protein kinase C conserved region 1 (C1 domain) found in SH3 and cysteine-rich domain-containing protein 3 (Stac3) and similar proteins; Stac3 is an essential component of the skeletal muscle excitation-contraction coupling (ECC) machinery. It is required for normal excitation-contraction coupling in skeletal muscle and for normal muscle contraction in response to membrane depolarization. It plays an essential role for normal Ca2+ release from the sarcplasmic reticulum, which ultimately leads to muscle contraction. Stac3 contains a cysteine-rich C1 domain and two SH3 domains at the C-terminus. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 767973708  85 VNDKPHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYVEMQRCFGK 143
Cdd:cd20882    1 VNDKPHKFKDHYFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHHHCQSYVEFQRCFGK 59

Second C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing proteins 1 and 3; This model represents the second C-terminal SH3 domain of Stac1 and 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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 767973708 310 VHRVTRSFVGNREIGQITLKKDQIVVQKGDEAGGYVKVYTGRKVGLFPTDF 360
Cdd:cd11834    1 VHRVTRSFVGNKEIGQITLKKDQIVVQKGEEQNGYIKVYTGRKVGLFPLDF 51

protein kinase C conserved region 1 (C1 domain) found in SH3 and cysteine-rich domain-containing protein 3 (Stac3) and similar proteins; Stac3 is an essential component of the skeletal muscle excitation-contraction coupling (ECC) machinery. It is required for normal excitation-contraction coupling in skeletal muscle and for normal muscle contraction in response to membrane depolarization. It plays an essential role for normal Ca2+ release from the sarcplasmic reticulum, which ultimately leads to muscle contraction. Stac3 contains a cysteine-rich C1 domain and two SH3 domains at the C-terminus. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 767973708  85 VNDKPHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYVEMQRCFGK 143
Cdd:cd20882    1 VNDKPHKFKDHYFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHHHCQSYVEFQRCFGK 59

Second C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing proteins 1 and 3; This model represents the second C-terminal SH3 domain of Stac1 and 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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 767973708 310 VHRVTRSFVGNREIGQITLKKDQIVVQKGDEAGGYVKVYTGRKVGLFPTDF 360
Cdd:cd11834    1 VHRVTRSFVGNKEIGQITLKKDQIVVQKGEEQNGYIKVYTGRKVGLFPLDF 51

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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 767973708  253 VALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGK-IGEKVGFFP 297
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVLEKSEDGWWKGRnKGGKEGLIP 46

Protein kinase C conserved region 1 (C1) domains (Cysteine-rich domains); Some bind phorbol esters and diacylglycerol. Some bind RasGTP. Zinc-binding domains.

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....
gi 767973708    90 HKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQS 133
Cdd:smart00109   1 HKHVFRTFTKPTFCCVCRKSIWGSFKQGLRCSECKVKCHKKCAD 44

Unstructured on SH3 and cysteine-rich domain-containing protein 2; STAC2_u1 is a region of natively unstructured but highly conserved sequence between C1_1 pfam00130, and an SH3 domain, eg pfam00018, on SH3 and cysteine-rich domain-containing proteins from higher eukaryotes. The function is not known.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767973708  147 GFHRAYSSPLYSNQQYACVKDLSAA---NRNDPVFETLRTGVIMANKERKKGQADKKNPVAAMMEEEPE------SARPE 217
Cdd:pfam16664   2 AFRRNFSSPLLIEDQLGVVKEVPPAagnKKVDPVYEALRYGTSLAQMSRSSFGSSSESPTRSLHESREEledkqsSPSAE 81

                          90       100
                  ....*....|....*....|....*....
gi 767973708  218 EGKPQD---GNPEGDKKAEKKTPDDKHKQ 243
Cdd:pfam16664  82 EEKIDDvvfVESEDPEESEKKAEELKSQQ 110

protein kinase C conserved region 1 (C1 domain) found in SH3 and cysteine-rich domain-containing protein 3 (Stac3) and similar proteins; Stac3 is an essential component of the skeletal muscle excitation-contraction coupling (ECC) machinery. It is required for normal excitation-contraction coupling in skeletal muscle and for normal muscle contraction in response to membrane depolarization. It plays an essential role for normal Ca2+ release from the sarcplasmic reticulum, which ultimately leads to muscle contraction. Stac3 contains a cysteine-rich C1 domain and two SH3 domains at the C-terminus. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 767973708  85 VNDKPHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYVEMQRCFGK 143
Cdd:cd20882    1 VNDKPHKFKDHYFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHHHCQSYVEFQRCFGK 59

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 767973708 251 YFVALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFIIR 303
Cdd:cd11833    1 TYVALYKFKPQENEDLEMRPGDKITLLDDSNEDWWKGKIEDRVGFFPANFVQR 53

protein kinase C conserved region 1 (C1 domain) found in the SH3 and cysteine-rich domain-containing protein (Stac) family; Stac proteins are putative adaptor proteins that are important for neuronal function. 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. Stac proteins contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 767973708  90 HKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYVEM 137
Cdd:cd20817    1 HSFQEHTFKKPTFCDVCKELLVGLSKQGLRCKNCKMNVHHKCQEGVPD 48

protein kinase C conserved region 1 (C1 domain) found in SH3 and cysteine-rich domain-containing protein (Stac1) and similar proteins; Stac1, also called Src homology 3 and cysteine-rich domain-containing protein, promotes expression of the ion channel CACNA1H at the cell membrane, and thereby contributes to the regulation of channel activity. It plays a minor and redundant role in promoting the expression of calcium channel CACNA1S at the cell membrane, and thereby contributes to increased channel activity. It slows down the inactivation rate of the calcium channel CACNA1C. Stac1 contains a cysteine-rich C1 domain and two SH3 domains at the C-terminus. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 767973708  88 KPHKFKDHFFKKPKFCDVCARMIV-LNNKFGLRCKNCKTNIHEHCQSYVEMQRCFGK 143
Cdd:cd20880    1 KAHSFQEYIFKKPTFCDVCNHMIVgTNAKHGLRCKACKMSIHHKCTDGIGQQRCMGK 57

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.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*
gi 767973708   248 QSHYFVALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIG-EKVGFFPPNFI 301
Cdd:smart00326   1 EGPQVRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRLGrGKEGLFPSNYV 55

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 767973708 251 YFVALYRFKALEKDDLDFPPGEKITVID--DSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11842    1 KAVALYDFAGEQPGDLAFQKGDIITILKksDSQNDWWTGRIGGREGIFPANYV 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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 767973708 254 ALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11964    5 AIYDFEAAEDNELTFKAGDIITILDDSDPNWWKGETPQGTGLFPSNFV 52

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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 767973708 254 ALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11963    6 ALYDFEAVEDNELTFKHGEIIIVLDDSDANWWKGENHRGVGLFPSNFV 53

second protein kinase C conserved region 1 (C1 domain) found in novel protein kinase C (nPKC) epsilon, eta, and similar proteins; PKCs are classified into three groups (classical, atypical, and novel) depending on their mode of activation and the structural characteristics of their regulatory domain. nPKCs are calcium-independent, but require DAG (1,2-diacylglycerol) and phosphatidylserine (PS) for activity. PKC-epsilon has been shown to behave as an oncoprotein. Its overexpression contributes to neoplastic transformation depending on the cell type. It contributes to oncogenesis by inducing disordered cell growth and inhibiting cell death. It also plays a role in tumor invasion and metastasis. PKC-epsilon has also been found to confer cardioprotection against ischemia and reperfusion-mediated damage. Other cellular functions include the regulation of gene expression, cell adhesion, and cell motility. PKC-eta is predominantly expressed in squamous epithelia, where it plays a crucial role in the signaling of cell-type specific differentiation. It is also expressed in pro-B cells and early-stage thymocytes, and acts as a key regulator in early B-cell development. PKC-eta increases glioblastoma multiforme (GBM) proliferation and resistance to radiation, and is being developed as a therapeutic target for the management of GBM. Members of this family contain two copies of C1 domain. This model corresponds to the second one. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 767973708  89 PHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYV 135
Cdd:cd20838    2 PHRFSVHNYKRPTFCDHCGSLLYGLYKQGLQCKVCKMNVHKRCQKNV 48

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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 767973708 254 ALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11950    4 ALYDFEALEDDELGFNSGDVIEVLDSSNPSWWKGRLHGKLGLFPANYV 51

second protein kinase C conserved region 1 (C1 domain) found in classical (or conventional) protein kinase C (cPKC), novel protein kinase C (nPKC), and similar proteins; PKCs are classified into three groups (classical, atypical, and novel) depending on their mode of activation and the structural characteristics of their regulatory domain. PKCs undergo three phosphorylations in order to take mature forms. In addition, cPKCs depend on calcium, DAG (1,2-diacylglycerol), and in most cases, phosphatidylserine (PS) for activation. nPKCs are calcium-independent, but require DAG and PS for activity, while atypical PKCs (aPKCs) only require PS. PKCs phosphorylate and modify the activities of a wide variety of cellular proteins including receptors, enzymes, cytoskeletal proteins, transcription factors, and other kinases. They play a central role in signal transduction pathways that regulate cell migration and polarity, proliferation, differentiation, and apoptosis. This family includes classical PKCs (cPKCs) and novel PKCs (nPKCs). There are four cPKC isoforms (named alpha, betaI, betaII, and gamma) and four nPKC isoforms (delta, epsilon, eta, and theta). Members of this family contain two copies of C1 domain. This model corresponds to the second one. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 767973708  90 HKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYV 135
Cdd:cd20793    1 HKFKVHTYYSPTFCDHCGSLLYGLVRQGLKCKDCGMNVHHRCKENV 46

Protein kinase C conserved region 1 (C1) domains (Cysteine-rich domains); Some bind phorbol esters and diacylglycerol. Some bind RasGTP. Zinc-binding domains.

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....
gi 767973708    90 HKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQS 133
Cdd:smart00109   1 HKHVFRTFTKPTFCCVCRKSIWGSFKQGLRCSECKVKCHKKCAD 44

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 767973708 254 ALYRFKALEKDDLDFPPGEKITVID--DSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11841    4 ALYSFEGQQPCDLSFQAGDRITVLTrtDSQFDWWEGRLRGRVGIFPANYV 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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 767973708 253 VALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11959    3 VALYDYQAADDDEISFDPDDIITNIEMIDEGWWRGVCRGKYGLFPANYV 51

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 767973708 253 VALYRFKALEKDDLDFPPGEKITVIDDSNEEWW--RGKIGEkVGFFPPNFI 301
Cdd:cd11768    3 VALYDFQPIEPGDLPLEKGEEYVVLDDSNEHWWraRDKNGN-EGYIPSNYV 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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 767973708 251 YFVALYRFKALEKDDLDFPPGEKITVIDDSNEeWWRGKIGEKVGFFPPNFI 301
Cdd:cd11838    1 EYIALYPYESNEPGDLTFNAGDVILVTKKDGE-WWTGTIGDRTGIFPSNYV 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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 767973708 252 FVALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFII 302
Cdd:cd11772    2 FRALYDYEAQHPDELSFEEGDLLYISDKSDPNWWKATCGGKTGLIPSNYVE 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.

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                 ....*....|....*....|....*....|....*....|....*....|
gi 767973708 252 FVALYRFKALEKDDLDFPPGEKITVIDDSNEeWWRGKIGEKVGFFPPNFI 301
Cdd:cd11991    2 YVAMYTYESNEQGDLTFQQGDVILVTKKDGD-WWTGTVGDKTGVFPSNYV 50

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.

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                 ....*....|....*....|....*....|....*....|....*....|.
gi 767973708 252 FVALYRFKALEKDDLDFPPGEKITVIDDSNEEWW--RGKIGEKVGFFPPNF 300
Cdd:cd11845    2 YVALYDYEARTDDDLSFKKGDRLQILDDSDGDWWlaRHLSTGKEGYIPSNY 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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 767973708 251 YFVALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd12046    1 QVVALFSYEASQPEDLEFQKGDVILVLSKVNEDWLEGQCKGKIGIFPSAFV 51

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.

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                 ....*....|....*....|....*....|....*....|....*....
gi 767973708 253 VALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11996    4 IAMYDYTANNEDELSFSKGQLINVLNKDDPDWWQGEINGVTGLFPSNYV 52

second protein kinase C conserved region 1 (C1 domain) found in Caenorhabditis elegans serine/threonine-protein kinase DKF-1 and similar proteins; DKF-1 converts transient diacylglycerol (DAG) signals into prolonged physiological effects, independently of PKC. It plays a role in the regulation of growth and neuromuscular control of movement. It is involved in immune response to Staphylococcus aureus bacterium by activating transcription factor hlh-30 downstream of phospholipase plc-1. Members of this group contain two copies of the C1 domain. This model corresponds to the second one. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

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                 ....*....|....*....|....*....|....*....|....*....
gi 767973708  89 PHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYVEM 137
Cdd:cd20798    1 PHTLAEHNYKKPTVCKVCDKLLVGLVRQGLKCRDCGVNVHKKCASLLPS 49

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.

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gi 767973708 257 RFKALEKDDLDFPPGEKITVID-DSNEE--WWRGKIGEKVGFFP 297
Cdd:cd11835    7 RYTAQAPDELSLEVGDIVSVIDmPPPEEstWWRGKKGFQVGFFP 50

protein kinase C conserved region 1 (C1 domain) found in the myotubularin-related protein Sbf and similar proteins; This group includes Drosophila melanogaster SET domain binding factor (Sbf), the single homolog of human MTMR5/MTMR13, and similar proteins, that show high sequence similarity to vertebrate myotubularin-related proteins (MTMRs) which may function as guanine nucleotide exchange factors (GEFs). Sbf is a pseudophosphatase that coordinates both phosphatidylinositol 3-phosphate (PI(3)P) turnover and Rab21 GTPase activation in an endosomal pathway that controls macrophage remodeling. It also functions as a GEF that promotes Rab21 GTPase activation associated with PI(3)P endosomes. Vertebrate MTMR5 and MTMR13 contain an N-terminal DENN domain, a PH-GRAM domain, an inactive PTP domain, a SET interaction domain, a coiled-coil domain, and a C-terminal PH domain. Members of this family contain these domains and have an additional C1 domain. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

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                 ....*....|....*....|....*....|....*....|....*..
gi 767973708  89 PHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYV 135
Cdd:cd20827    1 PHRFEKHNFTTPTYCDYCSSLLWGLVKTGMRCADCGYSCHEKCLEHV 47

protein kinase C conserved region 1 (C1 domain) found in tensin-2 like (TNS2-like) proteins; The TNS2-like group includes TNS2, and variants of TNS1 and TNS3. Tensin-2 (TNS2), also called C1 domain-containing phosphatase and tensin (C1-TEN), or tensin-like C1 domain-containing phosphatase (TENC1), is an essential component for the maintenance of glomerular basement membrane (GBM) structures. It regulates cell motility and proliferation. It may have phosphatase activity. TNS2 reduces AKT1 phosphorylation, lowers AKT1 kinase activity and interferes with AKT1 signaling. Tensin-1 (TNS1) plays a role in fibrillar adhesion formation. It may be involved in cell migration, cartilage development and in linking signal transduction pathways to the cytoskeleton. Tensin-3 (TNS3), also called tensin-like SH2 domain-containing protein 1 (TENS1), or tumor endothelial marker 6 (TEM6), may play a role in actin remodeling. It is involved in the dissociation of the integrin-tensin-actin complex. Typical TNS1 and TNS3 do not contain C1 domains, but some isoforms/variants do. Members of this family contain an N-terminal region with a zinc finger (C1 domain), a protein tyrosine phosphatase (PTP)-like domain and a protein kinase 2 (C2) domain, and a C-terminal region with SH2 and pTyr binding (PTB) domains. This model corresponds to C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

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gi 767973708  88 KPHKFKDHFFKKPKFCDVCARMIvlnNKFGLRCKNCKTNIHEHCQSYV 135
Cdd:cd20826    1 KSHSFKEKSFRKPRTCDVCKQII---WNEGSSCRVCKYACHRKCEPKV 45

protein kinase C conserved region 1 (C1 domain) found in RAS guanyl-releasing protein 4 (RASGRP4) and similar proteins; RASGRP4 functions as a cation- and diacylglycerol (DAG)-regulated nucleotide exchange factor activating Ras through the exchange of bound GDP for GTP. It may function in mast cell differentiation. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

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                 ....*....|....*....|....*....|....*....|....*....|
gi 767973708  89 PHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYVEMQ 138
Cdd:cd20863    3 LHNFHETTFKKPTFCDSCSGFLWGVTKQGYRCQDCGINCHKHCKDQVDVE 52

first protein kinase C conserved region 1 (C1 domain) found in type I diacylglycerol kinases; Diacylglycerol (DAG) kinase (EC 2.7.1.107) is a lipid kinase that phosphorylates diacylglycerol to form phosphatidic acid. Type I DAG kinases (DGKs) contain EF-hand structures that bind Ca(2+) and recoverin homology domains, in addition to C1 and catalytic domains that are present in all DGKs. Type I DGKs, regulated by calcium binding, include three DGK isozymes (alpha, beta and gamma). DAG kinase alpha, also called 80 kDa DAG kinase, or diglyceride kinase alpha (DGK-alpha), is active upon cell stimulation, initiating the resynthesis of phosphatidylinositols and attenuating protein kinase C activity. DAG kinase beta, also called 90 kDa DAG kinase, or diglyceride kinase beta (DGK-beta), exhibits high phosphorylation activity for long-chain diacylglycerols. DAG kinase gamma, also called diglyceride kinase gamma (DGK-gamma), reverses the normal flow of glycerolipid biosynthesis by phosphorylating diacylglycerol back to phosphatidic acid. Members of this family contain two copies of the C1 domain. This model corresponds to the first one. DGK-alpha contains atypical C1 domains, while DGK-beta and DGK-gamma contain typical C1 domains that bind DAG and phorbol esters. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 767973708  87 DKPHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEhcqsyvemqRCFGKIPPGFHRAYSS 154
Cdd:cd20799    3 DGQHVWRLKHFNKPAYCNVCENMLVGLRKQGLCCTFCKYTVHE---------RCVSRAPASCIRTYVK 61

second protein kinase C conserved region 1 (C1 domain) found in the classical (or conventional) protein kinase C (cPKC) family; PKCs are classified into three groups (classical, atypical, and novel) depending on their mode of activation and the structural characteristics of their regulatory domain. cPKCs are potent kinases for histones, myelin basic protein, and protamine. They depend on calcium, DAG (1,2-diacylglycerol), and in most cases, phosphatidylserine (PS) for activation. There are four cPKC isoforms, named alpha, betaI, betaII, and gamma. PKC-alpha is expressed in many tissues and is associated with cell proliferation, apoptosis, and cell motility. It plays a role in the signaling of the growth factors PDGF, VEGF, EGF, and FGF. Abnormal levels of PKC-alpha have been detected in many transformed cell lines and several human tumors. In addition, PKC-alpha is required for HER2 dependent breast cancer invasion. The PKC beta isoforms (I and II), generated by alternative splicing of a single gene, are preferentially activated by hyperglycemia-induced DAG (1,2-diacylglycerol) in retinal tissues. This is implicated in diabetic microangiopathy such as ischemia, neovascularization, and abnormal vasodilator function. PKC-beta also plays an important role in VEGF signaling. In addition, glucose regulates proliferation in retinal endothelial cells via PKC-betaI. PKC-beta is also being explored as a therapeutic target in cancer. It contributes to tumor formation and is involved in the tumor host mechanisms of inflammation and angiogenesis. PKC-gamma is mainly expressed in neuronal tissues. It plays a role in protection from ischemia. Members of this family contain two copies of C1 domain. This model corresponds to the second one. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

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gi 767973708  90 HKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYV 135
Cdd:cd20836    1 HKFKVHTYSSPTFCDHCGSLLYGLIHQGMKCDTCDMNVHKRCVKNV 46

first protein kinase C conserved region 1 (C1 domain) found in Caenorhabditis elegans serine/threonine-protein kinase DKF-1 and similar proteins; DKF-1 converts transient diacylglycerol (DAG) signals into prolonged physiological effects, independently of PKC. It plays a role in the regulation of growth and neuromuscular control of movement. It is involved in immune response to Staphylococcus aureus bacterium by activating transcription factor hlh-30 downstream of phospholipase plc-1. Members of this group contain two copies of the C1 domain. This model corresponds to the first one. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

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                 ....*....|....*....|....*....|....*....|....*
gi 767973708  87 DKPHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHC 131
Cdd:cd20797    1 TRPHVVEVEQYMTPTFCDYCGEMLTGLMKQGVKCKNCRCNFHKRC 45

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.

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                 ....*....|....*....|....*....|....*....|....*....|....
gi 767973708 253 VALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKI-----GEKVGFFPPNFI 301
Cdd:cd11887    5 KALYPYESDHEDDLNFDVGQLITVTEEEDADWYFGEYvdsngNTKEGIFPKNFV 58

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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 767973708 254 ALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11827    4 ALYAYDAQDTDELSFNEGDIIEILKEDPSGWWTGRLRGKEGLFPGNYV 51

second protein kinase C conserved region 1 (C1 domain) found in the family of protein kinase D (PKD); PKDs are important regulators of many intracellular signaling pathways such as ERK and JNK, and cellular processes including the organization of the trans-Golgi network, membrane trafficking, cell proliferation, migration, and apoptosis. They are activated in a PKC-dependent manner by many agents including diacylglycerol (DAG), PDGF, neuropeptides, oxidative stress, and tumor-promoting phorbol esters, among others. Mammals harbor three types of PKDs: PKD1 (or PKCmu), PKD2, and PKD3 (or PKCnu). PKDs contain N-terminal tandem cysteine-rich zinc binding C1 (PKC conserved region 1), central PH (Pleckstrin Homology), and C-terminal catalytic kinase domains. This model corresponds to the second C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

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                 ....*....|....*....|....*....|....*....|....*..
gi 767973708  89 PHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYV 135
Cdd:cd20796    1 PHTFVVHTYTKPTVCQHCKKLLKGLFRQGLQCKDCKFNCHKKCAEKV 47

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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 767973708 254 ALYRFKALEKDDLDFPPGEKITVIDDSNEEWWR-GKIGEKVGFFPPNFI 301
Cdd:cd11849    4 ALYDFKSAEPNTLSFSEGETFLLLERSNAHWWLvTNHSGETGYVPANYV 52

protein kinase C conserved region 1 (C1 domain) found in the RAS guanyl-releasing protein (RASGRP) family; The RASGRP family includes RASGRP1-4. They function as cation-, usually calcium-, and diacylglycerol (DAG)-regulated nucleotide exchange factor activating Ras through the exchange of bound GDP for GTP. RASGRP1, also called calcium and DAG-regulated guanine nucleotide exchange factor II (CalDAG-GEFII) or Ras guanyl-releasing protein, activates the Erk/MAP kinase cascade and regulates T-cell/B-cell development, homeostasis and differentiation by coupling T-lymphocyte/B-lymphocyte antigen receptors to Ras. RASGRP1 also regulates NK cell cytotoxicity and ITAM-dependent cytokine production by activation of Ras-mediated ERK and JNK pathways. RASGRP2, also called calcium and DAG-regulated guanine nucleotide exchange factor I (CalDAG-GEFI), Cdc25-like protein (CDC25L), or F25B3.3 kinase-like protein, specifically activates Rap and may also activate other GTPases such as RRAS, RRAS2, NRAS, KRAS but not HRAS. RASGRP2 is involved in aggregation of platelets and adhesion of T-lymphocytes and neutrophils probably through inside-out integrin activation, as well as in the muscarinic acetylcholine receptor M1/CHRM1 signaling pathway. RASGRP3, also called calcium and DAG-regulated guanine nucleotide exchange factor III (CalDAG-GEFIII), or guanine nucleotide exchange factor for Rap1, is a guanine nucleotide-exchange factor activating H-Ras, R-Ras and Ras-associated protein-1/2. It functions as an important mediator of signaling downstream from receptor coupled phosphoinositide turnover in B and T cells. RASGRP4 may function in mast cell differentiation. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

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                 ....*....|....*....|....*....|....*....|....*....|
gi 767973708  89 PHKFKDHFFKKPKFCDVCARMIVLNNKFGLRCKNCKTNIHEHCQSYVEMQ 138
Cdd:cd20808    1 KHNFQETTYFKPTFCDHCTGLLWGLIKQGYKCKDCGINCHKHCKDLVVVE 50

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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 767973708 253 VALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11995    4 IGMYDYTAQNDDELAFSKGQIINVLNKEDPDWWKGELNGQVGLFPSNYV 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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 767973708 251 YFVALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNFI 301
Cdd:cd11974    2 YAEALWDHVTMDDQELAFKAGDVIRVLEASNKDWWWGRNEDREAWFPASFV 52

protein kinase C conserved region 1 (C1 domain) found in the 190 kDa guanine nucleotide exchange factor (p190RhoGEF)-like family; The p190RhoGEF-like protein family includes p190RhoGEF, Rho guanine nucleotide exchange factor 2 (ARHGEF2), A-kinase anchor protein 13 (AKAP-13) and similar proteins. p190RhoGEF is a brain-enriched, RhoA-specific guanine nucleotide exchange factor that regulates signaling pathways downstream of integrins and growth factor receptors. It is involved in axonal branching, synapse formation and dendritic morphogenesis, as well as in focal adhesion formation, cell motility and B-lymphocytes activation. ARHGEF2 acts as a guanine nucleotide exchange factor (GEF) that activates Rho-GTPases by promoting the exchange of GDP for GTP. It is thought to play a role in actin cytoskeleton reorganization in different tissues since its activation induces formation of actin stress fibers. AKAP-13 is a scaffold protein that plays an important role in assembling signaling complexes downstream of several types of G protein-coupled receptors. It activates RhoA in response to signaling via G protein-coupled receptors via its function as Rho guanine nucleotide exchange factor. It may also activate other Rho family members. AKAP-13 plays a role in cell growth, cell development and actin fiber formation. Members of this family share a common domain architecture containing C1, RhoGEF or Dbl-homologous (DH), and Pleckstrin Homology (PH) domains. Some members may contain additional domains such as the DUF5401 domain. This model describes the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

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gi 767973708 103 CDVCARmiVLNNKFGLRCKNCKTNIHEH-CQSYVE 136
Cdd:cd20815   17 CDVCSK--PLTNKPALQCENCSVNVHDSsCKDQLA 49

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.

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gi 767973708 251 YFVALYRFKALEKDDLDFPPGEKITVIDDSNEEWWRGKIGEKVGFFPPNF 300
Cdd:cd11797    1 YGVALYRFQALEPNELDFEVGDRIRIIATLEDGWLEGELKGRRGIFPHRF 50

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.

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gi 767973708 251 YFVALYRFKALEKDDLDFPPGEKITVIDDSNEE--WWRGKIGEKVGFFPPNFI 301
Cdd:cd11836    1 KYRALYAFEARNPDEISFQPGDIIQVDESQVAEpgWLAGELKGKTGWFPANYV 53