Bzz1 (or Bzz1p) is a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Together with other proteins, it induces membrane scission in yeast. Bzz1 contains an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a central coiled-coil, and two C-terminal SH3 domains. This model represents the second C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212712 [Multi-domain] Cd Length: 51 Bit Score: 41.33 E-value: 7.04e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQEN--WWFGEVHGGRGWFPKSY 182
Cdd:cd11778     1 YVEALYDYEAQGDDEISIRVGDRIAVIRGDDGsgWTYGEINGVKGLFPTSY 51

Src homology 3 domain of SH3 protein interacting with Nck, 90 kDa (SPIN90); SPIN90 is also called NCK interacting protein with SH3 domain (NCKIPSD), Dia-interacting protein (DIP), 54 kDa vimentin-interacting protein (VIP54), or WASP-interacting SH3-domain protein (WISH). It is an F-actin binding protein that regulates actin polymerization and endocytosis. It associates with the Arp2/3 complex near actin filaments and determines filament localization at the leading edge of lamellipodia. SPIN90 is expressed in the early stages of neuronal differentiation and plays a role in regulating growth cone dynamics and neurite outgrowth. It also interacts with IRSp53 and regulates cell motility by playing a role in the formation of membrane protrusions. SPIN90 contains an N-terminal SH3 domain, a proline-rich domain, and a C-terminal VCA (verprolin-homology and cofilin-like acidic) domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212783 [Multi-domain] Cd Length: 53 Bit Score: 41.15 E-value: 7.25e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQ-GEINGVTGLFPSNYVK 414
Cdd:cd11849     4 ALYDFKSAEPNTLSFSEGETFLLLERSNAHWWLvTNHSGETGYVPANYVK 53

Third Src Homology 3 domain of SH3 domain containing ring finger 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212859 [Multi-domain] Cd Length: 55 Bit Score: 41.11 E-value: 7.37e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK--DGeWWTGSIGDRS--GIFPSNYVKP 268
Cdd:cd11926     2 YVAIYPYTPRKEDELELRKGEMFLVFERcqDG-WFKGTSMHTSkiGVFPGNYVAP 55

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing proteins; ASAPs are Arf GTPase activating proteins (GAPs) and they function in regulating cell growth, migration, and invasion. They contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. Vertebrates contain at least three members, ASAP1, ASAP2, and ASAP3, but some ASAP3 proteins do not seem to harbor a C-terminal SH3 domain. ASAP1 and ASAP2 show GTPase activating protein (GAP) activity towards Arf1 and Arf5. They do not show GAP activity towards Arf6, but are able to mediate Arf6 signaling by binding stably to GTP-Arf6. ASAP3 is an Arf6-specific GAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212755 [Multi-domain] Cd Length: 53 Bit Score: 41.15 E-value: 7.47e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVL-EQQENWWFGEVHGG---RGWFPKSY 182
Cdd:cd11821     1 RVRALYDCQADNDDELTFSEGEIIVVTgEEDDEWWEGHIEGDpsrRGVFPVSF 53

Variant SH3 domain;

Pssm-ID: 434066 [Multi-domain] Cd Length: 49 Bit Score: 41.06 E-value: 7.68e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 295 AYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:pfam14604   4 PYEPKDDDELSLQRGDVITVIEESEDGWWEGINTGR-----TGLVPANYVE 49

Second Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212835 [Multi-domain] Cd Length: 55 Bit Score: 41.14 E-value: 7.71e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1370477838 140 SWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYV 183
Cdd:cd11902     8 AYVAEREDELSLVKGSRVTVMEKcSDGWWRGSYNGQIGWFPSNYV 52

Src Homology 3 domain of Myosin XV; This subfamily is composed of proteins with similarity to Myosin XVa. Myosin XVa is an unconventional myosin that is critical for the normal growth of mechanosensory stereocilia of inner ear hair cells. Mutations in the myosin XVa gene are associated with nonsyndromic hearing loss. Myosin XVa contains a unique N-terminal extension followed by a motor domain, light chain-binding IQ motifs, and a tail consisting of a pair of MyTH4-FERM tandems separated by a SH3 domain, and a PDZ domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212817 [Multi-domain] Cd Length: 56 Bit Score: 41.16 E-value: 7.76e-05

                          10        20        30
                  ....*....|....*....|....*....|..
gi 1370477838  15 IYSVDEKTVGEPGWLYGSFQGNFGWFPCNYVE 46
Cdd:cd11884    24 IKLLPKEGPLDPGWLFGTLDGRSGAFPKEYVQ 55

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the third SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212714 [Multi-domain] Cd Length: 55 Bit Score: 41.13 E-value: 7.85e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK--DGeWWTGSIGdRS---GIFPSNYVKP 268
Cdd:cd11780     2 YRALYSYTPQNEDELELREGDIVYVMEKcdDG-WFVGTSE-RTglfGTFPGNYVAR 55

Src homology 3 domain of Rho GTPase-activating proteins 32 and 33, and similar proteins; Members of this family contain N-terminal PX and Src Homology 3 (SH3) domains, a central Rho GAP domain, and C-terminal extensions. RhoGAPs (or ARHGAPs) bind to Rho proteins and enhance the hydrolysis rates of bound GTP. ARHGAP32 is also called RICS, PX-RICS, p250GAP, or p200RhoGAP. It is a Rho GTPase-activating protein for Cdc42 and Rac1, and is implicated in the regulation of postsynaptic signaling and neurite outgrowth. PX-RICS, a variant of RICS that contain PX and SH3 domains, is the main isoform expressed during neural development. It is involved in neural functions including axon and dendrite extension, postnatal remodeling, and fine-tuning of neural circuits during early brain development. ARHGAP33, also called sorting nexin 26 or TCGAP (Tc10/CDC42 GTPase-activating protein), is widely expressed in the brain where it is involved in regulating the outgrowth of axons and dendrites and is regulated by the protein tyrosine kinase Fyn. It is translocated to the plasma membrane in adipocytes in response to insulin and may be involved in the regulation of insulin-stimulated glucose transport. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212769 [Multi-domain] Cd Length: 54 Bit Score: 40.90 E-value: 8.49e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 370 YAANNEDELSFSKGQLINVMN---KDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11835     8 YTAQAPDELSLEVGDIVSVIDmppPEESTWWRGKKGFQVGFFPSECV 54

Third Src homology 3 domain (or SH3C) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212924 Cd Length: 52 Bit Score: 41.12 E-value: 8.66e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11991     4 AMYTYESNEQGDLTFQQGDVILVTKKDGDWWTGTVGDKTGVFPSNYVR 51

Src Homology 3 domain of Brain-specific Angiogenesis Inhibitor 1-Associated Protein 2-Like 1, also called Insulin Receptor Tyrosine Kinase Substrate (IRTKS); BAIAP2L1 or IRTKS is widely expressed, serves as a substrate for the insulin receptor, and binds the small GTPase Rac. It plays a role in regulating the actin cytoskeleton and colocalizes with F-actin, cortactin, VASP, and vinculin. BAIAP2L1 expression leads to the formation of short actin bundles, distinct from filopodia-like protrusions induced by the expression of the related protein IRSp53. IRTKS mediates the recruitment of effector proteins Tir and EspFu, which regulate host cell actin reorganization, to bacterial attachment sites. It contains an N-terminal IMD or Inverse-Bin/Amphiphysin/Rvs (I-BAR) domain, an SH3 domain, and a WASP homology 2 (WH2) actin-binding motif at the C-terminus. The SH3 domain of IRTKS has been shown to bind the proline-rich C-terminus of EspFu. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212846 Cd Length: 58 Bit Score: 41.05 E-value: 9.29e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1370477838 149 LNFSKHDIITVL--EQQENWWFGE--VHGGRGWFPKSYVK 184
Cdd:cd11913    18 LSFAQGDVITLLipEEKDGWLYGEhdTTKARGWFPSSYTR 57

Second or C-terminal Src homology 3 domain of the p47phox subunit of NADPH oxidase, also called Neutrophil Cytosolic Factor 1; p47phox, or NCF1, is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox), which plays a key role in the ability of phagocytes to defend against bacterial infections. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p47phox is required for activation of NADH oxidase and plays a role in translocation. It contains an N-terminal Phox homology (PX) domain, tandem SH3 domains (N-SH3 and C-SH3), a polybasic/autoinhibitory region, and a C-terminal proline-rich region (PRR). This model characterizes the second SH3 domain (or C-SH3) of p47phox. In its inactive state, the tandem SH3 domains interact intramolecularly with the autoinhibitory region; upon activation, the tandem SH3 domains are exposed through a conformational change, resulting in their binding to the PRR of p22phox and the activation of NADPH oxidase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212955 [Multi-domain] Cd Length: 53 Bit Score: 40.98 E-value: 9.62e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK--DGeWWTGSIGDRSGIFPSNYVK 267
Cdd:cd12022     2 YITIKAYTAVEEDELTLLEGEAIEVIHKllDG-WWVVRKGEVTGYFPSMYLQ 52

First Src Homology 3 domain (SH3A) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CIN85; SH3A binds to internal proline-rich motifs within the proline-rich region. This intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. SH3A has also been shown to bind ubiquitin and to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic end of the cell adhesion protein CD2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212985 [Multi-domain] Cd Length: 53 Bit Score: 41.03 E-value: 9.72e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1370477838 141 WTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYVK 184
Cdd:cd12052     8 YKAQHEDELTITVGDIITKIKKDDGgWWEGEIKGRRGLFPDNFVR 52

Src homology 3 domain of Src-Like Adaptor Protein 2; SLAP2 plays a role in c-Cbl-dependent regulation of CSF1R, a tyrosine kinase important for myeloid cell growth and differentiation. It has been shown to interact with CSF1R, c-Cbl, LAT, CD247, and Zap70. SLAPs are adaptor proteins with limited similarity to Src family tyrosine kinases. They contain an N-terminal SH3 domain followed by an SH2 domain, and a unique C-terminal sequence. They function in regulating the signaling, ubiquitination, and trafficking of T-cell receptor (TCR) and B-cell receptor (BCR) components. The SH3 domain of SLAP forms a complex with v-Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212944 Cd Length: 55 Bit Score: 40.88 E-value: 1.03e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGEWWT--GSIGDRSGIFPSNYV 266
Cdd:cd12011     3 VALCNFPSGGPTELSIRMGEQLTILSEDGDWWKvsSAVTGRECYIPSNYV 52

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. Also included in this subfamily is the second C-terminal SH3 domain of Rho guanine nucleotide exchange factor 37 (ARHGEF37), whose function is still unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212734 [Multi-domain] Cd Length: 57 Bit Score: 40.82 E-value: 1.05e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQE-----NWWFGEVHGGRGWFPKSY 182
Cdd:cd11800     4 ALYTFEARSPGELSVTEGQVVTVLEKHDlkgnpEWWLVEDRGKQGYVPSNY 54

First Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212707 [Multi-domain] Cd Length: 57 Bit Score: 40.87 E-value: 1.06e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRS-------GIFPSNY 265
Cdd:cd11773     2 YKALYDYEPQTEDELTIQEDDILYLLEKsDDDWWKVKLKVNSsdddepvGLVPATY 57

Src homology 3 domain of Growth Arrest Specific protein 7; GAS7 is mainly expressed in the brain and is required for neurite outgrowth. It may also play a role in the protection and migration of embryonic stem cells. Treatment-related acute myeloid leukemia (AML) has been reported resulting from mixed-lineage leukemia (MLL)-GAS7 translocations as a complication of primary cancer treatment. GAS7 contains an N-terminal SH3 domain, followed by a WW domain, and a central F-BAR domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212763 [Multi-domain] Cd Length: 52 Bit Score: 40.57 E-value: 1.10e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSvEPGD--LTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11829     4 TLYAFTG-EQHQqgLSFEAGELIRVLQApDGGWWEGEKDGLRGWFPASYV 52

Src homology 3 domain of Proline-Serine-Threonine Phosphatase-Interacting Protein 1; PSTPIP1, also called CD2 Binding Protein 1 (CD2BP1), is mainly expressed in hematopoietic cells. It is a binding partner of the cell surface receptor CD2 and PTP-PEST, a tyrosine phosphatase which functions in cell motility and Rac1 regulation. It also plays a role in the activation of the Wiskott-Aldrich syndrome protein (WASP), which couples actin rearrangement and T cell activation. Mutations in the gene encoding PSTPIP1 cause the autoinflammatory disorder known as PAPA (pyogenic sterile arthritis, pyoderma gangrenosum, and acne) syndrome. PSTPIP1 contains an N-terminal F-BAR domain, PEST motifs, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212758 [Multi-domain] Cd Length: 53 Bit Score: 40.43 E-value: 1.14e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGElqargKKRQKGWFPASHVKL 346
Cdd:cd11824     2 YSVLYDYTAQEDDELSISKGDVVAVIEKGEDGWWTVE-----RNGQKGLVPGTYLEK 53

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF5 and ARHGEF19; ARHGEF5, also called ephexin-3 or TIM (Transforming immortalized mammary oncogene), is a potent activator of RhoA and it plays roles in regulating cell shape, adhesion, and migration. It binds to the SH3 domain of Src and is involved in regulating Src-induced podosome formation. ARHGEF19, also called ephexin-2 or WGEF (weak-similarity GEF), is highly expressed in the intestine, liver, heart and kidney. It activates RhoA, Cdc42, and Rac 1, and has been shown to activate RhoA in the Wnt-PCP (planar cell polarity) pathway. It is involved in the regulation of cell polarity and cytoskeletal reorganization. ARHGEF5 and ARHGEF19 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212873 Cd Length: 55 Bit Score: 40.55 E-value: 1.14e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 291 QVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGelqARGKKRQKGWFPASHVKL 346
Cdd:cd11940     3 QCIRSYKAQENDELTLEKADIIMVRQQSSDGWLEG---VRLSDGERGWFPQSHVEE 55

C2 domain (first repeat) of Ras GTPase activating proteins (GAPs); RasGAPs suppress Ras function by enhancing the GTPase activity of Ras proteins resulting in the inactive GDP-bound form of Ras. In this way it can control cellular proliferation and differentiation. The proteins here all contain either a single C2 domain or two tandem C2 domains, a Ras-GAP domain, and a pleckstrin homology (PH)-like domain. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. Members here have a type-I topology.

Pssm-ID: 176029 [Multi-domain] Cd Length: 117 Bit Score: 42.64 E-value: 1.17e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKackPNGKSNPYCEISMGS-QSYTTRTIQDtLNPKWNFncQFFIKDLYQDV----LCLTLFDRDQFSPD 877
Cdd:cd08383     2 LRLRILEAKNLP---SKGTRDPYCTVSLDQvEVARTKTVEK-LNPFWGE--EFVFDDPPPDVtfftLSFYNKDKRSKDRD 75

                          90       100       110
                  ....*....|....*....|....*....|....*...
gi 1370477838 878 DFLGRTEipvakIRTEQESKGPMTRRLLLHEVPTGEVW 915
Cdd:cd08383    76 IVIGKVA-----LSKLDLGQGKDEWFPLTPVDPDSEVQ 108

Fourth Src homology 3 domain (or SH3D) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fourth SH3 domain (or SH3D) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212927 Cd Length: 59 Bit Score: 40.69 E-value: 1.21e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHG-----GRGWFPKSYVKII 186
Cdd:cd11994     2 AQVTTAYVASGVEQLSLSPGQLILILKKNSSgWWLGELQArgkkrQKGWFPASHVKLL 59

Src homology 3 domain of Slit-Robo GTPase Activating Protein 4; srGAP4, also called ARHGAP4, is highly expressed in hematopoietic cells and may play a role in lymphocyte differentiation. It is able to stimulate the GTPase activity of Rac1, Cdc42, and RhoA. In the nervous system, srGAP4 has been detected in differentiating neurites and may be involved in axon and dendritic growth. srGAPs are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212889 [Multi-domain] Cd Length: 55 Bit Score: 40.59 E-value: 1.23e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 133 LKAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11956     2 VEAVACFDYTGRTAQELSFKRGDVLLLHSKaSSDWWRGEHNGMRGLIPHKYISV 55

Second Src homology 3 domain (or SH3B) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212771 [Multi-domain] Cd Length: 53 Bit Score: 40.43 E-value: 1.25e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 291 QVTSAYV--ASGSEQLSLAPGQLILILKKNTSgWWQGELQargkKRQKGWFPASHVKL 346
Cdd:cd11837     1 TATALYPwrAKKENHLSFAKGDIITVLEQQEM-WWFGELE----GGEEGWFPKSYVKE 53

Third Src Homology 3 domain (SH3C) of CD2-associated protein and similar proteins; This subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212808 [Multi-domain] Cd Length: 55 Bit Score: 40.41 E-value: 1.27e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNT--SGWWQGELQARgkkrqKGWFPASHVKL 346
Cdd:cd11875     2 ARVLFDYEAENEDELTLREGDIVTILSKDCedKGWWKGELNGK-----RGVFPDNFVEP 55

Second Src Homology 3 domain (SH3B) of CD2-associated protein and similar proteins; This subfamily is composed of the second SH3 domain (SH3B) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3B of both proteins have been shown to bind to Cbl. In the case of CD2AP, its SH3B binds to Cbl at a site distinct from the c-Cbl/SH3A binding site. The CIN85 SH3B also binds ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212807 [Multi-domain] Cd Length: 53 Bit Score: 40.39 E-value: 1.28e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11874     1 RCKVLFSYTPQNEDELELKVGDTIEVLGEvEEGWWEGKLNGKVGVFPSNFVKE 53

Src Homology 3 domain of Sorting nexin 18; SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. It binds FIP5 and is required for apical lumen formation. It may also play a role in axonal elongation. SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX18 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212830 [Multi-domain] Cd Length: 55 Bit Score: 40.36 E-value: 1.32e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEIN--GVTGLFPSNYVKM 415
Cdd:cd11897     4 ALYDFRSENPGEISLREHEVLSLCSEQDIEGWLEGVNsrGDRGLFPASYVEV 55

Src homology 3 domain of Abl Interactor 1; Abi1, also called e3B1, is a central regulator of actin cytoskeletal reorganization through interactions with many protein complexes. It is part of WAVE, a nucleation-promoting factor complex, that links Rac 1 activation to actin polymerization causing lamellipodia protrusion at the plasma membrane. Abi1 interact with formins to promote protrusions at the leading edge of motile cells. It also is a target of alpha4 integrin, regulating membrane protrusions at sites of integrin engagement. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212904 [Multi-domain] Cd Length: 59 Bit Score: 40.77 E-value: 1.38e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11971     3 VAIYDYSKDKDDELSFMEGAIIYVIKKnDDGWYEGVCNGVTGLFPGNYVE 52

C-terminal (or second) Src Homology 3 domain of the p67phox subunit of NADPH oxidase; p67phox, also called Neutrophil cytosol factor 2 (NCF-2), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox plays a regulatory role and contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. It binds, via its C-terminal SH3 domain, to a proline-rich region of p47phox and upon activation, this complex assembles with flavocytochrome b558, the Nox2-p22phox heterodimer. Concurrently, RacGTP translocates to the membrane and interacts with the TPR domain of p67phox, which leads to the activation of NADPH oxidase. The PB1 domain of p67phox binds to its partner PB1 domain in p40phox, and this facilitates the assembly of p47phox-p67phox at the membrane. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212979 [Multi-domain] Cd Length: 53 Bit Score: 40.56 E-value: 1.41e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd12046     4 ALFSYEASQPEDLEFQKGDVILVLSKvNEDWLEGQCKGKIGIFPSAFVE 52

Third Src homology 3 domain of Tyrosine kinase substrate (Tks) proteins; Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Vertebrates contain two Tks proteins, Tks4 (Tyr kinase substrate with four SH3 domains) and Tks5 (Tyr kinase substrate with five SH3 domains), which display partially overlapping but non-redundant functions. Both associate with the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. Tks5 interacts with N-WASP and Nck, while Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. Tks proteins contain an N-terminal Phox homology (PX) domain and four or five SH3 domains. This model characterizes the third SH3 domain of Tks proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212950 Cd Length: 53 Bit Score: 40.51 E-value: 1.45e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1370477838 369 DYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd12017     7 EFQATIQDGISFQKGQKVEVIDKNPSGWWYVKIDGKEGWAPSSYI 51

First Src Homology 3 domain of Bud emergence protein 1 and similar domains; Members of this subfamily bear similarity to Saccharomyces cerevisiae Bem1p, containing two Src Homology 3 (SH3) domains at the N-terminus, a central PX domain, and a C-terminal PB1 domain. Bem1p is a scaffolding protein that is critical for proper Cdc42p activation during bud formation in yeast. During budding and mating, Bem1p migrates to the plasma membrane where it can serve as an adaptor for Cdc42p and some other proteins. Bem1p also functions as an effector of the G1 cyclin Cln3p and the cyclin-dependent kinase Cdc28p in promoting vacuolar fusion. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212811 [Multi-domain] Cd Length: 54 Bit Score: 40.35 E-value: 1.49e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 364 VI-AMYDYAANNEDELSFSKGQLINVMNKDDPD-WWQGE--INGVTGLFPSNY 412
Cdd:cd11878     1 VIrALYDYRAQTPGELSFSKGDFFHVIGEEDQGeWYEATnpVTGKRGLVPKSY 53

Src homology 3 domain of Cortactin; Cortactin was originally identified as a substrate of Src kinase. It is an actin regulatory protein that binds to the Arp2/3 complex and stabilizes branched actin filaments. It is involved in cellular processes that affect cell motility, adhesion, migration, endocytosis, and invasion. It is expressed ubiquitously except in hematopoietic cells, where the homolog hematopoietic lineage cell-specific 1 (HS1) is expressed instead. Cortactin contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region interacts with the Arp2/3 complex and F-actin, and is crucial in regulating branched actin assembly. Cortactin also serves as a scaffold and provides a bridge to the actin cytoskeleton for membrane trafficking and signaling proteins that bind to its SH3 domain. Binding partners for the SH3 domain of cortactin include dynamin2, N-WASp, MIM, FGD1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212892 [Multi-domain] Cd Length: 53 Bit Score: 40.09 E-value: 1.51e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11959     3 VALYDYQAADDDEISFDPDDIITnIEMIDEGWWRGVCRGKYGLFPANYVE 52

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member, Embryonal Fyn-associated Substrate; EFS is also called HEFS, CASS3 (Cas scaffolding protein family member 3) or SIN (Src-interacting protein). It was identified based on interactions with the Src kinases, Fyn and Yes. It plays a role in thymocyte development and acts as a negative regulator of T cell proliferation. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212936 Cd Length: 62 Bit Score: 40.64 E-value: 1.55e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQE----NWWFGEVHGGRGWFPKSYVKIIP 187
Cdd:cd12003     3 AKALYDNAAESPEELSFRRGDVLMVLKREHgslpGWWLCSLHGQQGIAPANRLRLLP 59

Src homology 3 domain of Type I fungal Myosins; Type I myosins (myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Saccharomyces cerevisiae has two myosins-I, Myo3 and Myo5, which are involved in endocytosis and the polarization of the actin cytoskeleton. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212792 [Multi-domain] Cd Length: 55 Bit Score: 40.45 E-value: 1.60e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWqgeLQARGKKRQKGWFPASHVKL 346
Cdd:cd11858     8 FAGSVANELSLKKDDIVYIVQKEDNGWW---LAKKLDESKEGWVPAAYLEE 55

Src homology 3 domain of SH3 and multiple ankyrin repeat domains protein 1; Shank1, also called SSTRIP (Somatostatin receptor-interacting protein), is a brain-specific protein that plays a role in the construction of postsynaptic density (PSD) and the maturation of dendritic spines. Mice deficient in Shank1 show altered PSD composition, thinner PSDs, smaller dendritic spines, and weaker basal synaptic transmission, although synaptic plasticity is normal. They show increased anxiety and impaired fear memory, but also show better spatial learning. Shank proteins carry scaffolding functions through multiple sites of protein-protein interaction in its domain architecture, including ankyrin (ANK) repeats, a long proline rich region, as well as SH3, PDZ, and SAM domains. The SH3 domain of Shank binds GRIP, a scaffold protein that binds AMPA receptors and Eph receptors/ligands. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212915 [Multi-domain] Cd Length: 52 Bit Score: 40.38 E-value: 1.61e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILV-TQKDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11982     3 FMAVKPYQSQAEGEISLSKGEKIKVlSVGEGGFWEGQVKGRVGWFPSDCV 52

Src Homology 3 domain of C-terminal Src kinase; CSK is a cytoplasmic (or nonreceptor) tyr kinase containing the Src homology domains, SH3 and SH2, N-terminal to the catalytic tyr kinase domain. They negatively regulate the activity of Src kinases that are anchored to the plasma membrane. To inhibit Src kinases, CSK is translocated to the membrane via binding to specific transmembrane proteins, G-proteins, or adaptor proteins near the membrane. CSK catalyzes the tyr phosphorylation of the regulatory C-terminal tail of Src kinases, resulting in their inactivation. It is expressed in a wide variety of tissues and plays a role, as a regulator of Src, in cell proliferation, survival, and differentiation, and consequently, in cancer development and progression. In addition, CSK also shows Src-independent functions. It is a critical component in G-protein signaling, and plays a role in cytoskeletal reorganization and cell migration. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212703 [Multi-domain] Cd Length: 57 Bit Score: 40.36 E-value: 1.61e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 215 GEEYIALYPYSSVEPGDLTFTEGEEILVTQ--KDGEWWTGSIGD-RSGIFPSNYVK 267
Cdd:cd11769     1 GTECIAKYNFNGASEEDLPFKKGDILTIVAvtKDPNWYKAKNKDgREGMIPANYVQ 56

Src homology 3 domain of Hematopoietic lineage cell-specific protein 1; HS1, also called HCLS1 (hematopoietic cell-specific Lyn substrate 1), is a cortactin homolog expressed specifically in hematopoietic cells. It is an actin regulatory protein that binds the Arp2/3 complex and stabilizes branched actin filaments. It is required for cell spreading and signaling in lymphocytes. It regulates cytoskeletal remodeling that controls lymphocyte trafficking, and it also affects tissue invasion and infiltration of leukemic B cells. Like cortactin, HS1 contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region binds the Arp2/3 complex and F-actin, while the C-terminal region acts as an adaptor or scaffold that can connect varied proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213006 [Multi-domain] Cd Length: 55 Bit Score: 40.20 E-value: 1.63e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGelQARGKkrqKGWFPASHVKLL 347
Cdd:cd12073     9 YQGEGDDEISFDPQETITDIEMVDEGWWKG--TCHGH---RGLFPANYVELL 55

Second Src homology 3 domain of Tyrosine kinase substrate (Tks) proteins; Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Vertebrates contain two Tks proteins, Tks4 (Tyr kinase substrate with four SH3 domains) and Tks5 (Tyr kinase substrate with five SH3 domains), which display partially overlapping but non-redundant functions. Both associate with the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. Tks5 interacts with N-WASP and Nck, while Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. Tks proteins contain an N-terminal Phox homology (PX) domain and four or five SH3 domains. This model characterizes the second SH3 domain of Tks proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212949 Cd Length: 54 Bit Score: 40.13 E-value: 1.68e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12016     2 KYITTQAYKAENEDEIGFETGVVVEVIQKNLDGWWKIRYQGKEGWAPATYLK 53

Src Homology 3 domain of fungal BOI-like proteins; This subfamily includes the Saccharomyces cerevisiae proteins BOI1 and BOI2, and similar proteins. They contain an N-terminal SH3 domain, a Sterile alpha motif (SAM), and a Pleckstrin homology (PH) domain at the C-terminus. BOI1 and BOI2 interact with the SH3 domain of Bem1p, a protein involved in bud formation. They promote polarized cell growth and participates in the NoCut signaling pathway, which is involved in the control of cytokinesis. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212819 Cd Length: 55 Bit Score: 40.01 E-value: 1.70e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDD---PDWWQGE--INGVTGLFPSNY 412
Cdd:cd11886     2 LIVIHDFNARSEDELTLKPGDKIELIEDDEefgDGWYLGRnlRTGETGLFPVVF 55

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing (Stac) proteins; Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. This model represents the first C-terminal SH3 domain of Stac1 and Stac3, and the single C-terminal SH3 domain of Stac2. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212767 [Multi-domain] Cd Length: 53 Bit Score: 40.18 E-value: 1.72e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLE-QQENWWFGEVHGGRGWFPKSYV 183
Cdd:cd11833     4 ALYKFKPQENEDLEMRPGDKITLLDdSNEDWWKGKIEDRVGFFPANFV 51

C-terminal (or second) Src homology 3 domain of VAV proteins; VAV proteins function both as cytoplasmic guanine nucleotide exchange factors (GEFs) for Rho GTPases and scaffold proteins and they play important roles in cell signaling by coupling cell surface receptors to various effector functions. They play key roles in processes that require cytoskeletal reorganization including immune synapse formation, phagocytosis, cell spreading, and platelet aggregation, among others. Vertebrates have three VAV proteins (VAV1, VAV2, and VAV3). VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212764 [Multi-domain] Cd Length: 54 Bit Score: 40.31 E-value: 1.78e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGE--WWTGSIGDRSGIFPSNYVK 267
Cdd:cd11830     3 KARYDFCARDMRELSLKEGDVVKIYNKKGQqgWWRGEINGRIGWFPSTYVE 53

First Src homology 3 domain (or SH3A) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN2 is expected to bind many protein partners, similar to ITSN1 which has been shown to bind Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212921 [Multi-domain] Cd Length: 57 Bit Score: 40.24 E-value: 1.80e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQ---QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11988     5 RALYPFEARNHDEMSFNAGDIIQVDEKtvgEPGWLYGSFQGNFGWFPCNYVE 56

C2 domain second repeat present in Synaptotagmin 7; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 7, a member of class 2 synaptotagmins, is located in presynaptic plasma membranes in neurons, dense-core vesicles in endocrine cells, and lysosomes in fibroblasts. It has been shown to play a role in regulation of Ca2+-dependent lysosomal exocytosis in fibroblasts and may also function as a vesicular Ca2+-sensor. It is distinguished from the other synaptotagmins by having over 12 splice forms. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 176050 [Multi-domain] Cd Length: 136 Bit Score: 42.41 E-value: 1.82e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISMGS-----QSYTTRTIQDTLNPKWNfncQFFIKDLYQDVL-----CLTLFD 870
Cdd:cd08405    15 NRITVNIIKARNLKAMDINGTSDPYVKVWLMYkdkrvEKKKTVIKKRTLNPVFN---ESFIFNIPLERLrettlIITVMD 91

                          90
                  ....*....|....*.
gi 1370477838 871 RDQFSPDDFLGRTEIP 886
Cdd:cd08405    92 KDRLSRNDLIGKIYLG 107

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213017 [Multi-domain] Cd Length: 57 Bit Score: 40.17 E-value: 1.83e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQE-----NWWFGEVHGGRGWFPKSYVK 184
Cdd:cd12141     4 AVYTFKARSPNELSVSANQRVRILEFSDltgnkEWWLAEANGQKGYVPSNYIR 56

Src homology 3 domain of RUN and SH3 domain-containing protein 1; RUSC1, also called NESCA (New molecule containing SH3 at the carboxy-terminus), is highly expressed in the brain and is translocated to the nuclear membrane from the cytoplasm upon stimulation with neurotrophin. It plays a role in facilitating neurotrophin-dependent neurite outgrowth. It also interacts with NEMO (or IKKgamma) and may function in NEMO-mediated activation of NF-kB. RUSC proteins are adaptor proteins consisting of RUN, leucine zipper, and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212891 [Multi-domain] Cd Length: 51 Bit Score: 39.82 E-value: 1.94e-04

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 364 VIAMYDYAANnEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNY 412
Cdd:cd11958     2 VRALCDHAGS-ESQLSFRKGEELQVLGTVDEDWIRCRRGDREGLVPVGY 49

Src Homology 3 domain of metazoan osteoclast stimulating factor 1; OSTF1, also named OSF or SH3P2, is a signaling protein containing SH3 and ankyrin-repeat domains. It acts through a Src-related pathway to enhance the formation of osteoclasts and bone resorption. It also acts as a negative regulator of cell motility. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212706 [Multi-domain] Cd Length: 53 Bit Score: 39.98 E-value: 1.94e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSYV 183
Cdd:cd11772     4 ALYDYEAQHPDELSFEEGDLLYISDKSDpNWWKATCGGKTGLIPSNYV 51

C-terminal Src Homology 3 domain of Ct10 Regulator of Kinase adaptor proteins; CRK adaptor proteins consists of SH2 and SH3 domains, which bind tyrosine-phosphorylated peptides and proline-rich motifs, respectively. They function downstream of protein tyrosine kinases in many signaling pathways started by various extracellular signals, including growth and differentiation factors. Cellular CRK (c-CRK) contains a single SH2 domain, followed by N-terminal and C-terminal SH3 domains. It is involved in the regulation of many cellular processes including cell growth, motility, adhesion, and apoptosis. CRK has been implicated in the malignancy of various human cancers. The C-terminal SH3 domain of CRK has not been shown to bind any target protein; it acts as a negative regulator of CRK function by stabilizing a structure that inhibits the access by target proteins to the N-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212693 [Multi-domain] Cd Length: 57 Bit Score: 40.16 E-value: 1.96e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 287 PEIAQVTSAYV--ASGSEQLSLAPGQLILILKKNTSGWWQGELqaRGKkrqKGWFPASHVKL 346
Cdd:cd11759     1 PAYARVIQKRVpnAYDKTALALEVGDLVKVTKINVSGQWEGEL--NGK---VGHFPFTHVEL 57

First Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212853 [Multi-domain] Cd Length: 55 Bit Score: 39.99 E-value: 2.18e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11920     5 AVYDFKAQTSKELSFKKGDTVYILRKiDQNWYEGEHHGRVGIFPISYVE 53

Third N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP binds the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212730 Cd Length: 51 Bit Score: 39.65 E-value: 2.23e-04

                          10        20        30
                  ....*....|....*....|....*....|....*....
gi 1370477838 229 PGDLTFTEGEEILVTQ-KDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11796    13 DEELDLREGDVVTITGiLDKGWFRGELNGRRGIFPEGFV 51

Src Homology 3 domain of beta-Pak Interactive eXchange factor; Beta-PIX, also called Rho guanine nucleotide exchange factor 7 (ARHGEF7) or Cool (Cloned out of Library)-1, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212994 [Multi-domain] Cd Length: 54 Bit Score: 40.05 E-value: 2.25e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 299 SGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:cd12061    11 TNEDELSFSKGDVIHVTRVEEGGWWEGTHNGR-----TGWFPSNYVR 52

C2 domain second repeat in Copine; There are 2 copies of the C2 domain present in copine, a protein involved in membrane trafficking, protein-protein interactions, and perhaps even cell division and growth. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 176012 [Multi-domain] Cd Length: 110 Bit Score: 41.40 E-value: 2.27e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 808 IEATELKACKPNGKSNPYCEISMGSQS------YTTRTIQDTLNPKWN-FNCQFFikDL----YQDVLCLTLFDRDQFSP 876
Cdd:cd04047     7 FSGKKLDKKDFFGKSDPFLEISRQSEDgtwvlvYRTEVIKNTLNPVWKpFTIPLQ--KLcngdYDRPIKIEVYDYDSSGK 84

                          90
                  ....*....|....*...
gi 1370477838 877 DDFLGRTEIPVAKIRTEQ 894
Cdd:cd04047    85 HDLIGEFETTLDELLKSS 102

C2 domain present in Soybean genes Regulated by Cold 2 (SRC2)-like proteins; SRC2 production is a response to pathogen infiltration. The initial response of increased Ca2+ concentrations are coupled to downstream signal transduction pathways via calcium binding proteins. SRC2 contains a single C2 domain which localizes to the plasma membrane and is involved in Ca2+ dependent protein binding. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176016 [Multi-domain] Cd Length: 125 Bit Score: 41.83 E-value: 2.62e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 807 VIEATELKACKPNGKSNPYCEISM-GSQSYTTRTiqDTL---NPKWNFNCQFFIKD--LYQDVLCLT--LFDRDQFSPDD 878
Cdd:cd04051     6 IISAEDLKNVNLFGKMKVYAVVWIdPSHKQSTPV--DRDggtNPTWNETLRFPLDErlLQQGRLALTieVYCERPSLGDK 83

                          90
                  ....*....|
gi 1370477838 879 FLGRTEIPVA 888
Cdd:cd04051    84 LIGEVRVPLK 93

Src homology 3 domain of Brk (Breast tumor kinase) Protein Tyrosine Kinase (PTK), also called PTK6; Brk is a cytoplasmic (or non-receptor) PTK with limited homology to Src kinases. It has been found to be overexpressed in a majority of breast tumors. It plays roles in normal cell differentiation, proliferation, survival, migration, and cell cycle progression. Brk substrates include RNA-binding proteins (SLM-1/2, Sam68), transcription factors (STAT3/5), and signaling molecules (Akt, paxillin, IRS-4). Src kinases in general contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr; they are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Brk lacks the N-terminal myristoylation site. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212781 [Multi-domain] Cd Length: 58 Bit Score: 39.85 E-value: 2.65e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDpDWWQ----GEINGVT--GLFPSNYV 413
Cdd:cd11847     3 KALWDFKARGDEELSFQAGDQFRIAERSG-DWWTalklDRAGGVVaqGFVPNNYL 56

Src Homology 3 domain of Mixed Lineage Kinases; MLKs are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Mammals have four MLKs (MLK1-4), mostly conserved in vertebrates, which contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212809 [Multi-domain] Cd Length: 58 Bit Score: 39.80 E-value: 2.73e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTS-----GWWQGELQARgkkrqKGWFPASHV 344
Cdd:cd11876     8 YDARGEDELTLRRGQPVEVLSKDAAvsgdeGWWTGKIGDK-----VGIFPSNYV 56

Src Homology 3 domain of alpha-Pak Interactive eXchange factor; Alpha-PIX, also called Rho guanine nucleotide exchange factor 6 (ARHGEF6) or Cool (Cloned out of Library)-2, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and is localized in dendritic spines where it regulates spine morphogenesis. It controls dendritic length and spine density in the hippocampus. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212993 Cd Length: 58 Bit Score: 39.60 E-value: 2.76e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1370477838 302 EQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:cd12060    16 DELSVCKGDIIYVTRVEEGGWWEGTLNGK-----TGWFPSNYVR 54

Second Src homology 3 domain of Tyrosine kinase substrate with five SH3 domains; Tks5, also called SH3 and PX domain-containing protein 2A (SH3PXD2A) or Five SH (FISH), is a scaffolding protein and Src substrate that is localized in podosomes, which are electron-dense structures found in Src-transformed fibroblasts, osteoclasts, macrophages, and some invasive cancer cells. It binds and regulates some members of the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. It is required for podosome formation, degradation of the extracellular matrix, and cancer cell invasion. Tks5 contains an N-terminal Phox homology (PX) domain and five SH3 domains. This model characterizes the second SH3 domain of Tks5. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213010 Cd Length: 54 Bit Score: 39.63 E-value: 2.81e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 295 AYVASGSEQLSLAPGQLILILKKNTSGWWQgeLQARGKkrqKGWFPASHVK 345
Cdd:cd12077     8 PYTSQGKDEIGFEKGVTVEVIQKNLEGWWY--IRYLGK---EGWAPASYLK 53

C2 domain first repeat present in Synaptotagmin-like proteins; All Slp members basically share an N-terminal Slp homology domain (SHD) and C-terminal tandem C2 domains (named the C2A domain and the C2B domain) with the SHD and C2 domains being separated by a linker sequence of various length. Slp1/JFC1 and Slp2/exophilin 4 promote granule docking to the plasma membrane. Additionally, their C2A domains are both Ca2+ independent, unlike the case in Slp3 and Slp4/granuphilin in which their C2A domains are Ca2+ dependent. It is thought that SHD (except for the Slp4-SHD) functions as a specific Rab27A/B-binding domain. In addition to Slps, rabphilin, Noc2, and Munc13-4 also function as Rab27-binding proteins. It has been demonstrated that Slp3 and Slp4/granuphilin promote dense-core vesicle exocytosis. Slp5 mRNA has been shown to be restricted to human placenta and liver suggesting a role in Rab27A-dependent membrane trafficking in specific tissues. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 176056 [Multi-domain] Cd Length: 123 Bit Score: 41.47 E-value: 2.86e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 794 SQKTSGigrLMVHVIEATELKACKP-NGKSNPYCEI------SMGSQSyTTRTIQDTLNPKWNFNCQFFIK--DLYQDVL 864
Cdd:cd08521    10 NYKTGS---LEVHIKECRNLAYADEkKKRSNPYVKVyllpdkSKQSKR-KTSVKKNTTNPVFNETLKYHISksQLETRTL 85

                          90       100
                  ....*....|....*....|....
gi 1370477838 865 CLTLFDRDQFSPDDFLGRTEIPVA 888
Cdd:cd08521    86 QLSVWHHDRFGRNTFLGEVEIPLD 109

Src homology 3 domain of the Rho guanine nucleotide exchange factor ARHGEF9; ARHGEF9, also called PEM2 or collybistin, selectively activates Cdc42 by exchanging bound GDP for free GTP. It is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. Mutations in the ARHGEF9 gene cause X-linked mental retardation with associated features like seizures, hyper-anxiety, aggressive behavior, and sensory hyperarousal. ARHGEF9 contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212908 Cd Length: 62 Bit Score: 39.69 E-value: 2.87e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 133 LKAQALCSWTAKKDNHLNFSKHDIITVLE-QQENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11975     5 VSAEAVWDHVTMANRELAFKAGDVIKVLDaSNKDWWWGQIDDEEGWFPASFVRL 58

Src Homology 3 domain of fungal peroxisomal membrane protein Pex13p; Pex13p, located in the peroxisomal membrane, contains two transmembrane regions and a C-terminal SH3 domain. It binds to the peroxisomal targeting type I (PTS1) receptor Pex5p and the docking factor Pex14p through its SH3 domain. It is essential for both PTS1 and PTS2 protein import pathways into the peroxisomal matrix. Pex13p binds Pex14p, which contains a PxxP motif, in a classical fashion to the proline-rich ligand binding site of its SH3 domain. It binds the WxxxF/Y motif of Pex5p in a novel site that does not compete with Pex14p binding. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212705 [Multi-domain] Cd Length: 60 Bit Score: 39.57 E-value: 2.90e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 302 EQLSLAPGQLILILKK-----NTSGWWQGelqaRGKKRQKGWFPASHV 344
Cdd:cd11771    15 MELSLKKGDIVAVLSKtdplgRDSEWWKG----RTRDGRIGWFPSNYV 58

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding proteins; CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes including migration, chemotaxis, apoptosis, differentiation, and progenitor cell function. They mediate the signaling of integrins at focal adhesions where they localize, and thus, regulate cell invasion and survival. Over-expression of these proteins is implicated in poor prognosis, increased metastasis, and resistance to chemotherapeutics in many cancers such as breast, lung, melanoma, and glioblastoma. CAS proteins have also been linked to the pathogenesis of inflammatory disorders, Alzheimer's, Parkinson's, and developmental defects. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. Vertebrates contain four CAS proteins: BCAR1 (or p130Cas), NEDD9 (or HEF1), EFS (or SIN), and CASS4 (or HEPL). The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212778 Cd Length: 56 Bit Score: 39.64 E-value: 2.92e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQ----ENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd11844     2 ARALYDNVAESPDELAFRRGDILTVLEQNtaglEGWWLCSLRGRQGIAPGNRLKL 56

Src homology 3 domain of Endophilin-B; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain two endophilin-B isoforms. Endophilin-B proteins are cytoplasmic proteins expressed mainly in the heart, placenta, and skeletal muscle. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212736 [Multi-domain] Cd Length: 52 Bit Score: 39.58 E-value: 2.97e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLE---QQENWWFGEVHGGRGWFPKSY 182
Cdd:cd11802     1 KARVLYDYDAEDSTELSLLADEVITVYElpgMDEDYMMGERGSQRGKVPVAY 52

Second Src homology 3 domain of Tyrosine kinase substrate with five SH3 domains; Tks5, also called SH3 and PX domain-containing protein 2A (SH3PXD2A) or Five SH (FISH), is a scaffolding protein and Src substrate that is localized in podosomes, which are electron-dense structures found in Src-transformed fibroblasts, osteoclasts, macrophages, and some invasive cancer cells. It binds and regulates some members of the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. It is required for podosome formation, degradation of the extracellular matrix, and cancer cell invasion. Tks5 contains an N-terminal Phox homology (PX) domain and five SH3 domains. This model characterizes the second SH3 domain of Tks5. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213010 Cd Length: 54 Bit Score: 39.63 E-value: 3.01e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12077     4 VTVQPYTSQGKDEIGFEKGVTVEVIQKNLEGWWYIRYLGKEGWAPASYLK 53

Src Homology 3 domain of Sorting nexin 18; SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. It binds FIP5 and is required for apical lumen formation. It may also play a role in axonal elongation. SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX18 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212830 [Multi-domain] Cd Length: 55 Bit Score: 39.59 E-value: 3.02e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWW---TGSIGDRsGIFPSNYVK 267
Cdd:cd11897     4 ALYDFRSENPGEISLREHEVLsLCSEQDIEGWlegVNSRGDR-GLFPASYVE 54

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member, Neural precursor cell Expressed, Developmentally Down-regulated 9; NEDD9 is also called human enhancer of filamentation 1 (HEF1) or CAS-L (Crk-associated substrate in lymphocyte). It was first described as a gene predominantly expressed in early embryonic brain, and was also isolated from a screen of human proteins that regulate filamentous budding in yeast, and as a tyrosine phosphorylated protein in lymphocytes. It promotes metastasis in different solid tumors. NEDD9 localizes in focal adhesions and associates with FAK and Abl kinase. It also interacts with SMAD3 and the proteasomal machinery which allows its rapid turnover; these interactions are not shared by other CAS proteins. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212935 Cd Length: 57 Bit Score: 39.58 E-value: 3.04e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDD---PDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd12002     4 ALYDNVPECAEELAFRKGDILTVIEQNTgglEGWWLCSLHGRQGIAPGNRLKL 56

Second Src Homology 3 domain (SH3B) of CD2-associated protein and similar proteins; This subfamily is composed of the second SH3 domain (SH3B) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3B of both proteins have been shown to bind to Cbl. In the case of CD2AP, its SH3B binds to Cbl at a site distinct from the c-Cbl/SH3A binding site. The CIN85 SH3B also binds ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212807 [Multi-domain] Cd Length: 53 Bit Score: 39.24 E-value: 3.04e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWqgelqaRGKKRQK-GWFPASHVKL 346
Cdd:cd11874     2 CKVLFSYTPQNEDELELKVGDTIEVLGEVEEGWW------EGKLNGKvGVFPSNFVKE 53

Src homology 3 domain of SH3 and multiple ankyrin repeat domains protein 3; Shank3, also called ProSAP2 (Proline-rich synapse-associated protein 2), is widely expressed. It plays a role in the formation of dendritic spines and synapses. Haploinsufficiency of the Shank3 gene causes the 22q13 deletion/Phelan-McDermid syndrome, and variants of Shank3 have been implicated in autism spectrum disorder, schizophrenia, and intellectual disability. Shank proteins carry scaffolding functions through multiple sites of protein-protein interaction in its domain architecture, including ankyrin (ANK) repeats, a long proline rich region, as well as SH3, PDZ, and SAM domains. The SH3 domain of Shank binds GRIP, a scaffold protein that binds AMPA receptors and Eph receptors/ligands. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212917 Cd Length: 52 Bit Score: 39.16 E-value: 3.24e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQ-KDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11984     3 FIAVKAYSPQGEGEIQLNRGERVKVLSiGEGGFWEGTVKGRTGWFPADCV 52

Src Homology 3 domain of Class A and B Dedicator of Cytokinesis proteins; DOCK proteins are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. They are divided into four classes (A-D) based on sequence similarity and domain architecture: class A includes Dock1, 2 and 5; class B includes Dock3 and 4; class C includes Dock6, 7, and 8; and class D includes Dock9, 10 and 11. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. This subfamily includes only Class A and B DOCKs, which also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus. Class A/B DOCKs are mostly specific GEFs for Rac, except Dock4 which activates the Ras family GTPase Rap1, probably indirectly through interaction with Rap regulatory proteins. The SH3 domain of class A/B DOCKs have been shown to bind Elmo, a scaffold protein that promotes GEF activity of DOCKs by releasing DHR-2 autoinhibition by the intramolecular SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212805 [Multi-domain] Cd Length: 56 Bit Score: 39.49 E-value: 3.26e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNtSGWWQGELQarGKKRQKGWFPASHVKL 346
Cdd:cd11872     8 FQGDGEHQLSLQVGDTVQILEEC-EGWYRGFSL--RNKSLKGIFPKSYVHI 55

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing proteins; ASAPs are Arf GTPase activating proteins (GAPs) and they function in regulating cell growth, migration, and invasion. They contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. Vertebrates contain at least three members, ASAP1, ASAP2, and ASAP3, but some ASAP3 proteins do not seem to harbor a C-terminal SH3 domain. ASAP1 and ASAP2 show GTPase activating protein (GAP) activity towards Arf1 and Arf5. They do not show GAP activity towards Arf6, but are able to mediate Arf6 signaling by binding stably to GTP-Arf6. ASAP3 is an Arf6-specific GAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212755 [Multi-domain] Cd Length: 53 Bit Score: 39.22 E-value: 3.27e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1370477838 297 VASGSEQLSLAPGQLILILKKNTSGWWQGELQarGKKRQKGWFPAS 342
Cdd:cd11821     9 QADNDDELTFSEGEIIVVTGEEDDEWWEGHIE--GDPSRRGVFPVS 52

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member 4; CASS4, also called HEPL (HEF1-EFS-p130Cas-like), localizes to focal adhesions and plays a role in regulating FAK activity, focal adhesion integrity, and cell spreading. It is most abundant in blood cells and lung tissue, and is also found in high levels in leukemia and ovarian cell lines. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212933 Cd Length: 57 Bit Score: 39.48 E-value: 3.34e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 133 LKAQALCSWTAKKDNHLNFSKHDIITVLEQQ----ENWWFGEVHGGRGWFP 179
Cdd:cd12000     1 LLARALYDNKADCSDELAFRRGDILTVLEQNvpgsEGWWKCLLHGRQGLAP 51

Second Src Homology 3 domain (SH3B) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CIN85. SH3B has been shown to bind Cbl proline-rich peptides and ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212988 [Multi-domain] Cd Length: 53 Bit Score: 39.21 E-value: 3.35e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVL-EQQENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd12055     1 RCQVAFSYLPQNEDELELKVGDIIEVVgEVEEGWWEGVLNGKTGMFPSNFIK 52

Src Homology 3 domain of Insulin Receptor tyrosine kinase Substrate p53; IRSp53 is also known as BAIAP2 (Brain-specific Angiogenesis Inhibitor 1-Associated Protein 2). It is a scaffolding protein that takes part in many signaling pathways including Cdc42-induced filopodia formation, Rac-mediated lamellipodia extension, and spine morphogenesis. IRSp53 exists as multiple splicing variants that differ mainly at the C-termini. One variant (T-form) is expressed exclusively in human breast cancer cells. The gene encoding IRSp53 is a putative susceptibility gene for Gilles de la Tourette syndrome. IRSp53 can also mediate the recruitment of effector proteins Tir and EspFu, which regulate host cell actin reorganization, to bacterial attachment sites. It contains an N-terminal IMD, a CRIB (Cdc42 and Rac interactive binding motif), an SH3 domain, and a WASP homology 2 (WH2) actin-binding motif at the C-terminus. The SH3 domain of IRSp53 has been shown to bind the proline-rich C-terminus of EspFu. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212848 Cd Length: 59 Bit Score: 39.61 E-value: 3.36e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1370477838 134 KAQALCSWTAKkDNH--LNFSKHDIITVL--EQQENWWFGEVHGG--RGWFPKSYVKII 186
Cdd:cd11915     2 RVQAIFSHAAG-DNStlLSFKEGDYITLLvpEARDGWHYGECEKTkmRGWFPFSYTRVL 59

Src Homology 3 domain of Apoptosis Stimulating of p53 protein 1; ASPP1, like ASPP2, activates the apoptotic function of the p53 family of tumor suppressors (p53, p63, and p73). In addition, it functions in the cytoplasm to regulate the nuclear localization of the transcriptional cofactors YAP and TAZ by inihibiting their phosphorylation; YAP and TAZ are important regulators of cell expansion, differentiation, migration, and invasion. ASPP1 is downregulated in breast tumors expressing wild-type p53. It contains a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain at its C-terminal half. The SH3 domain and the ANK repeats of ASPP1 contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212887 [Multi-domain] Cd Length: 57 Bit Score: 39.62 E-value: 3.41e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEI-LVTQKDG---EWWTGSIGDRSGIFPSN 264
Cdd:cd11954     5 ALWDYEAQNADELSFQEGDAItILRRKDDsetEWWWARLNDKEGYVPKN 53

C-terminal (or second) Src homology 3 domain of VAV3 protein; VAV3 is ubiquitously expressed and functions as a phosphorylation-dependent guanine nucleotide exchange factor (GEF) for RhoA, RhoG, and Rac1. It has been implicated to function in the hematopoietic, bone, cerebellar, and cardiovascular systems. VAV3 is essential in axon guidance in neurons that control blood pressure and respiration. It is overexpressed in prostate cancer cells and it plays a role in regulating androgen receptor transcriptional activity. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212911 [Multi-domain] Cd Length: 56 Bit Score: 39.24 E-value: 3.48e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQ--ENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11978     3 AIARYDFCARDMRELSLLKGDVVKIYTKMstNGWWRGEVNGRVGWFPSTYVE 54

Src homology 3 domain of the Rho guanine nucleotide exchange factor, ephexin-1 (also called NGEF or ARHGEF27); Ephexin-1, also called NGEF (neuronal GEF) or ARHGEF27, activates RhoA, Tac1, and Cdc42 by exchanging bound GDP for free GTP. It is expressed mainly in the brain in a region associated with movement control. It regulates the stability of postsynaptic acetylcholine receptor (AChR) clusters and thus, plays a critical role in the maturation and neurotransmission of neuromuscular junctions. Ephexin-1 directly interacts with the ephrin receptor EphA4 and their coexpression enhances the ability of ephexin-1 to activate RhoA. It is required for normal axon growth and EphA-induced growth cone collapse. Ephexin-1 contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212872 [Multi-domain] Cd Length: 55 Bit Score: 39.54 E-value: 3.48e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 291 QVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGElqaRGKKRQKGWFPASHVK 345
Cdd:cd11939     3 QCVHPYVSQEPDELSLELADVLNILDKTDDGWIFGE---RLHDQERGWFPSSVVE 54

Src Homology 3 domain of Calcium/calmodulin-dependent Serine protein Kinase; CASK is a scaffolding protein that is highly expressed in the mammalian nervous system and plays roles in synaptic protein targeting, neural development, and gene expression regulation. CASK interacts with many different binding partners including parkin, neurexin, syndecans, calcium channel proteins, caskin, among others, to perform specific functions in different subcellular locations. Disruption of the CASK gene in mice results in neonatal lethality while mutations in the human gene have been associated with X-linked mental retardation. Drosophila CASK is associated with both pre- and postsynaptic membranes and is crucial in synaptic transmission and vesicle cycling. CASK contains an N-terminal calmodulin-dependent kinase (CaMK)-like domain, two L27 domains, followed by the core of three domains characteristic of MAGUK (membrane-associated guanylate kinase) proteins: PDZ, SH3, and guanylate kinase (GuK). In addition, it also contains the Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213014 Cd Length: 62 Bit Score: 39.50 E-value: 3.52e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1370477838 364 VIAMYDYAANnEDEL--------SFSKGQLINVMNKDDPDWWQGE----INGVTGLFPS 410
Cdd:cd12081     2 VRAQFEYDPL-KDDLipckqagiRFRVGDILQIISKDDHNWWQAKlensKNGTAGLIPS 59

Second Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the second SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212721 [Multi-domain] Cd Length: 53 Bit Score: 39.24 E-value: 3.52e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 219 IALYPYssvEPGD------LTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNY 265
Cdd:cd11787     3 KALYDF---EMKDedekdcLTFKKGDVITVIRRvDENWAEGRLGDKIGIFPISF 53

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member, Embryonal Fyn-associated Substrate; EFS is also called HEFS, CASS3 (Cas scaffolding protein family member 3) or SIN (Src-interacting protein). It was identified based on interactions with the Src kinases, Fyn and Yes. It plays a role in thymocyte development and acts as a negative regulator of T cell proliferation. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212936 Cd Length: 62 Bit Score: 39.49 E-value: 3.55e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE----WWTGSIGDRSGIFPSNYVK 267
Cdd:cd12003     5 ALYDNAAESPEELSFRRGDVLMVLKREHGslpgWWLCSLHGQQGIAPANRLR 56

Src homology 3 domain of APC-Stimulated guanine nucleotide Exchange Factor 2; ASEF2, also called Spermatogenesis-associated protein 13 (SPATA13), is a GEF that localizes with actin at the leading edge of cells and is important in cell migration and adhesion dynamics. GEFs activate small GTPases by exchanging bound GDP for free GTP. ASEF2 can activate both Rac 1 and Cdc42, but only Rac1 activation is necessary for increased cell migration and adhesion turnover. Together with APC (adenomatous polyposis coli) and Neurabin2, a scaffold protein that binds F-actin, it is involved in regulating HGF-induced cell migration. ASEF2 contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212907 Cd Length: 54 Bit Score: 39.28 E-value: 3.55e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQ-KDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11974     5 ALWDHVTMDDQELAFKAGDVIRVLEaSNKDWWWGRNEDREAWFPASFVR 53

Src Homology 3 domain of Cdc42-Interacting Protein 4; This subfamily is composed of Cdc42-Interacting Protein 4 (CIP4), Formin Binding Protein 17 (FBP17), FormiN Binding Protein 1-Like (FNBP1L), and similar proteins. CIP4 and FNBP1L are Cdc42 effectors that bind Wiskott-Aldrich syndrome protein (WASP) and function in endocytosis. CIP4 and FBP17 bind to the Fas ligand and may be implicated in the inflammatory response. CIP4 may also play a role in phagocytosis. It functions downstream of Cdc42 in PDGF-dependent actin reorganization and cell migration, and also regulates the activity of PDGFRbeta. It uses Src as a substrate in regulating the invasiveness of breast tumor cells. CIP4 may also play a role in the pathogenesis of Huntington's disease. Members of this subfamily typically contain an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain, a central Cdc42-binding HR1 domain, and a C-terminal SH3 domain. The SH3 domain of CIP4 associates with Gapex-5, a Rab31 GEF. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212844 [Multi-domain] Cd Length: 55 Bit Score: 39.17 E-value: 3.57e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQG--EINGVTGLFPSNYVKM 415
Cdd:cd11911     1 TCTALYDFDGTSEGTLSMEEGEILLVLEEDGGDGWTRvrKNNGDEGYVPTSYIEV 55

Src Homology 3 domain of SH3 domain and tetratricopeptide repeat-containing (SH3TC) proteins and similar domains; This subfamily is composed of vertebrate SH3TC proteins and hypothetical fungal proteins containing BAR and SH3 domains. Mammals contain two SH3TC proteins, SH3TC1 and SH3TC2. The function of SH3TC1 is unknown. SH3TC2 is localized in Schwann cells in the peripheral nervous system, where it interacts with Rab11 and plays a role in peripheral nerve myelination. Mutations in SH3TC2 are associated with Charcot-Marie-Tooth disease type 4C, a severe hereditary peripheral neuropathy with symptoms that include progressive scoliosis, delayed age of walking, muscular atrophy, distal weakness, and reduced nerve conduction velocity. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212818 Cd Length: 55 Bit Score: 39.22 E-value: 3.61e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVT---QKDGEWWTGSIGD--RSGIFPSNYV 266
Cdd:cd11885     4 AKMDFEGVEPGELSFRQGDSIEIIgdlIPGLQWFVGRSKSsgRVGFVPTNHF 55

Src Homology 3 domain of Myosin XVb; Myosin XVb, also called KIAA1783, was named based on its similarity with myosin XVa. It is a transcribed and unprocessed pseudogene whose predicted amino acid sequence contains mutated or deleted amino acid residues that are normally conserved and important for myosin function. The related myosin XVa is important for normal growth of mechanosensory stereocilia of inner ear hair cells. Myosin XVa contains a unique N-terminal extension followed by a motor domain, light chain-binding IQ motifs, and a tail consisting of a pair of MyTH4-FERM tandems separated by a SH3 domain, and a PDZ domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 213001 Cd Length: 55 Bit Score: 39.47 E-value: 3.65e-04

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINV--MNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12068     2 VVALRSYITDDKSLLSFHRGDLIKLlpMAGLEPGWQFGSTGGRSGLFPADIVQ 54

First Src homology 3 domain of Tyrosine kinase substrate (Tks) proteins; Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Vertebrates contain two Tks proteins, Tks4 (Tyr kinase substrate with four SH3 domains) and Tks5 (Tyr kinase substrate with five SH3 domains), which display partially overlapping but non-redundant functions. Both associate with the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. Tks5 interacts with N-WASP and Nck, while Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. Tks proteins contain an N-terminal Phox homology (PX) domain and four or five SH3 domains. This model characterizes the first SH3 domain of Tks proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212948 Cd Length: 53 Bit Score: 39.33 E-value: 3.70e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 129 VVENLKAQalcswtakKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSY 182
Cdd:cd12015     4 VVADYKKQ--------QPNEISLRAGDVVDVIEKNENgWWFVSLEDEQGWVPATY 50

Second or C-terminal Src homology 3 domain of the p47phox subunit of NADPH oxidase, also called Neutrophil Cytosolic Factor 1; p47phox, or NCF1, is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox), which plays a key role in the ability of phagocytes to defend against bacterial infections. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p47phox is required for activation of NADH oxidase and plays a role in translocation. It contains an N-terminal Phox homology (PX) domain, tandem SH3 domains (N-SH3 and C-SH3), a polybasic/autoinhibitory region, and a C-terminal proline-rich region (PRR). This model characterizes the second SH3 domain (or C-SH3) of p47phox. In its inactive state, the tandem SH3 domains interact intramolecularly with the autoinhibitory region; upon activation, the tandem SH3 domains are exposed through a conformational change, resulting in their binding to the PRR of p22phox and the activation of NADPH oxidase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212955 [Multi-domain] Cd Length: 53 Bit Score: 39.05 E-value: 3.70e-04

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYVK 414
Cdd:cd12022     3 ITIKAYTAVEEDELTLLEGEAIEVIHKLLDGWWVVRKGEVTGYFPSMYLQ 52

Second Src homology 3 domain of Tyrosine kinase substrate (Tks) proteins; Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Vertebrates contain two Tks proteins, Tks4 (Tyr kinase substrate with four SH3 domains) and Tks5 (Tyr kinase substrate with five SH3 domains), which display partially overlapping but non-redundant functions. Both associate with the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. Tks5 interacts with N-WASP and Nck, while Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. Tks proteins contain an N-terminal Phox homology (PX) domain and four or five SH3 domains. This model characterizes the second SH3 domain of Tks proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212949 Cd Length: 54 Bit Score: 39.36 E-value: 3.73e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 292 VTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:cd12016     5 TTQAYKAENEDEIGFETGVVVEVIQKNLDGWWKIRYQGK-----EGWAPATYLK 53

Src homology 3 domain of RUN and SH3 domain-containing protein 2; RUSC2, also called Iporin or Interacting protein of Rab1, is expressed ubiquitously with highest amounts in the brain and testis. It interacts with the small GTPase Rab1 and the Golgi matrix protein GM130, and may function in linking GTPases to certain intracellular signaling pathways. RUSC proteins are adaptor proteins consisting of RUN, leucine zipper, and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212890 Cd Length: 52 Bit Score: 39.13 E-value: 3.74e-04

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11957     1 EVKALCHHIATEPGQLSFNKGDILQVLSRADGDWLRCSLGPDSGLVPIAYV 51

Src Homology 3 (SH3) domain of Inhibitor of ASPP protein (iASPP); iASPP, also called RelA-associated inhibitor (RAI), is an oncoprotein that inhibits the apoptotic transactivation potential of p53. It is upregulated in human breast cancers expressing wild-type p53, in acute leukemias regardless of the p53 mutation status, as well as in ovarian cancer where it is associated with poor patient outcome and chemoresistance. iASPP is also a binding partner and negative regulator of p65RelA, which promotes cell proliferation and inhibits apoptosis; p65RelA has the opposite effect on cell growth compared to the p53 family. It contains a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain at its C-terminal half. The SH3 domain and the ANK repeats of iASPP contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212885 [Multi-domain] Cd Length: 56 Bit Score: 39.14 E-value: 3.86e-04

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLE---QQENWWFGEVHGGRGWFPKSY 182
Cdd:cd11952     5 ALWDYSAEFPDELSFKEGDMVTVLRkdgEGTDWWWASLCGREGYVPRNY 53

Src homology 3 domain of Type I fungal Myosins; Type I myosins (myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Saccharomyces cerevisiae has two myosins-I, Myo3 and Myo5, which are involved in endocytosis and the polarization of the actin cytoskeleton. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212792 [Multi-domain] Cd Length: 55 Bit Score: 39.29 E-value: 3.87e-04

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRS--GIFPSNYVKP 268
Cdd:cd11858     2 YKALYDFAGSVANELSLKKDDIVYIVQKeDNGWWLAKKLDESkeGWVPAAYLEE 55

First Src homology 3 domain (or SH3A) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212920 [Multi-domain] Cd Length: 55 Bit Score: 39.21 E-value: 4.08e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 218 YIALYPYSS-------VEPGDLTFTEGEEilvTQKDGeWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11987     2 YRALYPFEArshdeitIQPGDIVMVDESQ---TGEPG-WLGGELKGKTGWFPANYAE 54

Second Src homology 3 domain of Tyrosine kinase substrate with five SH3 domains; Tks5, also called SH3 and PX domain-containing protein 2A (SH3PXD2A) or Five SH (FISH), is a scaffolding protein and Src substrate that is localized in podosomes, which are electron-dense structures found in Src-transformed fibroblasts, osteoclasts, macrophages, and some invasive cancer cells. It binds and regulates some members of the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. It is required for podosome formation, degradation of the extracellular matrix, and cancer cell invasion. Tks5 contains an N-terminal Phox homology (PX) domain and five SH3 domains. This model characterizes the second SH3 domain of Tks5. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213010 Cd Length: 54 Bit Score: 39.24 E-value: 4.12e-04

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                  ....*....|....*....|....*....|....*....|....*
gi 1370477838 141 WTAKKDNHLNFSKHDIITVLEQQ-ENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd12077     9 YTSQGKDEIGFEKGVTVEVIQKNlEGWWYIRYLGKEGWAPASYLK 53

C2 domain first repeat in Ferlin; Ferlins are involved in vesicle fusion events. Ferlins and other proteins, such as Synaptotagmins, are implicated in facilitating the fusion process when cell membranes fuse together. There are six known human Ferlins: Dysferlin (Fer1L1), Otoferlin (Fer1L2), Myoferlin (Fer1L3), Fer1L4, Fer1L5, and Fer1L6. Defects in these genes can lead to a wide range of diseases including muscular dystrophy (dysferlin), deafness (otoferlin), and infertility (fer-1, fertilization factor-1). Structurally they have 6 tandem C2 domains, designated as (C2A-C2F) and a single C-terminal transmembrane domain, though there is a new study that disputes this and claims that there are actually 7 tandem C2 domains with another C2 domain inserted between C2D and C2E. In a subset of them (Dysferlin, Myoferlin, and Fer1) there is an additional conserved domain called DysF. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-II topology.

Pssm-ID: 176019 [Multi-domain] Cd Length: 127 Bit Score: 41.09 E-value: 4.17e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 819 NGKSNPYCEISMGSQSYTTRTIQDTLNPKWNfncQFFIKDLY-----QDVLCLTLFDRDQFSPDDFLGRTEIP 886
Cdd:cd08373    12 KGKGDRIAKVTFRGVKKKTRVLENELNPVWN---ETFEWPLAgspdpDESLEIVVKDYEKVGRNRLIGSATVS 81

Src homology 3 domain of APC-Stimulated guanine nucleotide Exchange Factor 2; ASEF2, also called Spermatogenesis-associated protein 13 (SPATA13), is a GEF that localizes with actin at the leading edge of cells and is important in cell migration and adhesion dynamics. GEFs activate small GTPases by exchanging bound GDP for free GTP. ASEF2 can activate both Rac 1 and Cdc42, but only Rac1 activation is necessary for increased cell migration and adhesion turnover. Together with APC (adenomatous polyposis coli) and Neurabin2, a scaffold protein that binds F-actin, it is involved in regulating HGF-induced cell migration. ASEF2 contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212907 Cd Length: 54 Bit Score: 39.28 E-value: 4.20e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGelqaRGKKRQkGWFPASHVKL 346
Cdd:cd11974     9 HVTMDDQELAFKAGDVIRVLEASNKDWWWG----RNEDRE-AWFPASFVRL 54

C2 domain second repeat present in Synaptotagmin 1; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 1, a member of the class 1 synaptotagmins, is located in the brain and endocranium and localized to the synaptic vesicles and secretory granules. It functions as a Ca2+ sensor for fast exocytosis. It, like synaptotagmin-2, has an N-glycosylated N-terminus. Synaptotagmin 4, a member of class 4 synaptotagmins, is located in the brain. It functions are unknown. It, like synaptotagmin-11, has an Asp to Ser substitution in its C2A domain. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 176047 [Multi-domain] Cd Length: 136 Bit Score: 41.23 E-value: 4.29e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISMG------SQSYTTRTiQDTLNPKWNFNCQFFIK-DLYQDV-LCLTLFDRD 872
Cdd:cd08402    15 GKLTVVILEAKNLKKMDVGGLSDPYVKIHLMqngkrlKKKKTTIK-KRTLNPYYNESFSFEVPfEQIQKVhLIVTVLDYD 93

                          90
                  ....*....|
gi 1370477838 873 QFSPDDFLGR 882
Cdd:cd08402    94 RIGKNDPIGK 103

Src homology 3 domain of RUN and SH3 domain-containing proteins 1 and 2; RUSC1 and RUSC2, that were originally characterized in silico. They are adaptor proteins consisting of RUN, leucine zipper, and SH3 domains. RUSC1, also called NESCA (New molecule containing SH3 at the carboxy-terminus), is highly expressed in the brain and is translocated to the nuclear membrane from the cytoplasm upon stimulation with neurotrophin. It plays a role in facilitating neurotrophin-dependent neurite outgrowth. It also interacts with NEMO (or IKKgamma) and may function in NEMO-mediated activation of NF-kB. RUSC2, also called Iporin, is expressed ubiquitously with highest amounts in the brain and testis. It interacts with the small GTPase Rab1 and the Golgi matrix protein GM130, and may function in linking GTPases to certain intracellular signaling pathways. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212744 Cd Length: 50 Bit Score: 38.96 E-value: 4.36e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNY 412
Cdd:cd11810     2 VRALCHHVATDSGQLSFRKGDILRVIARVDDDWLLCTRGSTKGLVPLSY 50

Src homology 3 domain of SH3 and multiple ankyrin repeat domains (Shank) proteins; Shank proteins carry scaffolding functions through multiple sites of protein-protein interaction in its domain architecture, including ankyrin (ANK) repeats, a long proline rich region, as well as SH3, PDZ, and SAM domains. They bind a variety of membrane and cytosolic proteins, and exist in alternatively spliced isoforms. They are highly enriched in postsynaptic density (PSD) where they interact with the cytoskeleton and with postsynaptic membrane receptors including NMDA and glutamate receptors. They are crucial in the construction and organization of the PSD and dendritic spines of excitatory synapses. There are three members of this family (Shank1, Shank2, Shank3) which show distinct and cell-type specific patterns of expression. Shank1 is brain-specific; Shank2 is found in neurons, glia, endocrine cells, liver, and kidney; Shank3 is widely expressed. The SH3 domain of Shank binds GRIP, a scaffold protein that binds AMPA receptors and Eph receptors/ligands. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212766 Cd Length: 50 Bit Score: 38.57 E-value: 4.88e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQ-KDGEWWTGSIGDRSGIFPS 263
Cdd:cd11832     2 FIAVKSYSPQEEGEISLHKGDRVKVLSiGEGGFWEGSVRGRTGWFPS 48

Second Src Homology 3 domain of Nck adaptor proteins; Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212700 [Multi-domain] Cd Length: 53 Bit Score: 38.79 E-value: 4.96e-04

                          10        20
                  ....*....|....*....|.
gi 1370477838  27 GWLYGSFQGNFGWFPCNYVEK 47
Cdd:cd11766    33 GWWRGECNGQVGWFPSNYVTE 53

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF5 and ARHGEF19; ARHGEF5, also called ephexin-3 or TIM (Transforming immortalized mammary oncogene), is a potent activator of RhoA and it plays roles in regulating cell shape, adhesion, and migration. It binds to the SH3 domain of Src and is involved in regulating Src-induced podosome formation. ARHGEF19, also called ephexin-2 or WGEF (weak-similarity GEF), is highly expressed in the intestine, liver, heart and kidney. It activates RhoA, Cdc42, and Rac 1, and has been shown to activate RhoA in the Wnt-PCP (planar cell polarity) pathway. It is involved in the regulation of cell polarity and cytoskeletal reorganization. ARHGEF5 and ARHGEF19 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212873 Cd Length: 55 Bit Score: 38.62 E-value: 5.35e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQENWWFGEVH---GGRGWFPKSYVK 184
Cdd:cd11940     3 QCIRSYKAQENDELTLEKADIIMVRQQSSDGWLEGVRlsdGERGWFPQSHVE 54

Third (or C-terminal) Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212851 [Multi-domain] Cd Length: 58 Bit Score: 38.79 E-value: 5.41e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1370477838 215 GEEYIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGsIGDRS---GIFPSNYVKP 268
Cdd:cd11918     1 RTPYKAVYQYRPQNEDELELREGDRVDVMQQcDDGWFVG-VSRRTqkfGTFPGNYVAP 57

Third Src Homology 3 domain (SH3C) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CD2AP. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212989 [Multi-domain] Cd Length: 57 Bit Score: 38.65 E-value: 5.56e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 288 EIAQVTSAYVASGSEQLSLAPGQLILILKKNT--SGWWQGELQARgkkrqKGWFP 340
Cdd:cd12056     2 EYCKALFHYEGTNEDELDFKEGEIILIISKDTgePGWWKGELNGK-----EGVFP 51

Src homology 3 domain of ephexin-1-like SH3 domain containing Rho guanine nucleotide exchange factors; Members of this family contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and C-terminal SH3 domains. They include the Rho guanine nucleotide exchange factors ARHGEF5, ARHGEF16, ARHGEF19, ARHGEF26, ARHGEF27 (also called ephexin-1), and similar proteins, and are also called ephexins because they interact directly with ephrin A receptors. GEFs interact with Rho GTPases via their DH domains to catalyze nucleotide exchange by stabilizing the nucleotide-free GTPase intermediate. They play important roles in neuronal development. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212727 [Multi-domain] Cd Length: 55 Bit Score: 38.86 E-value: 5.82e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQ-ENWWFGE--VHGGRGWFPKSYV 183
Cdd:cd11793     2 VQCVHAYTAQQPDELTLEEGDVVNVLRKMpDGWYEGErlRDGERGWFPSSYT 53

C-terminal Src Homology 3 domain of the p67phox subunit of NADPH oxidase and similar proteins; This subfamily is composed of p67phox, NADPH oxidase activator 1 (Noxa1), and similar proteins. p67phox, also called Neutrophil cytosol factor 2 (NCF-2), and Noxa1 are homologs and are the cytosolic subunits of the phagocytic (Nox2) and nonphagocytic (Nox1) NADPH oxidase complexes, respectively. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox and Noxa1 play regulatory roles. p67phox contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. Noxa1 has a similar domain architecture except it is lacking the N-terminal SH3 domain. The TPR domain of both binds activated GTP-bound Rac, while the C-terminal SH3 domain of p67phox and Noxa1 binds the polyproline motif found at the C-terminus of p47phox and Noxo1, respectively. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212803 [Multi-domain] Cd Length: 53 Bit Score: 38.66 E-value: 5.83e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11870     1 QVVALHRYEAQGPEDLGFREGDTIDVLSEvNEAWLEGHSDGRVGIFPKCFVV 52

Third Src homology 3 domain (or SH3C) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (SH3C) of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212925 Cd Length: 52 Bit Score: 38.45 E-value: 5.84e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11992     4 ALYPYSSSEPGDLTFNEGEEILVTQKDGEWWTGSIEDRTGIFPSNYVR 51

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212849 [Multi-domain] Cd Length: 59 Bit Score: 38.82 E-value: 5.86e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQENWWF-GEVHGGR--GWFPKSYVKII 186
Cdd:cd11916     5 QALYSYAPQNDDELELRDGDIVDVMEKCDDGWFvGTSRRTKqfGTFPGNYVKLL 58

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 2; SKAP2, also called SKAP55-Related (SKAP55R) or SKAP55 homolog (SKAP-HOM or SKAP55-HOM), is an immune cell-specific adaptor protein that plays an important role in adhesion and migration of B-cells and macrophages. Binding partners include ADAP (adhesion and degranulation-promoting adaptor protein), YopH, SHPS1, and HPK1. SKAP2 has also been identified as a substrate for lymphoid-specific tyrosine phosphatase (Lyp), which has been implicated in a wide variety of autoimmune diseases. It contains a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. Like SKAP1, SKAP2 is expected to bind primarily to a proline-rich region of ADAP through its SH3 domain; its degradation may be regulated by ADAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212978 Cd Length: 53 Bit Score: 38.73 E-value: 5.92e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQEN---WWFGEVHGGRGWFPKSYV 183
Cdd:cd12045     3 QGLWDCTGDQPDELSFKRGDTIYILSKEYNrfgWWVGEMKGTIGLVPKAYI 53

N-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The N-terminal SH3 domain of GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212738 [Multi-domain] Cd Length: 52 Bit Score: 38.49 E-value: 6.22e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGE--EILVTQKDGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11804     1 EAVAKHDFKATAEDELSFKKGSilKVLNMEDDPNWYKAELDGKEGLIPKNYI 52

C2 domain second repeat present in Synaptotagmins 3, 5, 6, 9, and 10; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 3, a member of class 3 synaptotagmins, is located in the brain and localized to the active zone and plasma membrane. It functions as a Ca2+ sensor for fast exocytosis. It, along with synaptotagmins 5,6, and 10, has disulfide bonds at its N-terminus. Synaptotagmin 9, a class 5 synaptotagmins, is located in the brain and localized to the synaptic vesicles. It is thought to be a Ca2+-sensor for dense-core vesicle exocytosis. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 176048 [Multi-domain] Cd Length: 134 Bit Score: 40.95 E-value: 6.26e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISMGSQ-----SYTTRTIQDTLNPKWNFNCQFFIKDLYQDVLCLTL--FDRDQ 873
Cdd:cd08403    14 GRLTLTIIKARNLKAMDITGFSDPYVKVSLMCEgrrlkKKKTSVKKNTLNPTYNEALVFDVPPENVDNVSLIIavVDYDR 93


                  ....*...
gi 1370477838 874 FSPDDFLG 881
Cdd:cd08403    94 VGHNELIG 101

Src homology 3 domain of the Rho guanine nucleotide exchange factor, ephexin-1 (also called NGEF or ARHGEF27); Ephexin-1, also called NGEF (neuronal GEF) or ARHGEF27, activates RhoA, Tac1, and Cdc42 by exchanging bound GDP for free GTP. It is expressed mainly in the brain in a region associated with movement control. It regulates the stability of postsynaptic acetylcholine receptor (AChR) clusters and thus, plays a critical role in the maturation and neurotransmission of neuromuscular junctions. Ephexin-1 directly interacts with the ephrin receptor EphA4 and their coexpression enhances the ability of ephexin-1 to activate RhoA. It is required for normal axon growth and EphA-induced growth cone collapse. Ephexin-1 contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212872 [Multi-domain] Cd Length: 55 Bit Score: 38.77 E-value: 6.41e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGE-VHGG-RGWFPKSYVK 184
Cdd:cd11939     1 QVQCVHPYVSQEPDELSLELADVLNILDKTDDgWIFGErLHDQeRGWFPSSVVE 54

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 1 and similar proteins; This subfamily is composed of SKAP1, SKAP2, and similar proteins. SKAP1 and SKAP2 are immune cell-specific adaptor proteins that play roles in T- and B-cell adhesion, respectively, and are thus important in the migration of T- and B-cells to sites of inflammation and for movement during T-cell conjugation with antigen-presenting cells. Both SKAP1 and SKAP2 bind to ADAP (adhesion and degranulation-promoting adaptor protein), among many other binding partners. They contain a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. The SH3 domain of SKAP1 is necessary for its ability to regulate T-cell conjugation with antigen-presenting cells and the formation of LFA-1 clusters. SKAP1 binds primarily to a proline-rich region of ADAP through its SH3 domain; its degradation is regulated by ADAP. A secondary interaction occurs via the ADAP SH3 domain and the RKxxYxxY motif in SKAP1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212800 Cd Length: 53 Bit Score: 38.57 E-value: 6.43e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQEN---WWFGEVHGGRGWFPKSYV 183
Cdd:cd11866     3 MGLWDCSGNEPDELSFKRGDLIYIISKEYDsfgWWVGELNGKVGLVPKDYL 53

Src Homology 3 domain of Mixed Lineage Kinases 1, 2, and 3; MLKs 1, 2, and 3 are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Little is known about the specific function of MLK1, also called MAP3K9. It is capable of activating the c-Jun N-terminal kinase pathway. Mice lacking both MLK1 and MLK2 are viable, fertile, and have normal life spans. MLK2, also called MAP3K10, is abundant in brain, skeletal muscle, and testis. It functions upstream of the MAPK, c-Jun N-terminal kinase. It binds hippocalcin, a calcium-sensor protein that protects neurons against calcium-induced cell death. Both MLK2 and hippocalcin may be associated with the pathogenesis of Parkinson's disease. MLK3, also called MAP3K11, is highly expressed in breast cancer cells and its signaling through c-Jun N-terminal kinase has been implicated in the migration, invasion, and malignancy of cancer cells. It also functions as a negative regulator of Inhibitor of Nuclear Factor-KappaB Kinase (IKK) and thus, impacts inflammation and immunity. MLKs contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212992 [Multi-domain] Cd Length: 58 Bit Score: 38.59 E-value: 6.49e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTS-----GWWQGELQARgkkrqKGWFPASHV 344
Cdd:cd12059     8 YEASAEDELTLRRGDRVEVLSKDSAvsgdeGWWTGKINDR-----VGIFPSNYV 56

Src homology 3 domain of Endophilin-B2; Endophilin-B2, also called SH3GLB2 (SH3-domain GRB2-like endophilin B2), is a cytoplasmic protein that interacts with the apoptosis inducer Bax. It is overexpressed in prostate cancer metastasis and has been identified as a cancer antigen with potential utility in immunotherapy. Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. Endophilin-B2 forms homo- and heterodimers (with endophilin-B1) through its BAR domain. The related protein endophilin-B1 interacts with amphiphysin 1 and dynamin 1 through its SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212877 Cd Length: 55 Bit Score: 38.44 E-value: 6.76e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD--DPDWWQGEINGVTGLFPSNYVKM 415
Cdd:cd11944     4 VLYDYEAADSSELALLADELITVYSLPgmDPDWLIGERGNQKGKVPVTYLEL 55

Fourth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212751 [Multi-domain] Cd Length: 50 Bit Score: 38.23 E-value: 7.10e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFPKSY 182
Cdd:cd11817     2 AVALYDFTGETEEDLSFQRGDRILVTEHLDaEWSRGRLNGREGIFPRAF 50

Src homology 3 domain of Endophilin-B; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain two endophilin-B isoforms. Endophilin-B proteins are cytoplasmic proteins expressed mainly in the heart, placenta, and skeletal muscle. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212736 [Multi-domain] Cd Length: 52 Bit Score: 38.42 E-value: 7.20e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKD--DPDWWQGEINGVTGLFPSNY 412
Cdd:cd11802     4 VLYDYDAEDSTELSLLADEVITVYELPgmDEDYMMGERGSQRGKVPVAY 52

Second Src Homology 3 domain of FCH and double SH3 domains protein 2; FCHSD2 has a domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. It has only been characterized in silico and its function is unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212827 Cd Length: 56 Bit Score: 38.38 E-value: 7.21e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILV----TQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11894     4 ALYDYEGQTDDELSFPEGAIIRIlnkeNQDDDGFWEGEFNGRIGVFPSVLVE 55

First Src homology 3 domain of Tyrosine kinase substrate (Tks) proteins; Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Vertebrates contain two Tks proteins, Tks4 (Tyr kinase substrate with four SH3 domains) and Tks5 (Tyr kinase substrate with five SH3 domains), which display partially overlapping but non-redundant functions. Both associate with the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. Tks5 interacts with N-WASP and Nck, while Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. Tks proteins contain an N-terminal Phox homology (PX) domain and four or five SH3 domains. This model characterizes the first SH3 domain of Tks proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212948 Cd Length: 53 Bit Score: 38.55 E-value: 7.22e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 292 VTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQargkkRQKGWFPASH 343
Cdd:cd12015     4 VVADYKKQQPNEISLRAGDVVDVIEKNENGWWFVSLE-----DEQGWVPATY 50

C-terminal (Fourth) Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the fourth SH3 domain, located at the C-terminus of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212719 Cd Length: 55 Bit Score: 38.22 E-value: 7.73e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 370 YAANNEDELSFSKGQLINVMNKDDPDWWQGEI--NGVTGLFPSNYVK 414
Cdd:cd11785     8 YPPQSEAELELKEGDIVFVHKKREDGWFKGTLqrTGKTGLFPGSFVE 54

Src Homology 3 domain of Melanoma Inhibitory Activity protein and similar proteins; MIA is a single domain protein that adopts a SH3 domain-like fold; it contains an additional antiparallel beta sheet and two disulfide bonds compared to classical SH3 domains. MIA is secreted from malignant melanoma cells and it plays an important role in melanoma development and invasion. MIA is expressed by chondrocytes in normal tissues and may be important in the cartilage cell phenotype. Unlike classical SH3 domains, MIA does not bind proline-rich ligands. MIA is a member of the recently identified family that also includes MIA-like (MIAL), MIA2, and MIA3 (also called TANGO); the biological functions of this family are not yet fully understood.

Pssm-ID: 212694 Cd Length: 76 Bit Score: 39.00 E-value: 7.80e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 359 HPVCQVIAMYDYAANNEDELSFSKGQLINVMNK---DDPDWWQGEINGVTGL---FPSNYVK 414
Cdd:cd11760     9 NPISRARALEDYHGPDCRFLNFKKGDTIYVYSKlagERQDLWAGSVGGDAGLfgyFPKNLVQ 70

Third Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212858 Cd Length: 57 Bit Score: 38.44 E-value: 7.91e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKDGEWWTGSIGDR---SGIFPSNYVKP 268
Cdd:cd11925     3 YLALYAYKPQKNDELELRKGEMYRVIEKCQDGWFKGTSLRtgvSGVFPGNYVTP 56

Second Src homology 3 domain of Tyrosine kinase substrate with four SH3 domains; Tks4, also called SH3 and PX domain-containing protein 2B (SH3PXD2B) or HOFI, is a Src substrate and scaffolding protein that plays an important role in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. It is required in the formation of functional podosomes, EGF-induced membrane ruffling, and lamellipodia generation. It plays an important role in cellular attachment and cell spreading. Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. It contains an N-terminal Phox homology (PX) domain and four SH3 domains. This model characterizes the second SH3 domain of Tks4. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213009 [Multi-domain] Cd Length: 54 Bit Score: 38.47 E-value: 8.14e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQ-ENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd12076     2 KYTVIYPYTARDQDEINLEKGAVVEVIQKNlEGWWKIRYQGKEGWAPASYLK 53

Src homology 3 domain of Phospholipase C (PLC) gamma 1; PLCgamma1 is widely expressed and is essential in growth and development. It is activated by the TrkA receptor tyrosine kinase and functions as a key regulator of cell differentiation. It is also the predominant PLCgamma in T cells and is required for T cell and NK cell function. PLCs catalyze the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG). Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212903 Cd Length: 60 Bit Score: 38.43 E-value: 8.18e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGDRSGI-FPSNYVK 267
Cdd:cd11970     8 ALFDYKAQREDELTFTKNAIIQnVEKQEGGWWRGDYGGKKQLwFPSNYVE 57

First Src Homology 3 domain (SH3A) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CD2AP. SH3A binds to the PXXXPR motif present in c-Cbl and the cytoplasmic domain of cell adhesion protein CD2. Its interaction with CD2 anchors CD2 at sites of cell contact. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212986 Cd Length: 56 Bit Score: 38.28 E-value: 8.93e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQKDGE--WWTGSIGDRSGIFPSNYVK 267
Cdd:cd12053     1 EYIVEYDYDAVHEDELTIRVGEIIRNVKKLEEegWLEGELNGRRGMFPDNFVK 53

Fourth N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP bind the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212731 Cd Length: 50 Bit Score: 38.17 E-value: 9.07e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEI--LVTQKDGeWWTGSIGDRSGIFPSNY 265
Cdd:cd11797     3 VALYRFQALEPNELDFEVGDRIriIATLEDG-WLEGELKGRRGIFPHRF 50

C2 domain third repeat in Ferlin; Ferlins are involved in vesicle fusion events. Ferlins and other proteins, such as Synaptotagmins, are implicated in facilitating the fusion process when cell membranes fuse together. There are six known human Ferlins: Dysferlin (Fer1L1), Otoferlin (Fer1L2), Myoferlin (Fer1L3), Fer1L4, Fer1L5, and Fer1L6. Defects in these genes can lead to a wide range of diseases including muscular dystrophy (dysferlin), deafness (otoferlin), and infertility (fer-1, fertilization factor-1). Structurally they have 6 tandem C2 domains, designated as (C2A-C2F) and a single C-terminal transmembrane domain, though there is a new study that disputes this and claims that there are actually 7 tandem C2 domains with another C2 domain inserted between C2D and C2E. In a subset of them (Dysferlin, Myoferlin, and Fer1) there is an additional conserved domain called DysF. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the third C2 repeat, C2C, and has a type-II topology.

Pssm-ID: 175985 [Multi-domain] Cd Length: 151 Bit Score: 40.69 E-value: 9.17e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 788 KAYQARS--QKTSGI--GRLMVHVIEATELkackpngkSNPYCEISMGSQSYTTRTIQDTLNPKWN----FNCQFfiKDL 859
Cdd:cd04018     5 KIYRAEDlpQMDSGImaNVKKAFLGEKKEL--------VDPYVEVSFAGQKVKTSVKKNSYNPEWNeqivFPEMF--PPL 74

                          90       100       110
                  ....*....|....*....|....*....|.
gi 1370477838 860 YQdVLCLTLFDRDQFSPDDFLGRTEIPVAKI 890
Cdd:cd04018    75 CE-RIKIQIRDWDRVGNDDVIGTHFIDLSKI 104

Src Homology 3 domain of the p40phox subunit of NADPH oxidase; p40phox, also called Neutrophil cytosol factor 4 (NCF-4), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p40phox positively regulates NADPH oxidase in both phosphatidylinositol-3-phosphate (PI3P)-dependent and PI3P-independent manner. It contains an N-terminal PX domain, a central SH3 domain, and a C-terminal PB1 domain that interacts with p67phox. The SH3 domain of p40phox binds to canonical polyproline and noncanonical motifs at the C-terminus of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212802 Cd Length: 54 Bit Score: 38.24 E-value: 9.18e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSIGDRSGIFPSNYVK 267
Cdd:cd11869     4 ALFDFTGNSKLELNFKAGDVIfLLSRVNKDWLEGTVRGATGIFPLSFVK 52

Second Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212708 [Multi-domain] Cd Length: 52 Bit Score: 38.21 E-value: 9.26e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILV-TQKDGEW-WTGSIGDRSGIFPSNYV 266
Cdd:cd11774     4 ALYDYDKQTEEELSFNEGDTLDVyDDSDSDWiLVGFNGTQFGFVPANYI 52

Src homology 3 domain of Phospholipase C (PLC) gamma 2; PLCgamma2 is primarily expressed in haematopoietic cells, specifically in B cells. It is activated by tyrosine phosphorylation by B cell receptor (BCR) kinases and is recruited to the plasma membrane where its substrate is located. It is required in pre-BCR signaling and in the maturation of B cells. PLCs catalyze the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG). Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212902 Cd Length: 55 Bit Score: 38.28 E-value: 9.44e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELqarGKKRQKgWFPASHVK 345
Cdd:cd11969     8 YRAKRSDELSFCKGALIHNVSKETGGWWKGDY---GGKVQH-YFPSNYVE 53

Src homology 3 domain of RUN and SH3 domain-containing protein 2; RUSC2, also called Iporin or Interacting protein of Rab1, is expressed ubiquitously with highest amounts in the brain and testis. It interacts with the small GTPase Rab1 and the Golgi matrix protein GM130, and may function in linking GTPases to certain intracellular signaling pathways. RUSC proteins are adaptor proteins consisting of RUN, leucine zipper, and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212890 Cd Length: 52 Bit Score: 37.97 E-value: 9.64e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSIGDRSGIFPSNYV 266
Cdd:cd11957     1 EVKALCHHIATEPGQLSFNKGDILQVLSRaDGDWLRCSLGPDSGLVPIAYV 51

C2 domain second repeat present in Synaptotagmin 17; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 17 is located in the brain, kidney, and prostate and is thought to be a peripheral membrane protein. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

Pssm-ID: 176055 [Multi-domain] Cd Length: 135 Bit Score: 40.26 E-value: 9.68e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEATELKACKPNGKSNPYCEISMGS-----QSYTTRTIQDTLNPKWNFNCQFFI--KDLYQDVLCLTLFDRDQ 873
Cdd:cd08410    14 GRLNVDIIRAKQLLQTDMSQGSDPFVKIQLVHglkliKTKKTSCMRGTIDPFYNESFSFKVpqEELENVSLVFTVYGHNV 93

                          90
                  ....*....|..
gi 1370477838 874 FSPDDFLGRTEI 885
Cdd:cd08410    94 KSSNDFIGRIVI 105

First Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212695 [Multi-domain] Cd Length: 57 Bit Score: 38.11 E-value: 9.82e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSIGDRS--GIFPSNYV 266
Cdd:cd11761     5 KVLYSYEAQRPDELTITEGEELeVIEDGDGDGWVKARNKSGevGYVPENYL 55

Src Homology 3 domain of Pak Interactive eXchange factors; PIX proteins are Rho guanine nucleotide exchange factors (GEFs), which activate small GTPases by exchanging bound GDP for free GTP. They act as GEFs for both Cdc42 and Rac 1, and have been implicated in cell motility, adhesion, neurite outgrowth, and cell polarity. Vertebrates contain two proteins from the PIX subfamily, alpha-PIX and beta-PIX. Alpha-PIX, also called ARHGEF6, is localized in dendritic spines where it regulates spine morphogenesis. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. Beta-PIX play roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212810 [Multi-domain] Cd Length: 53 Bit Score: 38.06 E-value: 1.01e-03

                          10        20
                  ....*....|....*....|..
gi 1370477838  25 EPGWLYGSFQGNFGWFPCNYVE 46
Cdd:cd11877    31 EGGWWEGTLNGKTGWFPSNYVK 52

Src Homology 3 domain of CASK interacting protein 2; Caskin2 is a multidomain adaptor protein that contains six ankyrin repeats, a single SH3 domain, tandem sterile alpha motif (SAM) domains, and a long disordered proline-rich region. It shares a domain architecture with Caskin1, but does not bind CASK. The function of Caskin2 is still unknown. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212996 Cd Length: 62 Bit Score: 38.41 E-value: 1.03e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 133 LKAQALCS-WTAKKDNHLNFSKHDIITVLEQQ-ENWWFGEVHGGR------GWFPKSYVKII 186
Cdd:cd12063     1 LKVRALKDfWNLHDPTALNVRAGDVITVLEQHpDGRWKGHIHDSQrgtdrvGYFPPSIVEVI 62

Src Homology 3 domain of Bruton's tyrosine kinase; BTK is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation, and the Tec homology (TH) domain with proline-rich and zinc-binding regions. Btk is expressed in B-cells, and a variety of myeloid cells including mast cells, platelets, neutrophils, and dendrictic cells. It interacts with a variety of partners, from cytosolic proteins to nuclear transcription factors, suggesting a diversity of functions. Stimulation of a diverse array of cell surface receptors, including antigen engagement of the B-cell receptor (BCR), leads to PH-mediated membrane translocation of Btk and subsequent phosphorylation by Src kinase and activation. Btk plays an important role in the life cycle of B-cells including their development, differentiation, proliferation, survival, and apoptosis. Mutations in Btk cause the primary immunodeficiency disease, X-linked agammaglobulinaemia (XLA) in humans. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212839 [Multi-domain] Cd Length: 55 Bit Score: 37.88 E-value: 1.06e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEE-ILVTQKDGEWWTGSIGD-RSGIFPSNYV 266
Cdd:cd11906     4 VALYDYTPMNAQDLQLRKGEEyVILEESNLPWWRARDKNgREGYIPSNYV 53

Src Homology 3 domain of Saccharomyces cerevisiae Nap1-binding protein 2 and similar fungal proteins; This subfamily includes Saccharomyces cerevisiae Nbp2 (Nucleosome assembly protein 1 (Nap1)-binding protein 2), Schizosaccharomyces pombe Skb5, and similar proteins. Nbp2 interacts with Nap1, which is essential for maintaining proper nucleosome structures in transcription and replication. It is also the binding partner of the yeast type II protein phosphatase Ptc1p and serves as a scaffolding protein that brings seven kinases in close contact to Ptc1p. Nbp2 plays a role many cell processes including organelle inheritance, mating hormone response, cell wall stress, mitotic cell growth at elevated temperatures, and high osmolarity. Skb5 interacts with the p21-activated kinase (PAK) homolog Shk1, which is critical for fission yeast cell viability. Skb5 activates Shk1 and plays a role in regulating cell morphology and growth under hypertonic conditions. Nbp2 and Skb5 contain an SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212799 Cd Length: 55 Bit Score: 37.88 E-value: 1.19e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWW--QGEINGVTGLFPSNYVKM 415
Cdd:cd11865     1 RAVALYDFEPEHDNELGFAEGQILFILYKHGQGWLiaEDESGGKTGLVPEEFVSY 55

C2 domain present in NEDL1 (NEDD4-like ubiquitin protein ligase-1); NEDL1 (AKA HECW1(HECT, C2 and WW domain containing E3 ubiquitin protein ligase 1)) is a newly identified HECT-type E3 ubiquitin protein ligase highly expressed in favorable neuroblastomas. In vertebrates it is found primarily in neuronal tissues, including the spinal cord. NEDL1 is thought to normally function in the quality control of cellular proteins by eliminating misfolded proteins. This is thought to be accomplished via a mechanism analogous to that of ER-associated degradation by forming tight complexes and aggregating misfolded proteins that have escaped ubiquitin-mediated degradation. NEDL1, is composed of a C2 domain, two WW domains, and a ubiquitin ligase Hect domain. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 176073 [Multi-domain] Cd Length: 137 Bit Score: 40.08 E-value: 1.20e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 820 GKSNPYCEISM-------------GSQSYTTRTIQDTLNPKWNfNCQFFIKDLYQDVLCLTLfdRDQFSPD-----DFLG 881
Cdd:cd08691    19 FNPDPYVKISIqpgkrhifpalphHGQECRTSIVENTINPVWH-REQFVFVGLPTDVLEIEV--KDKFAKSrpiirRFLG 95

                          90       100
                  ....*....|....*....|....*...
gi 1370477838 882 RTEIPVAKIRT-----EQESKGPMTRRL 904
Cdd:cd08691    96 KLSIPVQRLLErhaigDQELSYTLGRRT 123

Src homology 3 domain of Nitric Oxide Synthase TRaffic INducer; Nostrin is expressed in endothelial and epithelial cells and is involved in the regulation, trafficking and targeting of endothelial NOS (eNOS). It facilitates the endocytosis of eNOS by coordinating the functions of dynamin and the Wiskott-Aldrich syndrome protein (WASP). Increased expression of Nostrin may be correlated to preeclampsia. Nostrin contains an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212757 [Multi-domain] Cd Length: 53 Bit Score: 37.71 E-value: 1.25e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1370477838   2 ENGLENRDTTTIFiysvdEKtvGEPGWLYGSFQGNFGWFPCNYVE 46
Cdd:cd11823    15 ELSLQPGDIIEVH-----EK--QDDGWWLGELNGKKGIFPATYVE 52

C2A domain first repeat present in Synaptotagmins 15 and 17; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. It is thought to be involved in the trafficking and exocytosis of secretory vesicles in non-neuronal tissues and is Ca2+ independent. Human synaptotagmin 15 has 2 alternatively spliced forms that encode proteins with different C-termini. The larger, SYT15a, contains a N-terminal TM region, a putative fatty-acylation site, and 2 tandem C terminal C2 domains. The smaller, SYT15b, lacks the C-terminal portion of the second C2 domain. Unlike most other synaptotagmins it is nearly absent in the brain and rather is found in the heart, lungs, skeletal muscle, and testis. Synaptotagmin 17 is located in the brain, kidney, and prostate and is thought to be a peripheral membrane protein. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 176036 [Multi-domain] Cd Length: 123 Bit Score: 39.55 E-value: 1.25e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 790 YQARSQktsgigRLMVHVIEATELKACKPNGK-SNPYCEIS------MGSQSYTTRtiqDTLNPkwNFNCQFFIKDLYQD 862
Cdd:cd08390     9 YDLEEE------QLTVSLIKARNLPPRTKDVAhCDPFVKVCllpderRSLQSKVKR---KTQNP--NFDETFVFQVSFKE 77

                          90       100       110
                  ....*....|....*....|....*....|
gi 1370477838 863 V----LCLTLFDRDQFSPDDFLGRTEIPVA 888
Cdd:cd08390    78 LqrrtLRLSVYDVDRFSRHCIIGHVLFPLK 107

Src Homology 3 domain of Cdc42-Interacting Protein 4, Bzz1 and similar domains; This subfamily is composed of Cdc42-Interacting Protein 4 (CIP4) and similar proteins such as Formin Binding Protein 17 (FBP17) and FormiN Binding Protein 1-Like (FNBP1L), as well as yeast Bzz1 (or Bzz1p). CIP4 and FNBP1L are Cdc42 effectors that bind Wiskott-Aldrich syndrome protein (WASP) and function in endocytosis. CIP4 and FBP17 bind to the Fas ligand and may be implicated in the inflammatory response. CIP4 may also play a role in phagocytosis. Bzz1 is also a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Members of this subfamily contain an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain as well as at least one C-terminal SH3 domain. Bzz1 contains a second SH3 domain at the C-terminus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212711 [Multi-domain] Cd Length: 55 Bit Score: 37.59 E-value: 1.35e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQ--GEINGVTGLFPSNYVKM 415
Cdd:cd11777     1 ECKALYAFVGSSEGTISMTEGEKLSLVEEDKGDGWTrvRRDTGEEGYVPTSYIRI 55

Src homology 3 domain of SH3 and multiple ankyrin repeat domains protein 3; Shank3, also called ProSAP2 (Proline-rich synapse-associated protein 2), is widely expressed. It plays a role in the formation of dendritic spines and synapses. Haploinsufficiency of the Shank3 gene causes the 22q13 deletion/Phelan-McDermid syndrome, and variants of Shank3 have been implicated in autism spectrum disorder, schizophrenia, and intellectual disability. Shank proteins carry scaffolding functions through multiple sites of protein-protein interaction in its domain architecture, including ankyrin (ANK) repeats, a long proline rich region, as well as SH3, PDZ, and SAM domains. The SH3 domain of Shank binds GRIP, a scaffold protein that binds AMPA receptors and Eph receptors/ligands. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212917 Cd Length: 52 Bit Score: 37.62 E-value: 1.37e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 365 IAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11984     4 IAVKAYSPQGEGEIQLNRGERVKVLSIGEGGFWEGTVKGRTGWFPADCV 52

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase and similar proteins; This subfamily is composed of Rho GTPase activating proteins (GAPs) with similarity to GRAF. Members contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. Although vertebrates harbor four Rho GAPs in the GRAF subfamily including GRAF, GRAF2, GRAF3, and Oligophrenin-1 (OPHN1), only three are included in this model. OPHN1 contains the BAR, PH and GAP domains, but not the C-terminal SH3 domain. GRAF and GRAF2 show GAP activity towards RhoA and Cdc42. GRAF influences Rho-mediated cytoskeletal rearrangements and binds focal adhesion kinase. GRAF2 regulates caspase-activated p21-activated protein kinase-2. The SH3 domain of GRAF and GRAF2 binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212815 [Multi-domain] Cd Length: 54 Bit Score: 37.66 E-value: 1.38e-03

                          10        20
                  ....*....|....*....|..
gi 1370477838  25 EPGWLYGSFQGNFGWFPCNYVE 46
Cdd:cd11882    32 EPGWLEGTLNGRTGLIPENYVE 53

Src Homology 3 domain of Sorting Nexin 9 and similar proteins; Sorting nexins (SNXs) are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. This subfamily consists of SH3 domain containing SNXs including SNX9, SNX18, SNX33, and similar proteins. SNX9 is localized to plasma membrane endocytic sites and acts primarily in clathrin-mediated endocytosis, while SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212697 [Multi-domain] Cd Length: 55 Bit Score: 37.69 E-value: 1.38e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNT-SGWWQGElQARGKkrqKGWFPASHV 344
Cdd:cd11763     8 FDSQPSGELSLRAGEVLTITRQDVgDGWLEGR-NSRGE---VGLFPSSYV 53

First Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the first SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212720 [Multi-domain] Cd Length: 53 Bit Score: 37.34 E-value: 1.44e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 295 AYVASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHVK 345
Cdd:cd11786     7 NYEGKEPGDLSFKKGDIILLRKRIDENWYHGECNG-----KQGFFPASYVQ 52

C2 domain present in Toll-interacting protein (Tollip); Tollip is a part of the Interleukin-1 receptor (IL-1R) signaling pathway. Tollip is proposed to link serine/threonine kinase IRAK to IL-1Rs as well as inhibiting phosphorylation of IRAK. There is a single C2 domain present in Tollip. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

Pssm-ID: 175983 [Multi-domain] Cd Length: 121 Bit Score: 39.62 E-value: 1.47e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 801 GRLMVHVIEAtelKACKPNG--KSNPYCEISMGSQSYTTRTIQD-TLNPKWNFNCQFFIKDLYqDVLCLTLFDRDQFSPD 877
Cdd:cd04016     2 GRLSITVVQA---KLVKNYGltRMDPYCRIRVGHAVYETPTAYNgAKNPRWNKTIQCTLPEGV-DSIYIEIFDERAFTMD 77

                          90
                  ....*....|
gi 1370477838 878 DFLGRTEIPV 887
Cdd:cd04016    78 ERIAWTHITI 87

Src Homology 3 domain of Sorting Nexin 33; SNX33 interacts with Wiskott-Aldrich syndrome protein (WASP) and plays a role in the maintenance of cell shape and cell cycle progression. It modulates the shedding and endocytosis of cellular prion protein (PrP(c)) and amyloid precursor protein (APP). SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX33 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212829 [Multi-domain] Cd Length: 55 Bit Score: 37.63 E-value: 1.52e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 366 AMYDYAANNEDELSFSKGQLINVMNKDDPD-WWQGEIN-GVTGLFPSNYVKM 415
Cdd:cd11896     4 ALYSFQSENKEEINIQENEELVIFSENSLDgWLQGQNSrGETGLFPASYVEI 55

Fifth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212752 [Multi-domain] Cd Length: 50 Bit Score: 37.08 E-value: 1.73e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEIL-VTQKDGEWWTGSIGDRSGIFPSNY 265
Cdd:cd11818     4 ALYDFTGENEDELSFKAGDIITeLESIDEEWMSGELRGKSGIFPKNF 50

Src Homology 3 domain of metazoan osteoclast stimulating factor 1; OSTF1, also named OSF or SH3P2, is a signaling protein containing SH3 and ankyrin-repeat domains. It acts through a Src-related pathway to enhance the formation of osteoclasts and bone resorption. It also acts as a negative regulator of cell motility. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212706 [Multi-domain] Cd Length: 53 Bit Score: 37.28 E-value: 1.79e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 295 AYVASGSEQLSLAPGQLILILKKNTSGWWQGELqargkKRQKGWFPASHV 344
Cdd:cd11772     7 DYEAQHPDELSFEEGDLLYISDKSDPNWWKATC-----GGKTGLIPSNYV 51

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 2; ASAP2 is also called DDEF2 (Development and Differentiation Enhancing Factor 2), AMAP2, centaurin beta-3, or PAG3. It mediates the functions of Arf GTPases vial dual mechanisms: it exhibits GTPase activating protein (GAP) activity towards class I (Arf1) and II (Arf5) Arfs; and it binds class III Arfs (GTP-Arf6) stably without GAP activity. It binds paxillin and is implicated in Fcgamma receptor-mediated phagocytosis in macrophages and in cell migration. ASAP2 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212899 Cd Length: 56 Bit Score: 37.24 E-value: 1.83e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITV-LEQQENWWFGEVHGG---RGWFPKSYV 183
Cdd:cd11966     1 RVKALYNCVADNPDELTFSEGEIIIVdGEEDKEWWIGHIDGEptrRGAFPVSFV 54

First Src Homology 3 domain (SH3A) of CD2-associated protein and similar proteins; This subfamily is composed of the first SH3 domain (SH3A) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3A of both proteins bind to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic domain of the cell adhesion protein CD2. CIN85 SH3A binds to internal proline-rich motifs within the proline-rich region; this intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. CIN85 SH3A has also been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212806 [Multi-domain] Cd Length: 53 Bit Score: 37.25 E-value: 1.84e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:cd11873     8 YDAEEPDELTLKVGDIITNVKKMEEGWWEGTLNGK-----RGMFPDNFVK 52

Second Src Homology 3 domain (SH3B) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CIN85. SH3B has been shown to bind Cbl proline-rich peptides and ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212988 [Multi-domain] Cd Length: 53 Bit Score: 37.28 E-value: 1.90e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 291 QVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARgkkrqKGWFPASHVK 345
Cdd:cd12055     3 QVAFSYLPQNEDELELKVGDIIEVVGEVEEGWWEGVLNGK-----TGMFPSNFIK 52

Second Src homology 3 domain of Tyrosine kinase substrate (Tks) proteins; Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Vertebrates contain two Tks proteins, Tks4 (Tyr kinase substrate with four SH3 domains) and Tks5 (Tyr kinase substrate with five SH3 domains), which display partially overlapping but non-redundant functions. Both associate with the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. Tks5 interacts with N-WASP and Nck, while Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. Tks proteins contain an N-terminal Phox homology (PX) domain and four or five SH3 domains. This model characterizes the second SH3 domain of Tks proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212949 Cd Length: 54 Bit Score: 37.05 E-value: 1.95e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 140 SWTAKKDNHLNFSKHDIITVLEQQ-ENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd12016     8 AYKAENEDEIGFETGVVVEVIQKNlDGWWKIRYQGKEGWAPATYLKK 54

Second Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212835 [Multi-domain] Cd Length: 55 Bit Score: 37.29 E-value: 1.98e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 222 YPYSSVEPGDLTFTEGEEILVTQK--DGeWWTGSIGDRSGIFPSNYV 266
Cdd:cd11902     7 FAYVAEREDELSLVKGSRVTVMEKcsDG-WWRGSYNGQIGWFPSNYV 52

Second Src homology 3 domain of Tyrosine kinase substrate with five SH3 domains; Tks5, also called SH3 and PX domain-containing protein 2A (SH3PXD2A) or Five SH (FISH), is a scaffolding protein and Src substrate that is localized in podosomes, which are electron-dense structures found in Src-transformed fibroblasts, osteoclasts, macrophages, and some invasive cancer cells. It binds and regulates some members of the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. It is required for podosome formation, degradation of the extracellular matrix, and cancer cell invasion. Tks5 contains an N-terminal Phox homology (PX) domain and five SH3 domains. This model characterizes the second SH3 domain of Tks5. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213010 Cd Length: 54 Bit Score: 37.32 E-value: 2.12e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 216 EEYIALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTGSIGDRSGIFPSNYVK 267
Cdd:cd12077     1 EKYVTVQPYTSQGKDEIGFEKGVTVEVIQKNLEgWWYIRYLGKEGWAPASYLK 53

Src homology 3 domain of High osmolarity signaling protein Sho1p; Sho1p (or Sho1), also called SSU81 (Suppressor of SUA8-1 mutation), is a yeast membrane protein that regulates adaptation to high salt conditions by activating the HOG (high-osmolarity glycerol) pathway. High salt concentrations lead to the localization to the membrane of the MAPKK Pbs2, which is then activated by the MAPKK Ste11 and in turn, activates the MAPK Hog1. Pbs2 is localized to the membrane though the interaction of its PxxP motif with the SH3 domain of Sho1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212789 [Multi-domain] Cd Length: 55 Bit Score: 37.01 E-value: 2.22e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 134 KAQALCSWTAKKD--NHLNFSKHDIITVLEQQENWWFGEVHGGR-GWFPKSYVKI 185
Cdd:cd11855     1 RARALYPYDASPDdpNELSFEKGEILEVSDTSGKWWQARKSNGEtGICPSNYLQL 55

C-terminal Src Homology 3 domain of Nebulette and LIM-nebulette (or Lasp2); Nebulette is a cardiac-specific protein that localizes to the Z-disc. It interacts with tropomyosin and is important in stabilizing actin thin filaments in cardiac muscles. Polymorphisms in the nebulette gene are associated with dilated cardiomyopathy, with some mutations resulting in severe heart failure. Nebulette is a 107kD protein that contains an N-terminal acidic region, multiple nebulin repeats, and a C-terminal SH3 domain. LIM-nebulette, also called Lasp2 (LIM and SH3 domain protein 2), is an alternatively spliced variant of nebulette. Although it shares a gene with nebulette, Lasp2 is not transcribed from a muscle-specific promoter, giving rise to its multiple tissue expression pattern with highest amounts in the brain. It can crosslink actin filaments and it affects cell spreading. Lasp2 is a 34kD protein containing an N-terminal LIM domain, three nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212868 [Multi-domain] Cd Length: 58 Bit Score: 37.29 E-value: 2.23e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSI--GDRSGIFPSNYVK 267
Cdd:cd11935     3 YRAMYDYSAQDEDEVSFRDGDYIVNVQPiDEGWMYGTVqrTGRTGMLPANYIE 55

N-terminal Src Homology 3 domain of Ct10 Regulator of Kinase adaptor proteins; CRK adaptor proteins consists of SH2 and SH3 domains, which bind tyrosine-phosphorylated peptides and proline-rich motifs, respectively. They function downstream of protein tyrosine kinases in many signaling pathways started by various extracellular signals, including growth and differentiation factors. Cellular CRK (c-CRK) contains a single SH2 domain, followed by N-terminal and C-terminal SH3 domains. It is involved in the regulation of many cellular processes including cell growth, motility, adhesion, and apoptosis. CRK has been implicated in the malignancy of various human cancers. The N-terminal SH3 domain of CRK binds a number of target proteins including DOCK180, C3G, SOS, and cABL. The CRK family includes two alternatively spliced protein forms, CRKI and CRKII, that are expressed by the CRK gene, and the CRK-like (CRKL) protein, which is expressed by a distinct gene (CRKL). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212692 [Multi-domain] Cd Length: 55 Bit Score: 36.96 E-value: 2.34e-03

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 216 EEYIALYPYSSVEPGDLTFTEGEEILVTQKDGE-WWTG--SIGdRSGIFPSNYV 266
Cdd:cd11758     1 EYVRALFDFPGNDDEDLPFKKGEILTVIRKPEEqWWNArnSEG-KTGMIPVPYV 53

First Src homology 3 domain (or SH3A) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN2 is expected to bind many protein partners, similar to ITSN1 which has been shown to bind Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212921 [Multi-domain] Cd Length: 57 Bit Score: 37.16 E-value: 2.38e-03

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 218 YIALYPYSSVEPGDLTFTEGEEILVTQKD-GE--WWTGSIGDRSGIFPSNYVK 267
Cdd:cd11988     4 YRALYPFEARNHDEMSFNAGDIIQVDEKTvGEpgWLYGSFQGNFGWFPCNYVE 56

Fourth N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP bind the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212731 Cd Length: 50 Bit Score: 36.63 E-value: 2.45e-03

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 364 VIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNY 412
Cdd:cd11797     2 GVALYRFQALEPNELDFEVGDRIRIIATLEDGWLEGELKGRRGIFPHRF 50

Src homology 3 domain of eumetazoan Actin-binding protein 1; Abp1, also called drebrin-like protein, is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a helical domain, and a C-terminal SH3 domain. Mammalian Abp1, unlike yeast Abp1, does not contain an acidic domain that interacts with the Arp2/3 complex. It regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. Abp1 deficiency causes abnormal organ structure and function of the spleen, heart, and lung of mice. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212893 [Multi-domain] Cd Length: 54 Bit Score: 36.99 E-value: 2.57e-03

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGelqaRGKKRQKGWFPASHVKL 346
Cdd:cd11960     8 YQAADDTEISFDPGDIITDIEQIDEGWWRG----TGPDGTYGLFPANYVEL 54

Third Src Homology 3 domain (SH3C) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CD2AP. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212989 [Multi-domain] Cd Length: 57 Bit Score: 37.11 E-value: 2.61e-03

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQ---QENWWFGEVHGGRGWFPKSYVKI 185
Cdd:cd12056     5 KALFHYEGTNEDELDFKEGEIILIISKdtgEPGWWKGELNGKEGVFPDNFVSQ 57

Src Homology 3 domain of Cytokinesis protein 3 and similar proteins; Cytokinesis protein 3 (Cyk3 or Cyk3p) is a component of the actomyosin ring independent cytokinesis pathway in yeast. It interacts with Inn1 and facilitates its recruitment to the bud neck, thereby promoting cytokinesis. Cyk3p contains an N-terminal SH3 domain and a C-terminal transglutaminase-like domain. The Cyk3p SH3 domain binds to the C-terminal proline-rich region of Inn1. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212822 Cd Length: 53 Bit Score: 36.71 E-value: 2.66e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLE-QQENWWFGEV--HGGRGWFPKSYV 183
Cdd:cd11889     1 KVKAVYSWAGETEGDLGFLEGDLIEVLSiGDGSWWSGKLrrNGAEGIFPSNFV 53

Src Homology 3 domain of Insulin Receptor tyrosine kinase Substrate p53, Brain-specific Angiogenesis Inhibitor 1-Associated Protein 2 (BAIAP2)-Like proteins, and similar proteins; Proteins in this family include IRSp53, BAIAP2L1, BAIAP2L2, and similar proteins. They all contain an Inverse-Bin/Amphiphysin/Rvs (I-BAR) or IMD domain in addition to the SH3 domain. IRSp53, also known as BAIAP2, is a scaffolding protein that takes part in many signaling pathways including Cdc42-induced filopodia formation, Rac-mediated lamellipodia extension, and spine morphogenesis. IRSp53 exists as multiple splicing variants that differ mainly at the C-termini. BAIAP2L1, also called IRTKS (Insulin Receptor Tyrosine Kinase Substrate), serves as a substrate for the insulin receptor and binds the small GTPase Rac. It plays a role in regulating the actin cytoskeleton and colocalizes with F-actin, cortactin, VASP, and vinculin. IRSp53 and IRTKS also mediate the recruitment of effector proteins Tir and EspFu, which regulate host cell actin reorganization, to bacterial attachment sites. BAIAP2L2 co-localizes with clathrin plaques but its function has not been determined. The SH3 domains of IRSp53 and IRTKS have been shown to bind the proline-rich C-terminus of EspFu. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212713 [Multi-domain] Cd Length: 57 Bit Score: 36.92 E-value: 2.73e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNKDDPDWWQ---GEINGVTGLFPSNYVK 414
Cdd:cd11779     2 RVKALYPHAAGGETQLSFEEGDVITLLGPEPRDGWHygeNERSGRRGWFPIAYTE 56

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212850 [Multi-domain] Cd Length: 61 Bit Score: 36.89 E-value: 2.86e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1370477838 213 SVGEEYIALYPYSSVEPGDLTFTEGEEILVTQK-DGEWWTGSiGDRS---GIFPSNYVK 267
Cdd:cd11917     2 GGGEPFQALYNYMPRNEDELELREGDVIDVMEKcDDGWFVGT-SRRTkffGTFPGNYVK 59

Second Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212696 [Multi-domain] Cd Length: 57 Bit Score: 36.61 E-value: 2.89e-03

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTS----GWWQGELQARgkkrqKGWFPA 341
Cdd:cd11762     8 YEAQSDEELSFPEGAIIRILRKDDNgvddGWWEGEFNGR-----VGVFPS 52

First Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212854 Cd Length: 55 Bit Score: 36.82 E-value: 3.05e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKII 186
Cdd:cd11921     2 AARLKFDFQAQSPKELTLQKGDIVYIHKEvDKNWLEGEHHGRVGIFPANYVEVL 55

Second Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the second SH3 domain, located C-terminal of the first SH3 domain at the N-terminal half, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212864 Cd Length: 55 Bit Score: 36.82 E-value: 3.12e-03

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 366 AMYDYAANNEDE----LSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11931     4 ALYDFEIKDKDQdkdcLTFTKDEILTVIRRVDENWAEGMLGDKIGIFPILYV 55

Src Homology 3 domain of the p40phox subunit of NADPH oxidase; p40phox, also called Neutrophil cytosol factor 4 (NCF-4), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p40phox positively regulates NADPH oxidase in both phosphatidylinositol-3-phosphate (PI3P)-dependent and PI3P-independent manner. It contains an N-terminal PX domain, a central SH3 domain, and a C-terminal PB1 domain that interacts with p67phox. The SH3 domain of p40phox binds to canonical polyproline and noncanonical motifs at the C-terminus of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212802 Cd Length: 54 Bit Score: 36.70 E-value: 3.15e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKII 186
Cdd:cd11869     1 RAEALFDFTGNSKLELNFKAGDVIFLLSRvNKDWLEGTVRGATGIFPLSFVKII 54

Second Src Homology 3 domain (SH3B) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CD2AP. SH3B binds to c-Cbl in a site (TPSSRPLR is the core binding motif) distinct from the c-Cbl/SH3A binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212987 [Multi-domain] Cd Length: 55 Bit Score: 36.48 E-value: 3.17e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd12054     2 QCKVLFEYVPQNEDELELKVGDIIDINEEvEEGWWSGTLNGKSGLFPSNFVK 53

Src homology 3 domain of SH3 and multiple ankyrin repeat domains (Shank) proteins; Shank proteins carry scaffolding functions through multiple sites of protein-protein interaction in its domain architecture, including ankyrin (ANK) repeats, a long proline rich region, as well as SH3, PDZ, and SAM domains. They bind a variety of membrane and cytosolic proteins, and exist in alternatively spliced isoforms. They are highly enriched in postsynaptic density (PSD) where they interact with the cytoskeleton and with postsynaptic membrane receptors including NMDA and glutamate receptors. They are crucial in the construction and organization of the PSD and dendritic spines of excitatory synapses. There are three members of this family (Shank1, Shank2, Shank3) which show distinct and cell-type specific patterns of expression. Shank1 is brain-specific; Shank2 is found in neurons, glia, endocrine cells, liver, and kidney; Shank3 is widely expressed. The SH3 domain of Shank binds GRIP, a scaffold protein that binds AMPA receptors and Eph receptors/ligands. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212766 Cd Length: 50 Bit Score: 36.65 E-value: 3.17e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVLEQQE-NWWFGEVHGGRGWFP 179
Cdd:cd11832     4 AVKSYSPQEEGEISLHKGDRVKVLSIGEgGFWEGSVRGRTGWFP 47

Src Homology 3 domain of Amphiphysin and related domains; Amphiphysins function primarily in endocytosis and other membrane remodeling events. They exist in several isoforms and mammals possess two amphiphysin proteins from distinct genes. Amphiphysin I proteins, enriched in the brain and nervous system, contain domains that bind clathrin, Adaptor Protein complex 2 (AP2), dynamin, and synaptojanin. They function in synaptic vesicle endocytosis. Human autoantibodies to amphiphysin I hinder GABAergic signaling and contribute to the pathogenesis of paraneoplastic stiff-person syndrome. Some amphiphysin II isoforms, also called Bridging integrator 1 (Bin1), are localized in many different tissues and may function in intracellular vesicle trafficking. In skeletal muscle, Bin1 plays a role in the organization and maintenance of the T-tubule network. Mutations in Bin1 are associated with autosomal recessive centronuclear myopathy. Amphiphysins contain an N-terminal BAR domain with an additional N-terminal amphipathic helix (an N-BAR), a variable central domain, and a C-terminal SH3 domain. The SH3 domain of amphiphysins bind proline-rich motifs present in binding partners such as dynamin, synaptojanin, and nsP3. It also belongs to a subset of SH3 domains that bind ubiquitin in a site that overlaps with the peptide binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212724 [Multi-domain] Cd Length: 64 Bit Score: 36.92 E-value: 3.22e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVL------EQQENWWFG--EVHGGRGWFPKSYVKII 186
Cdd:cd11790     4 KVRATHDYTAEDTDELTFEKGDVILVIpfddpeEQDEGWLMGvkESTGCRGVFPENFTERI 64

Third Src homology 3 domain of Tyrosine kinase substrate (Tks) proteins; Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Vertebrates contain two Tks proteins, Tks4 (Tyr kinase substrate with four SH3 domains) and Tks5 (Tyr kinase substrate with five SH3 domains), which display partially overlapping but non-redundant functions. Both associate with the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. Tks5 interacts with N-WASP and Nck, while Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. Tks proteins contain an N-terminal Phox homology (PX) domain and four or five SH3 domains. This model characterizes the third SH3 domain of Tks proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212950 Cd Length: 53 Bit Score: 36.66 E-value: 3.22e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 298 ASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHV 344
Cdd:cd12017    10 ATIQDGISFQKGQKVEVIDKNPSGWWYVKIDG-----KEGWAPSSYI 51

C-terminal (Fourth) Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the fourth SH3 domain, located at the C-terminus of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212719 Cd Length: 55 Bit Score: 36.68 E-value: 3.32e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 291 QVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQARGKkrqKGWFPASHVK 345
Cdd:cd11785     3 RVIVPYPPQSEAELELKEGDIVFVHKKREDGWFKGTLQRTGK---TGLFPGSFVE 54

Src homology 3 domain of Protein arginine N-methyltransferase 2; PRMT2, also called HRMT1L1, belongs to the arginine methyltransferase protein family. It functions as a coactivator to both estrogen receptor alpha (ER-alpha) and androgen receptor (AR), presumably through arginine methylation. The ER-alpha transcription factor is involved in cell proliferation, differentiation, morphogenesis, and apoptosis, and is also implicated in the development and progression of breast cancer. PRMT2 and its variants are upregulated in breast cancer cells and may be involved in modulating the ER-alpha signaling pathway during formation of breast cancer. PRMT2 also plays a role in regulating the function of E2F transcription factors, which are critical cell cycle regulators, by binding to the retinoblastoma gene product (RB). It contains an N-terminal SH3 domain and an AdoMet binding domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212740 [Multi-domain] Cd Length: 53 Bit Score: 36.60 E-value: 3.33e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEILVTQKDG-EWWTGSIGDRSGIFPSNYVKP 268
Cdd:cd11806     1 EYVAIADFVATDDSQLSFESGDKLLVLRKPSvDWWWAEHNGCCGYIPASHLHQ 53

First or N-terminal Src homology 3 domain of the p47phox subunit of NADPH oxidase, also called Neutrophil Cytosolic Factor 1; p47phox, or NCF1, is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox), which plays a key role in the ability of phagocytes to defend against bacterial infections. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p47phox is required for activation of NADH oxidase and plays a role in translocation. It contains an N-terminal Phox homology (PX) domain, tandem SH3 domains (N-SH3 and C-SH3), a polybasic/autoinhibitory region, and a C-terminal proline-rich region (PRR). This model characterizes the first SH3 domain (or N-SH3) of p47phox. In its inactive state, the tandem SH3 domains interact intramolecularly with the autoinhibitory region; upon activation, the tandem SH3 domains are exposed through a conformational change, resulting in their binding to the PRR of p22phox and the activation of NADPH oxidase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212954 [Multi-domain] Cd Length: 53 Bit Score: 36.47 E-value: 3.39e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYVK 184
Cdd:cd12021     3 RAIADYEKSSKSEMALKTGDVVEVVEKSENgWWFCQLKAKRGWVPASYLE 52

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding proteins; CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes including migration, chemotaxis, apoptosis, differentiation, and progenitor cell function. They mediate the signaling of integrins at focal adhesions where they localize, and thus, regulate cell invasion and survival. Over-expression of these proteins is implicated in poor prognosis, increased metastasis, and resistance to chemotherapeutics in many cancers such as breast, lung, melanoma, and glioblastoma. CAS proteins have also been linked to the pathogenesis of inflammatory disorders, Alzheimer's, Parkinson's, and developmental defects. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. Vertebrates contain four CAS proteins: BCAR1 (or p130Cas), NEDD9 (or HEF1), EFS (or SIN), and CASS4 (or HEPL). The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212778 Cd Length: 56 Bit Score: 36.56 E-value: 3.49e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE----WWTGSIGDRSGIFPSNYVK 267
Cdd:cd11844     4 ALYDNVAESPDELAFRRGDILTVLEQNTAglegWWLCSLRGRQGIAPGNRLK 55

First C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212895 [Multi-domain] Cd Length: 54 Bit Score: 36.31 E-value: 3.52e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGElqarGKKRQKGWFPASHVKL 346
Cdd:cd11962     2 AVVLYDYEKDEDNEIELVEGEIVTNIEMVDEDWWMGT----NSKGESGLFPSNYVEL 54

Third Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212750 [Multi-domain] Cd Length: 51 Bit Score: 36.23 E-value: 3.56e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGRGWFPKSYV 183
Cdd:cd11816     1 RCVARFDFEGEQEDELSFSEGDVITLKEYvGEEWAKGELNGKIGIFPLNFV 51

Src homology 3 domains; Src homology 3 (SH3) domains bind to target proteins through sequences containing proline and hydrophobic amino acids. Pro-containing polypeptides may bind to SH3 domains in 2 different binding orientations.

Pssm-ID: 214620 [Multi-domain] Cd Length: 56 Bit Score: 36.36 E-value: 3.61e-03

                           10        20        30
                   ....*....|....*....|....*....|...
gi 1370477838   15 IYSVDEKTvgEPGWLYGSFQ-GNFGWFPCNYVE 46
Cdd:smart00326  26 IITVLEKS--DDGWWKGRLGrGKEGLFPSNYVE 56

C-terminal (or second) Src homology 3 domain of VAV3 protein; VAV3 is ubiquitously expressed and functions as a phosphorylation-dependent guanine nucleotide exchange factor (GEF) for RhoA, RhoG, and Rac1. It has been implicated to function in the hematopoietic, bone, cerebellar, and cardiovascular systems. VAV3 is essential in axon guidance in neurons that control blood pressure and respiration. It is overexpressed in prostate cancer cells and it plays a role in regulating androgen receptor transcriptional activity. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212911 [Multi-domain] Cd Length: 56 Bit Score: 36.54 E-value: 3.74e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGE--WWTGSIGDRSGIFPSNYVK 267
Cdd:cd11978     4 IARYDFCARDMRELSLLKGDVVKIYTKMSTngWWRGEVNGRVGWFPSTYVE 54

Src homology 3 domain of Src-Like Adaptor Protein 2; SLAP2 plays a role in c-Cbl-dependent regulation of CSF1R, a tyrosine kinase important for myeloid cell growth and differentiation. It has been shown to interact with CSF1R, c-Cbl, LAT, CD247, and Zap70. SLAPs are adaptor proteins with limited similarity to Src family tyrosine kinases. They contain an N-terminal SH3 domain followed by an SH2 domain, and a unique C-terminal sequence. They function in regulating the signaling, ubiquitination, and trafficking of T-cell receptor (TCR) and B-cell receptor (BCR) components. The SH3 domain of SLAP forms a complex with v-Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212944 Cd Length: 55 Bit Score: 36.26 E-value: 3.82e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 363 QVIAMYDYAANNEDELSFSKGQLINVMNkDDPDWWQ--GEINGVTGLFPSNYV 413
Cdd:cd12011     1 VAVALCNFPSGGPTELSIRMGEQLTILS-EDGDWWKvsSAVTGRECYIPSNYV 52

Src Homology 3 domain of Class A and B Dedicator of Cytokinesis proteins; DOCK proteins are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. They are divided into four classes (A-D) based on sequence similarity and domain architecture: class A includes Dock1, 2 and 5; class B includes Dock3 and 4; class C includes Dock6, 7, and 8; and class D includes Dock9, 10 and 11. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. This subfamily includes only Class A and B DOCKs, which also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus. Class A/B DOCKs are mostly specific GEFs for Rac, except Dock4 which activates the Ras family GTPase Rap1, probably indirectly through interaction with Rap regulatory proteins. The SH3 domain of class A/B DOCKs have been shown to bind Elmo, a scaffold protein that promotes GEF activity of DOCKs by releasing DHR-2 autoinhibition by the intramolecular SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212805 [Multi-domain] Cd Length: 56 Bit Score: 36.41 E-value: 3.87e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGEWWTG-SIGDRS--GIFPSNYVKPK 269
Cdd:cd11872     3 VAIYNFQGDGEHQLSLQVGDTVQILEECEGWYRGfSLRNKSlkGIFPKSYVHIK 56

C-terminal (or second) Src homology 3 domain of VAV proteins; VAV proteins function both as cytoplasmic guanine nucleotide exchange factors (GEFs) for Rho GTPases and scaffold proteins and they play important roles in cell signaling by coupling cell surface receptors to various effector functions. They play key roles in processes that require cytoskeletal reorganization including immune synapse formation, phagocytosis, cell spreading, and platelet aggregation, among others. Vertebrates have three VAV proteins (VAV1, VAV2, and VAV3). VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212764 [Multi-domain] Cd Length: 54 Bit Score: 36.45 E-value: 3.96e-03

                          10        20
                  ....*....|....*....|....*
gi 1370477838  23 VGEPGWLYGSFQGNFGWFPCNYVEK 47
Cdd:cd11830    30 KGQQGWWRGEINGRIGWFPSTYVEE 54

Src homology 3 domain of Slit-Robo GTPase Activating Proteins; Slit-Robo GTPase Activating Proteins (srGAPs) are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. Vertebrates contain three isoforms of srGAPs (srGAP1-3), all of which are expressed during embryonic and early development in the nervous system but with different localization and timing. A fourth member has also been reported (srGAP4, also called ARHGAP4). srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212743 [Multi-domain] Cd Length: 53 Bit Score: 36.23 E-value: 4.35e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQQEN-WWFGEVHGGRGWFPKSYV 183
Cdd:cd11809     2 ATAQFDYTGRSERELSFKKGDSLTLYRQVSDdWWRGQLNGQDGLVPHKYI 51

Src homology 3 domain of SH3 protein interacting with Nck, 90 kDa (SPIN90); SPIN90 is also called NCK interacting protein with SH3 domain (NCKIPSD), Dia-interacting protein (DIP), 54 kDa vimentin-interacting protein (VIP54), or WASP-interacting SH3-domain protein (WISH). It is an F-actin binding protein that regulates actin polymerization and endocytosis. It associates with the Arp2/3 complex near actin filaments and determines filament localization at the leading edge of lamellipodia. SPIN90 is expressed in the early stages of neuronal differentiation and plays a role in regulating growth cone dynamics and neurite outgrowth. It also interacts with IRSp53 and regulates cell motility by playing a role in the formation of membrane protrusions. SPIN90 contains an N-terminal SH3 domain, a proline-rich domain, and a C-terminal VCA (verprolin-homology and cofilin-like acidic) domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212783 [Multi-domain] Cd Length: 53 Bit Score: 36.14 E-value: 4.35e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQ-QENWWFGEVHGGR-GWFPKSYVK 184
Cdd:cd11849     3 RALYDFKSAEPNTLSFSEGETFLLLERsNAHWWLVTNHSGEtGYVPANYVK 53

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 1; ASAP1 is also called DDEF1 (Development and Differentiation Enhancing Factor 1), AMAP1, centaurin beta-4, or PAG2. an Arf GTPase activating protein (GAP) with activity towards Arf1 and Arf5 but not Arf6. However, it has been shown to bind GTP-Arf6 stably without GAP activity. It has been implicated in cell growth, migration, and survival, as well as in tumor invasion and malignancy. It binds paxillin and cortactin, two components of invadopodia which are essential for tumor invasiveness. It also binds focal adhesion kinase (FAK) and the SH2/SH3 adaptor CrkL. ASAP1 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212898 [Multi-domain] Cd Length: 57 Bit Score: 36.14 E-value: 4.45e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1370477838 298 ASGSEQLSLAPGQLILILKKNTSGWWQGELQarGKKRQKGWFPASHVKLL 347
Cdd:cd11965    10 ADNDDELTFVEGEVIIVTGEEDQEWWIGHIE--GQPERKGVFPVSFVHIL 57

Second Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212856 [Multi-domain] Cd Length: 57 Bit Score: 36.43 E-value: 4.55e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 217 EYIALYPYSSVEPGDLTFTEGEEI-LVTQKDGEWWTGSI--GDRSGIFPSNYVK 267
Cdd:cd11923     2 EAVAKYNFNADTNVELSLRKGDRVvLLKQVDQNWYEGKIpgTNRQGIFPVSYVE 55

Src Homology 3 domain of Sorting nexin 9; Sorting nexin 9 (SNX9), also known as SH3PX1, is a cytosolic protein that interacts with proteins associated with clathrin-coated pits such as Cdc-42-associated tyrosine kinase 2 (ACK2). It binds class I polyproline sequences found in dynamin 1/2 and the WASP/N-WASP actin regulators. SNX9 is localized to plasma membrane endocytic sites and acts primarily in clathrin-mediated endocytosis. Its array of interacting partners suggests that SNX9 functions at the interface between endocytosis and actin cytoskeletal organization. SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX9 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212831 Cd Length: 57 Bit Score: 36.38 E-value: 4.60e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 367 MYDYAAN-NEDELSFSKGQLINVMNKD-DPDWWQGEIN-GVTGLFPSNYVKM 415
Cdd:cd11898     5 LYDFAAEpGNNELTVKEGEIITVTNPNvGGGWIEAKNSqGERGLVPTDYVEI 56

C-terminal Src Homology 3 domain of NADPH oxidase activator 1; Noxa1 is a homolog of p67phox and is a cytosolic subunit of the nonphagocytic NADPH oxidase complex Nox1, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Noxa1 is co-expressed with Nox1 in colon, stomach, uterus, prostate, and vascular smooth muscle cells, consistent with its regulatory role. It does not interact with p40phox, unlike p67phox, making Nox1 activity independent of p40phox, unlike Nox2. Noxa1 contains TPR, PB1, and C-terminal SH3 domains, but lacks the central SH3 domain that is present in p67phox. The TPR domain binds activated GTP-bound Rac. The C-terminal SH3 domain binds the polyproline motif found at the C-terminus of Noxo1, a homolog of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212980 Cd Length: 53 Bit Score: 35.95 E-value: 4.72e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 137 ALCSWTAKKDNHLNFSKHDIITVL-EQQENWWFGEVHGGRGWFPKSYV 183
Cdd:cd12047     4 AQHDYSAQGPEDLEFSQGDTIDILsEVNQEWLEGHCDGRIGIFPKCFA 51

Src Homology 3 domain of Brain-specific Angiogenesis Inhibitor 1-Associated Protein 2-Like 1, also called Insulin Receptor Tyrosine Kinase Substrate (IRTKS); BAIAP2L1 or IRTKS is widely expressed, serves as a substrate for the insulin receptor, and binds the small GTPase Rac. It plays a role in regulating the actin cytoskeleton and colocalizes with F-actin, cortactin, VASP, and vinculin. BAIAP2L1 expression leads to the formation of short actin bundles, distinct from filopodia-like protrusions induced by the expression of the related protein IRSp53. IRTKS mediates the recruitment of effector proteins Tir and EspFu, which regulate host cell actin reorganization, to bacterial attachment sites. It contains an N-terminal IMD or Inverse-Bin/Amphiphysin/Rvs (I-BAR) domain, an SH3 domain, and a WASP homology 2 (WH2) actin-binding motif at the C-terminus. The SH3 domain of IRTKS has been shown to bind the proline-rich C-terminus of EspFu. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212846 Cd Length: 58 Bit Score: 36.05 E-value: 4.81e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1370477838 299 SGSEQLSLAPGQ-LILILKKNTSGWWQGELQARGkkrQKGWFPASHVKL 346
Cdd:cd11913    13 NNKTLLSFAQGDvITLLIPEEKDGWLYGEHDTTK---ARGWFPSSYTRP 58

C-terminal (or second) Src homology 3 domain of VAV2 protein; VAV2 is widely expressed and functions as a guanine nucleotide exchange factor (GEF) for RhoA, RhoB and RhoG and also activates Rac1 and Cdc42. It is implicated in many cellular and physiological functions including blood pressure control, eye development, neurite outgrowth and branching, EGFR endocytosis and degradation, and cell cluster morphology, among others. It has been reported to associate with Nek3. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212910 [Multi-domain] Cd Length: 58 Bit Score: 36.14 E-value: 4.92e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1370477838 135 AQALCSWTAKKDNHLNFSKHDIITVLEQ---QENWWFGEVHGGRGWFPKSYVK 184
Cdd:cd11977     3 AVARYNFAARDMRELSLREGDVVRIYSRiggDQGWWKGETNGRIGWFPSTYVE 55

Src homology 3 domain of Cortactin; Cortactin was originally identified as a substrate of Src kinase. It is an actin regulatory protein that binds to the Arp2/3 complex and stabilizes branched actin filaments. It is involved in cellular processes that affect cell motility, adhesion, migration, endocytosis, and invasion. It is expressed ubiquitously except in hematopoietic cells, where the homolog hematopoietic lineage cell-specific 1 (HS1) is expressed instead. Cortactin contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region interacts with the Arp2/3 complex and F-actin, and is crucial in regulating branched actin assembly. Cortactin also serves as a scaffold and provides a bridge to the actin cytoskeleton for membrane trafficking and signaling proteins that bind to its SH3 domain. Binding partners for the SH3 domain of cortactin include dynamin2, N-WASp, MIM, FGD1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212892 [Multi-domain] Cd Length: 53 Bit Score: 35.86 E-value: 5.04e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGElqARGkkrQKGWFPASHVKL 346
Cdd:cd11959     8 YQAADDDEISFDPDDIITNIEMIDEGWWRGV--CRG---KYGLFPANYVEL 53

Src Homology 3 domain of alpha-Pak Interactive eXchange factor; Alpha-PIX, also called Rho guanine nucleotide exchange factor 6 (ARHGEF6) or Cool (Cloned out of Library)-2, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and is localized in dendritic spines where it regulates spine morphogenesis. It controls dendritic length and spine density in the hippocampus. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212993 Cd Length: 58 Bit Score: 36.13 E-value: 5.25e-03

                          10        20
                  ....*....|....*....|....*...
gi 1370477838  23 VGEPGWLYGSFQGNFGWFPCNYVEKMPS 50
Cdd:cd12060    31 VEEGGWWEGTLNGKTGWFPSNYVREIKS 58

C-terminal (or second) Src homology 3 domain of VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and it plays an important role in the development and activation of B and T cells. It is activated by tyrosine phosphorylation to function as a guanine nucleotide exchange factor (GEF) for Rho GTPases following cell surface receptor activation, triggering various effects such as cytoskeletal reorganization, transcription regulation, cell cycle progression, and calcium mobilization. It also serves as a scaffold protein and has been shown to interact with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76, and Syk, among others. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The C-terminal SH3 domain of Vav1 interacts with a wide variety of proteins including cytoskeletal regulators (zyxin), RNA-binding proteins (Sam68), transcriptional regulators, viral proteins, and dynamin 2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212909 [Multi-domain] Cd Length: 54 Bit Score: 36.08 E-value: 5.41e-03

                          10        20
                  ....*....|....*....|....
gi 1370477838  24 GEPGWLYGSFQGNFGWFPCNYVEK 47
Cdd:cd11976    31 GQQGWWRGEIYGRVGWFPANYVEE 54

C2 domain first repeat present in Synaptotagmin-like proteins 4 and 5; All Slp members basically share an N-terminal Slp homology domain (SHD) and C-terminal tandem C2 domains (named the C2A domain and the C2B domain) with the SHD and C2 domains being separated by a linker sequence of various length. SHD of Slp (except for the Slp4-SHD) function as a specific Rab27A/B-binding domain. In addition to Slp, rabphilin, Noc2, and Munc13-4 also function as Rab27-binding proteins. It has been demonstrated that Slp4/granuphilin promotes dense-core vesicle exocytosis. The C2A domain of Slp4 is Ca2+ dependent. Slp5 mRNA has been shown to be restricted to human placenta and liver suggesting a role in Rab27A-dependent membrane trafficking in specific tissues. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 175995 [Multi-domain] Cd Length: 125 Bit Score: 37.80 E-value: 5.64e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 794 SQKTSGigrLMVHVIEATELkACKPNGK--SNPYCEISM----GSQSYTTRTIQ-DTLNPKWNFNCQFFIKD--LYQDVL 864
Cdd:cd04029    11 DYKTQS---LNVHVKECRNL-AYGDEAKkrSNPYVKTYLlpdkSRQSKRKTSIKrNTTNPVYNETLKYSISHsqLETRTL 86

                          90       100
                  ....*....|....*....|..
gi 1370477838 865 CLTLFDRDQFSPDDFLGRTEIP 886
Cdd:cd04029    87 QLSVWHYDRFGRNTFLGEVEIP 108

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 1; SKAP1, also called SKAP55 (Src kinase-associated protein of 55kDa), is an immune cell-specific adaptor protein that plays an important role in T-cell adhesion, migration, and integrin clustering. It is expressed exclusively in T-lymphocytes, mast cells, and macrophages. Binding partners include ADAP (adhesion and degranulation-promoting adaptor protein), Fyn, Riam, RapL, and RasGRP. It contains a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. The SH3 domain of SKAP1 is necessary for its ability to regulate T-cell conjugation with antigen-presenting cells and the formation of LFA-1 clusters. SKAP1 binds primarily to a proline-rich region of ADAP through its SH3 domain; its degradation is regulated by ADAP. A secondary interaction occurs via the ADAP SH3 domain and the RKxxYxxY motif in SKAP1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212977 Cd Length: 53 Bit Score: 35.99 E-value: 5.94e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 136 QALCSWTAKKDNHLNFSKHDIITVLEQQEN---WWFGEVHGGRGWFPKSYV 183
Cdd:cd12044     3 QGLWDCFGDNPDELSFQRGDLIYILSKEYNmygWWVGELNGIVGIVPKDYL 53

Second Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212834 [Multi-domain] Cd Length: 55 Bit Score: 35.78 E-value: 5.98e-03

                          10
                  ....*....|....*....
gi 1370477838  27 GWLYGSFQGNFGWFPCNYV 45
Cdd:cd11901    35 GWWRGSYNGQVGWFPSNYV 53

Src homology 3 domain of Abl Interactor 1; Abi1, also called e3B1, is a central regulator of actin cytoskeletal reorganization through interactions with many protein complexes. It is part of WAVE, a nucleation-promoting factor complex, that links Rac 1 activation to actin polymerization causing lamellipodia protrusion at the plasma membrane. Abi1 interact with formins to promote protrusions at the leading edge of motile cells. It also is a target of alpha4 integrin, regulating membrane protrusions at sites of integrin engagement. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212904 [Multi-domain] Cd Length: 59 Bit Score: 36.15 E-value: 5.99e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQENWWF-GEVHGGRGWFPKSYVKII 186
Cdd:cd11971     1 KVVAIYDYSKDKDDELSFMEGAIIYVIKKNDDGWYeGVCNGVTGLFPGNYVESI 54

Ca2+-dependent lipid-binding protein, contains C2 domain [General function prediction only];

Pssm-ID: 227371 [Multi-domain] Cd Length: 1227 Bit Score: 40.51 E-value: 6.07e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838  779 IDTEKKKREKAYqarsqKTSGIGRLMVHVIEATELKACKPNGKSNPYCEISMGSQS-YTTRTIQDTLNPKWNfncQFFIK 857
Cdd:COG5038    694 IYNAGGSSSKTV-----YDTPIGAIRVSVRKANDLRNEIPGGKSDPYATVLVNNLVkYRTIYGSSTLNPIWN---EILYV 765

                           90       100       110       120       130       140       150
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1370477838  858 DLYQDVLCLTLFDRD--QFSPDDFLGRTEIPVAKIRTEQESKGPM--------TRRLLLHEVP---TGEVWVRF 918
Cdd:COG5038    766 PVTSKNQRLTLECMDyeESGDDRNLGEVNINVSNVSKKDEDSALMetidgaeeTGKLSLTGKKvkgTITYKCRF 839

Src homology 3 domain of the Rho guanine nucleotide exchange factor ARHGEF9; ARHGEF9, also called PEM2 or collybistin, selectively activates Cdc42 by exchanging bound GDP for free GTP. It is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. Mutations in the ARHGEF9 gene cause X-linked mental retardation with associated features like seizures, hyper-anxiety, aggressive behavior, and sensory hyperarousal. ARHGEF9 contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212908 Cd Length: 62 Bit Score: 36.23 E-value: 6.14e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSGWWQGELQargkkRQKGWFPASHVKL 346
Cdd:cd11975     7 AEAVWDHVTMANRELAFKAGDVIKVLDASNKDWWWGQID-----DEEGWFPASFVRL 58

Src Homology 3 domain of Class A Dedicator of Cytokinesis proteins 1 and 5; Dock1, also called Dock180, and Dock5 are class A DOCKs and are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. Dock1 interacts with the scaffold protein Elmo and the resulting complex functions upstream of Rac in many biological events including phagocytosis of apoptotic cells, cell migration and invasion. Dock5 functions upstream of Rac1 to regulate osteoclast function. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. Class A DOCKs also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus; they are specific GEFs for Rac. The SH3 domain of Dock1 binds to DHR-2 in an autoinhibitory manner; binding of Elmo to the SH3 domain of Dock1 exposes the DHR-2 domain and promotes GEF activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212984 [Multi-domain] Cd Length: 56 Bit Score: 35.95 E-value: 6.26e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKkNTSGWWQGelQARGKKRQKGWFPASHVKL 346
Cdd:cd12051     8 YDARGPDELSLQIGDTVHILE-TYEGWYRG--YTLRKKSKKGIFPASYIHL 55

Src Homology 3 domain of eumetazoan Peroxisomal biogenesis factor 13; PEX13 is a peroxin and is required for protein import into the peroxisomal matrix and membrane. It is an integral membrane protein that is essential for the localization of PEX14 and the import of proteins containing the peroxisome matrix targeting signals, PTS1 and PTS2. Mutations of the PEX13 gene in humans lead to a wide range of peroxisome biogenesis disorders (PBDs), the most severe of which is known as Zellweger syndrome (ZS), a severe multisystem disorder characterized by hypotonia, psychomotor retardation, and neuronal migration defects. PEX13 contains two transmembrane regions and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212798 Cd Length: 58 Bit Score: 35.68 E-value: 6.83e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 219 IALYPYSSVEPGDLTFTEGEEILVTQKDGE-----WWTGSIGD-RSGIFPSNYVK 267
Cdd:cd11864     3 RAEYDFVAESEDELSFRAGDKLRLAPKELQprvrgWLLATVDGqKIGLVPANYVK 57

Src homology 3 domain of the CAS (Crk-Associated Substrate) scaffolding protein family member, Breast Cancer Anti-estrogen Resistance 1; BCAR1, also called p130cas or CASS1, is the founding member of the CAS family of scaffolding proteins and was originally identified through its ability to associate with Crk. The name BCAR1 was designated because the human gene was identified in a screen for genes that promote resistance to tamoxifen. It is widely expressed and its deletion is lethal in mice. It plays a role in regulating cell motility, survival, proliferation, transformation, cancer progression, and bacterial pathogenesis. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212934 Cd Length: 68 Bit Score: 36.17 E-value: 6.91e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1370477838 220 ALYPYSSVEPGDLTFTEGEEILVTQKDGE----WWTGSIGDRSGIFPSNYVK 267
Cdd:cd12001     7 ALYDNVAESPDELSFRKGDIMTVLERDTQgldgWWLCSLHGRQGIVPGNRLK 58

Second Src homology 3 domain (or SH3B) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212922 [Multi-domain] Cd Length: 52 Bit Score: 35.46 E-value: 7.13e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1370477838 290 AQVTSAYVASGSEQLSLAPGQLILILKKNTSgWWQGELQArgkkrQKGWFPASHVKL 346
Cdd:cd11989     2 AQALYPWRAKKDNHLNFNKNDVITVLEQQDM-WWFGEVQG-----QKGWFPKSYVKL 52

Third Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. The third SH3 domain of Sla1p can bind ubiquitin while retaining the ability to bind proline-rich ligands; monoubiquitination of target proteins signals internalization and sorting through the endocytic pathway. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212709 [Multi-domain] Cd Length: 57 Bit Score: 35.76 E-value: 7.20e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 288 EIAQVTSAYVASGSEQLSLAPGQLILIL-KKNTSGWWQGELQARGkkrQKGWFPASHVKL 346
Cdd:cd11775     1 KRGKVLYDFDAQSDDELTVKEGDVVYILdDKKSKDWWMVENVSTG---KEGVVPASYIEI 57

Src homology 3 domain of Abl Interactor 2; Abi2 is highly expressed in the brain and eye. It regulates actin cytoskeletal reorganization at adherens junctions and dendritic spines, which is important in cell morphogenesis, migration, and cognitive function. Mice deficient with Abi2 show defects in orientation and migration of lens fibers, neuronal migration, dendritic spine morphology, as well as deficits in learning and memory. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212905 [Multi-domain] Cd Length: 61 Bit Score: 35.76 E-value: 7.28e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 134 KAQALCSWTAKKDNHLNFSKHDIITVLEQQENWWF-GEVHGGRGWFPKSYVKIIPG 188
Cdd:cd11972     4 KVVAIYDYTKDKEDELSFQEGAIIYVIKKNDDGWYeGVMNGVTGLFPGNYVESIMH 59

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 1; ASAP1 is also called DDEF1 (Development and Differentiation Enhancing Factor 1), AMAP1, centaurin beta-4, or PAG2. an Arf GTPase activating protein (GAP) with activity towards Arf1 and Arf5 but not Arf6. However, it has been shown to bind GTP-Arf6 stably without GAP activity. It has been implicated in cell growth, migration, and survival, as well as in tumor invasion and malignancy. It binds paxillin and cortactin, two components of invadopodia which are essential for tumor invasiveness. It also binds focal adhesion kinase (FAK) and the SH2/SH3 adaptor CrkL. ASAP1 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212898 [Multi-domain] Cd Length: 57 Bit Score: 35.75 E-value: 7.42e-03

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                  ....*....|....*....|....*....|....*....|....*...
gi 1370477838 143 AKKDNHLNFSKHDIITVL-EQQENWWFGEVHG---GRGWFPKSYVKII 186
Cdd:cd11965    10 ADNDDELTFVEGEVIIVTgEEDQEWWIGHIEGqpeRKGVFPVSFVHIL 57

Src Homology 3 domain of Brain-specific Angiogenesis Inhibitor 1-Associated Protein 2-Like 1, also called Insulin Receptor Tyrosine Kinase Substrate (IRTKS); BAIAP2L1 or IRTKS is widely expressed, serves as a substrate for the insulin receptor, and binds the small GTPase Rac. It plays a role in regulating the actin cytoskeleton and colocalizes with F-actin, cortactin, VASP, and vinculin. BAIAP2L1 expression leads to the formation of short actin bundles, distinct from filopodia-like protrusions induced by the expression of the related protein IRSp53. IRTKS mediates the recruitment of effector proteins Tir and EspFu, which regulate host cell actin reorganization, to bacterial attachment sites. It contains an N-terminal IMD or Inverse-Bin/Amphiphysin/Rvs (I-BAR) domain, an SH3 domain, and a WASP homology 2 (WH2) actin-binding motif at the C-terminus. The SH3 domain of IRTKS has been shown to bind the proline-rich C-terminus of EspFu. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212846 Cd Length: 58 Bit Score: 35.66 E-value: 7.58e-03

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                  ....*....|....*....|....*....|....*....|....*..
gi 1370477838 371 AANNEDELSFSKGQLINVMNKDDPDWW---QGEINGVTGLFPSNYVK 414
Cdd:cd11913    11 AGNNKTLLSFAQGDVITLLIPEEKDGWlygEHDTTKARGWFPSSYTR 57

C2 domain first repeat present in RasA2 and RasA3; RasA2 and RasA3 are GAP1s (GTPase activating protein 1s ), Ras-specific GAP members, which suppresses Ras function by enhancing the GTPase activity of Ras proteins resulting in the inactive GDP-bound form of Ras. In this way it can control cellular proliferation and differentiation. RasA2 and RasA3 are both inositol 1,3,4,5-tetrakisphosphate-binding proteins and contain an N-terminal C2 domain, a Ras-GAP domain, a pleckstrin-homology (PH) domain which localizes it to the plasma membrane, and Bruton's Tyrosine Kinase (BTK) a zinc binding domain. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 176046 [Multi-domain] Cd Length: 121 Bit Score: 37.42 E-value: 8.02e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKACK-PNGKSNPYCEISMGSQS-YTTRTIQDTLNPKWNFNCQFFIKDLYQDvLCLTLFDRDQFSPDDFL 880
Cdd:cd08401     2 LKIKIGEAKNLPPRSgPNKMRDCYCTVNLDQEEvFRTKTVEKSLCPFFGEDFYFEIPRTFRH-LSFYIYDRDVLRRDSVI 80


                  ....*
gi 1370477838 881 GRTEI 885
Cdd:cd08401    81 GKVAI 85

Second Src Homology 3 domain of SH3 domain containing ring finger protein 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the second SH3 domain, located C-terminal of the first SH3 domain at the N-terminal half, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212863 Cd Length: 55 Bit Score: 35.35 E-value: 8.53e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1370477838 363 QVIAMYDYAANNE----DELSFSKGQLINVMNKDDPDWWQGEINGVTGLFPSNYV 413
Cdd:cd11930     1 QCKALYDFEVKDKeadkDCLPFAKDDILTVIRRVDENWAEGMLGDKIGIFPISYV 55

Second Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212835 [Multi-domain] Cd Length: 55 Bit Score: 35.36 E-value: 9.43e-03

                          10
                  ....*....|....*....
gi 1370477838  27 GWLYGSFQGNFGWFPCNYV 45
Cdd:cd11902    34 GWWRGSYNGQIGWFPSNYV 52

C2 domain first repeat present in RasA1 and RasA4; Rasal1 and RasA4 are both members of GAP1 (GTPase activating protein 1). Rasal1 responds to repetitive Ca2+ signals by associating with the plasma membrane and deactivating Ras. RasA4 suppresses Ras function by enhancing the GTPase activity of Ras proteins resulting in the inactive GDP-bound form of Ras. In this way it can control cellular proliferation and differentiation. Both of these proteins contains two C2 domains, a Ras-GAP domain, a plextrin homology (PH)-like domain, and a Bruton's Tyrosine Kinase (BTK) zinc binding domain. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

Pssm-ID: 176018 [Multi-domain] Cd Length: 121 Bit Score: 37.11 E-value: 9.47e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370477838 803 LMVHVIEATELKACKPNGKSNPYCEISMGSQSYT-TRTIQDTLNPKWNFNCQFFIKdLYQDVLCLTLFDRDQFSPDDFLG 881
Cdd:cd04054     2 LYIRIVEGKNLPAKDITGSSDPYCIVKVDNEVIIrTATVWKTLNPFWGEEYTVHLP-PGFHTVSFYVLDEDTLSRDDVIG 80


                  ....
gi 1370477838 882 RTEI 885
Cdd:cd04054    81 KVSL 84

Src homology 3 domain of Abl Interactor 2; Abi2 is highly expressed in the brain and eye. It regulates actin cytoskeletal reorganization at adherens junctions and dendritic spines, which is important in cell morphogenesis, migration, and cognitive function. Mice deficient with Abi2 show defects in orientation and migration of lens fibers, neuronal migration, dendritic spine morphology, as well as deficits in learning and memory. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212905 [Multi-domain] Cd Length: 61 Bit Score: 35.37 E-value: 9.50e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1370477838 296 YVASGSEQLSLAPGQLILILKKNTSGWWQGELQArgkkrQKGWFPASHVK-LLGPS 350
Cdd:cd11972    11 YTKDKEDELSFQEGAIIYVIKKNDDGWYEGVMNG-----VTGLFPGNYVEsIMHYS 61