Ca2+-binding protein, EF-hand superfamily [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  20 IKRLGRRFKKLDLDKSGSLSVEEFMSLPElrhnPLVRRVIDVFDTDGDGEVDFKEFILGTSQfSVKGDEEQKLRFAFSIY 99
Cdd:COG5126     4 RRKLDRRFDLLDADGDGVLERDDFEALFR----RLWATLFSEADTDGDGRISREEFVAGMES-LFEATVEPFARAAFDLL 78

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010 100 DMDKDGYISNGELFQVLKMMvgnNLTDWQLQQLVDKtiiiLDKDGDGKISFEEFSAVVRD 159
Cdd:COG5126    79 DTDGDGKISADEFRRLLTAL---GVSEEEADELFAR----LDTDGDGKISFEEFVAAVRD 131

Ca2+-binding protein, EF-hand superfamily [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  20 IKRLGRRFKKLDLDKSGSLSVEEFMSLPElrhnPLVRRVIDVFDTDGDGEVDFKEFILGTSQfSVKGDEEQKLRFAFSIY 99
Cdd:COG5126     4 RRKLDRRFDLLDADGDGVLERDDFEALFR----RLWATLFSEADTDGDGRISREEFVAGMES-LFEATVEPFARAAFDLL 78

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010 100 DMDKDGYISNGELFQVLKMMvgnNLTDWQLQQLVDKtiiiLDKDGDGKISFEEFSAVVRD 159
Cdd:COG5126    79 DTDGDGKISADEFRRLLTAL---GVSEEEADELFAR----LDTDGDGKISFEEFVAAVRD 131

EF-hand, calcium binding motif; A diverse superfamily of calcium sensors and calcium signal modulators; most examples in this alignment model have 2 active canonical EF hands. Ca2+ binding induces a conformational change in the EF-hand motif, leading to the activation or inactivation of target proteins. EF-hands tend to occur in pairs or higher copy numbers.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1493556010  91 KLRFAFSIYDMDKDGYISNGELFQVLKMMVGNnltdwQLQQLVDKTIIILDKDGDGKISFEEFSAVVR 158
Cdd:cd00051     1 ELREAFRLFDKDGDGTISADELKAALKSLGEG-----LSEEEIDEMIREVDKDGDGKIDFEEFLELMA 63

XopAW family type III secretion system calcium-binding effector;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  25 RRFKKLDLDKSGSLSVEEFMSLpeLRHNPLVRRVIDV------FDTDGDGEVDFKEFILGT------SQFSVKGDEEQKL 92
Cdd:NF041410   31 QLFAKLDSDGDGSVSQDELSSA--LSSKSDDGSLIDLselfsdLDSDGDGSLSSDELAAAAppppppPDQAPSTELADDL 108

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1493556010  93 rfaFSIYDMDKDGYISNGELfQVLKMMVGNNLtdwQLQQLVDKtiiiLDKDGDGKISFEEFSA 155
Cdd:NF041410  109 ---LSALDTDGDGSISSDEL-SAGLTSAGSSA---DSSQLFSA----LDSDGDGSVSSDELAA 160

Ca2+-binding protein, EF-hand superfamily [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  20 IKRLGRRFKKLDLDKSGSLSVEEFMSLPElrhnPLVRRVIDVFDTDGDGEVDFKEFILGTSQfSVKGDEEQKLRFAFSIY 99
Cdd:COG5126     4 RRKLDRRFDLLDADGDGVLERDDFEALFR----RLWATLFSEADTDGDGRISREEFVAGMES-LFEATVEPFARAAFDLL 78

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010 100 DMDKDGYISNGELFQVLKMMvgnNLTDWQLQQLVDKtiiiLDKDGDGKISFEEFSAVVRD 159
Cdd:COG5126    79 DTDGDGKISADEFRRLLTAL---GVSEEEADELFAR----LDTDGDGKISFEEFVAAVRD 131

calmodulin; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  11 MCSHFDNDEIKRLGRRFKKLDLDKSGSLSVEEF-MSLPELRHNPL---VRRVIDVFDTDGDGEVDFKEFILGTSQFSVKG 86
Cdd:PTZ00184    1 MADQLTEEQIAEFKEAFSLFDKDGDGTITTKELgTVMRSLGQNPTeaeLQDMINEVDADGNGTIDFPEFLTLMARKMKDT 80

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1493556010  87 DEEQKLRFAFSIYDMDKDGYISNGELFQVLKMMvGNNLTDwqlqQLVDKTIIILDKDGDGKISFEEF 153
Cdd:PTZ00184   81 DSEEEIKEAFKVFDRDGNGFISAAELRHVMTNL-GEKLTD----EEVDEMIREADVDGDGQINYEEF 142

Penta-EF hand, calcium binding motifs, found in Group I PEF proteins; The family corresponds to Group I PEF proteins that have been found not only in higher animals but also in lower animals, plants, fungi and protists. Group I PEF proteins include apoptosis-linked gene 2 protein (ALG-2), peflin and similar proteins. ALG-2, also termed programmed cell death protein 6 (PDCD6), is a widely expressed calcium-binding modulator protein associated with cell proliferation and death, as well as cell survival. It forms a homodimer in the cell or a heterodimer with its closest paralog peflin. Among the PEF proteins, ALG-2 can bind three Ca2+ ions through its EF1, EF3, and EF5 hands, where it is unique in that its EF5 hand binds Ca2+ ion in a canonical coordination. Peflin is a ubiquitously expressed 30-kD PEF protein containing five EF-hand motifs in its C-terminal domain and a longer N-terminal hydrophobic domain (NHB domain) than any other member of the PEF family. The NHB domain harbors nine repeats of a nonapeptide (A/PPGGPYGGP). Peflin may modulate the function of ALG-2 in Ca2+ signaling. It exists only as a heterodimer with ALG-2, and binds two Ca2+ ions through its EF1 and EF3 hands. Its additional EF5 hand is unpaired and does not bind Ca2+ ion but mediates the heterodimerization with ALG-2. The dissociation of heterodimer occurs in the presence of Ca2+.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  22 RLGRRFKKLDLDKSGSLSVEEF-MSLPELRHNPL----VRRVIDVFDTDGDGEVDFKEFilgtsqfsvKG--DEEQKLRF 94
Cdd:cd16180     1 ELRRIFQAVDRDRSGRISAKELqRALSNGDWTPFsietVRLMINMFDRDRSGTINFDEF---------VGlwKYIQDWRR 71

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1493556010  95 AFSIYDMDKDGYISNGELFQVLKMMvGNNLTDWQLQQLVDKtiiiLDKDGDGKISFEEF 153
Cdd:cd16180    72 LFRRFDRDRSGSIDFNELQNALSSF-GYRLSPQFVQLLVRK----FDRRRRGSISFDDF 125

EF-hand, calcium binding motif, found in CREC-EF hand family; The CREC (Cab45/reticulocalbin/ERC45/calumenin)-EF hand family contains a group of six EF-hand, low-affinity Ca2+-binding proteins, including reticulocalbin (RCN-1), ER Ca2+-binding protein of 55 kDa (ERC-55, also known as TCBP-49 or E6BP), reticulocalbin-3 (RCN-3), Ca2+-binding protein of 45 kDa (Cab45 and its splice variant Cab45b), and calumenin ( also known as crocalbin or CBP-50). The proteins are not only localized in various parts of the secretory pathway, but also found in the cytosolic compartment and at the cell surface. They interact with different ligands or proteins and have been implicated in the secretory process, chaperone activity, signal transduction as well as in a large variety of disease processes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  22 RLGRRFKKLDLDKSGSLSVEEFMSLPELRHNPLVRRVI-----DVFDTDGDGEVDFKEFIlGTSQFSVKGDEEQ------ 90
Cdd:cd15899   124 KDKKRFEAADQDGDLILTLEEFLAFLHPEESPYMLDFViketlEDLDKNGDGFISLEEFI-SDPYSADENEEEPewvkve 202

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1493556010  91 KLRFAfSIYDMDKDGYISNGELfqvLKMMVGNNltDWQLQQLVDKTIIILDKDGDGKISFEE 152
Cdd:cd15899   203 KERFV-ELRDKDKDGKLDGEEL---LSWVDPSN--QEIALEEAKHLIAESDENKDGKLSPEE 258

EF-hand, calcium binding motif, found in reticulocalbin-2 (RCN2) mainly from protostomes; This family corresponds to a group of uncharacterized RCN2-like proteins, which are mainly found in protostomes. Although their biological function remains unclear, they show high sequence similarity with RCN2 (also known as E6BP or TCBP-49), which is an endoplasmic reticulum resident low-affinity Ca2+-binding protein that has been implicated in immunity, redox homeostasis, cell cycle regulation and coagulation. Members in this family contain six copies of the EF-hand Ca2+-binding motif, but may lack a C-terminal His-Asp-Glu-Leu (HDEL) tetrapeptide that is required for retention of RCN2 in the endoplasmic reticulum (ER).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  26 RFKKLDLDKSGSLSVEEFMSLPELRHNP-----LVRRVIDVFDTDGDGEVDFKEFILGT-SQFSVKGDEEQKLRFAFSiY 99
Cdd:cd16227   127 MFEAADLNKDGKLDKTEFSAFQHPEEYPhmhpvLIEQTLRDKDKDNDGFISFQEFLGDRaGHEDKEWLLVEKDRFDED-Y 205

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1493556010 100 DMDKDGYISNGElfqVLKMMVGNNltDWQLQQLVDKTIIILDKDGDGKISFEE 152
Cdd:cd16227   206 DKDGDGKLDGEE---ILSWLVPDN--EEIAEEEVDHLFASADDDHDDRLSFDE 253

EF-hand, calcium binding motif, found in calumenin, reticulocalbin-1 (RCN-1), reticulocalbin-3 (RCN-3), and similar proteins; The family corresponds to a group of six EF-hand Ca2+-binding proteins, including calumenin (also known as crocalbin or CBP-50), reticulocalbin-1 (RCN-1), reticulocalbin-3 (RCN-3), and similar proteins. Calumenin is an endo/sarcoplasmic reticulum (ER/SR) resident low-affinity Ca2+-binding protein that contains six EF-hand domains and a C-terminal SR retention signal His-Asp-Glu-Phe (HDEF) tetrapeptide. It functions as a novel regulator of SERCA2, and its expressional changes are tightly coupled with Ca2+-cycling of cardiomyocytes. It is also broadly involved in haemostasis and in the pathophysiology of thrombosis. Moreover, the extracellular calumenin acts as a suppressor of cell migration and tumor metastasis. RCN-1 is an endoplasmic reticulum resident Ca2+-binding protein with a carboxyl-terminal His-Asp-Glu-Leu (HDEL) tetrapeptide signal. It acts as a potential negative regulator of B-RAF activation and can negatively modulate cardiomyocyte hypertrophy by inhibition of the mitogen-activated protein kinase signalling cascade. It also plays a key role in the development of doxorubicin-associated resistance. RCN-3 is a putative six EF-hand Ca2+-binding protein that contains five RXXR (X is any amino acid) motifs and a C-terminal ER retrieval signal HDEL tetrapeptide. The RXXR motif represents the target sequence of subtilisin-like proprotein convertases (SPCs). RCN-3 is specifically bound to the paired basic amino-acid-cleaving enzyme-4 (PACE4) precursor protein and plays an important role in the biosynthesis of PACE4.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010   2 GNEASYPAEMCSHFD-NDEIKRLGRRFKKLDLDKSGSLSVEEFM------SLPELRhNPLVRRVIDVFDTDGDGEVDFKE 74
Cdd:cd16226    99 GFLDDEEEDDDLHESyKKMIRRDERRWKAADQDGDGKLTKEEFTaflhpeEFPHMR-DIVVQETLEDIDKNKDGFISLEE 177

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  75 FI--LGTSQFS------VKGDEEQKLRFafsiYDMDKDGYISNGELFQVLkMMVGNNLTDWQLQQLVDKTiiilDKDGDG 146
Cdd:cd16226   178 YIgdMYRDDDEeedpdwVKSEREQFKEF----RDKNKDGKMDREEVKDWI-LPEDYDHAEAEAKHLIYEA----DDDKDG 248

                  ....*.
gi 1493556010 147 KISFEE 152
Cdd:cd16226   249 KLTKEE 254

EF-hand, calcium binding motif, found in homologs of mammalian apoptosis-linked gene 2 protein (ALG-2); The family includes some homologs of mammalian apoptosis-linked gene 2 protein (ALG-2) mainly found in lower eukaryotes, such as a parasitic protist Leishmarua major and a cellular slime mold Dictyostelium discoideum. These homologs contains five EF-hand motifs. Due to the presence of unfavorable residues at the Ca2+-coordinating positions, their non-canonical EF4 and EF5 hands may not bind Ca2+. Two Dictyostelium PEF proteins are the prototypes of this family. They may bind to cytoskeletal proteins and/or signal-transducing proteins localized to detergent-resistant membranes named lipid rafts, and occur as monomers or weak homo- or heterodimers like ALG-2. They can serve as a mediator for Ca2+ signaling-related Dictyostehum programmed cell death (PCD).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  27 FKKLDLDKSGSLSVEEF---MSLPELRHN-PLVRRVIDVFDTDGDGEVDFKEFiLGTSQFSvkgdeeQKLRFAFSIYDMD 102
Cdd:cd16185     6 FRAVDRDRSGSIDVNELqkaLAGGGLLFSlATAEKLIRMFDRDGNGTIDFEEF-AALHQFL------SNMQNGFEQRDTS 78

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1493556010 103 KDGYISNGELFQVLKmMVGNNLTDWQLQQLVDKtiiiLDKDGDGKISFEEF 153
Cdd:cd16185    79 RSGRLDANEVHEALA-ASGFQLDPPAFQALFRK----FDPDRGGSLGFDDY 124

Ca2+-binding protein, EF-hand superfamily [Signal transduction mechanisms];

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1493556010   9 AEMCSHFDNDEIKRLGRRFKKLDLDKSGSLSVEEFMSLPELRH--NPLVRRVIDVFDTDGDGEVDFKEFILGTSQF 82
Cdd:COG5126    57 AGMESLFEATVEPFARAAFDLLDTDGDGKISADEFRRLLTALGvsEEEADELFARLDTDGDGKISFEEFVAAVRDY 132

EF-hand, calcium binding motif, found in uncharacterized calglandulin-like proteins; The family corresponds to a group of uncharacterized calglandulin-like proteins. Although their biological function remain unclear, they show high sequence similarity with human calglandulin-like protein GAGLP, which is an ortholog of calglandulin from the venom glands of Bothrops insularis snake. Both GAGLP and calglandulin are putative Ca2+-binding proteins with four EF-hand motifs. However, members in this family contain only three EF-hand motifs. In this point, they may belong to the parvalbumin-like EF-hand family, which is characterized by the presence of three consecutive EF-hand motifs (helix-loop-helix).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  68 GEVDFKEFILGTSQFSVKGDEEQKLRFAFSIYDMDKDGYISNGELFQVLKMMVGNNLTDWQLQQLVDKTIIILDKDGDGK 147
Cdd:cd16252    15 GSFNYSKFFEYMQKFQTSEQQEEAIRKAFQMLDKDKSGFIEWNEIKYILSTVPSSMPVAPLSDEEAEAMIQAADTDGDGR 94

                          90
                  ....*....|.
gi 1493556010 148 ISFEEFSAVVR 158
Cdd:cd16252    95 IDFQEFSDMVK 105

EF-hand, calcium binding motif, found in parvalbumin-like EF-hand family; The family includes alpha- and beta-parvalbumins, and a group of uncharacterized calglandulin-like proteins. Parvalbumins are small, acidic, cytosolic EF-hand-containing Ca2+-buffer and Ca2+ transporter/shuttle proteins belonging to EF-hand superfamily. They are expressed by vertebrates in fast-twitch muscle cells, specific neurons of the central and peripheral nervous system, sensory cells of the mammalian auditory organ (Corti's cell), and some other cells, and characterized by the presence of three consecutive EF-hand motifs (helix-loop-helix) called AB, CD, and EF, but only CD and EF can chelate metal ions, such as Ca2+ and Mg2+. Thus, they may play an additional role in Mg2+ handling. Moreover, parvalbumins represent one of the major animal allergens. In metal-bound states, parvalbumins possess a rigid and stable tertiary structure and display strong allergenicity. In contrast, the metal-free parvalbumins are intrinsically disordered, and the loss of metal ions results in a conformational change that decreases their IgE binding capacity. Furthermore, parvalbumins have been widely used as a neuronal marker for a variety of functional brain systems. They also function as a Ca2+ shuttle transporting Ca2+ from troponin-C (TnC) to the sarcoplasmic reticulum (SR) Ca2+ pump during muscle relaxation. Thus they may facilitate myocardial relaxation and play important roles in cardiac diastolic dysfunction. Parvalbumins consists of alpha- and beta- sublineages, which can be distinguished on the basis of isoelectric point (pI > 5 for alpha; pI

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  68 GEVDFKEFIlgtSQFSVKGDEEQKLRFAFSIYDMDKDGYISNGELFQVLKMM--VGNNLTDWQLQQLVDKTiiilDKDGD 145
Cdd:cd16251    15 GSFNYKKFF---EHVGLKQKSEDQIKKVFQILDKDKSGFIEEEELKYILKGFsiAGRDLTDEETKALLAAG----DTDGD 87

                          90
                  ....*....|..
gi 1493556010 146 GKISFEEFSAVV 157
Cdd:cd16251    88 GKIGVEEFATLV 99

EF-hand, calcium binding motif, found in alpha-parvalbumin; Alpha-parvalbumin is cytosolic Ca2+/Mg2+-binding protein expressed mainly in fast-twitch skeletal myofibrils, where it may act as a soluble relaxing factor facilitating the Ca2+-mediated relaxation phase. It is also expressed in rapidly firing neurons, particularly GABA-ergic neurons, and thus may confer protection against Ca2+ toxicity. The major role of alpha-parvalbumin is metal buffering and transport of Ca2+. It binds different metal cations, and exhibits very high affinity for Ca2+ and physiologically significant affinity for Mg2+. Alpha-parvalbumin is characterized by the presence of three consecutive EF-hand motifs (helix-loop-helix) called AB, CD, and EF, but only CD and EF can chelate metal ions, such as Ca2+ and Mg2+. Both metal ion-binding sites in alpha-parvalbumin are high-affinity sites. Additionally, in contrast to beta-parvalbumin, alpha-parvalbumin is less acidic and has an additional residue in the C-terminal helix.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1493556010  84 VKGDEEQKLRFAFSIYDMDKDGYISNGELFQVLKMMV--GNNLTDWQLQQLVDKTiiilDKDGDGKISFEEFSAVV 157
Cdd:cd16254    28 LKKKSADDVKKVFHILDKDKSGFIEEDELKFVLKGFSpdGRDLSDKETKALLAAG----DKDGDGKIGIDEFATLV 99

EF-hand, calcium binding motif, found in calumenin, reticulocalbin-1 (RCN-1), reticulocalbin-3 (RCN-3), and similar proteins; The family corresponds to a group of six EF-hand Ca2+-binding proteins, including calumenin (also known as crocalbin or CBP-50), reticulocalbin-1 (RCN-1), reticulocalbin-3 (RCN-3), and similar proteins. Calumenin is an endo/sarcoplasmic reticulum (ER/SR) resident low-affinity Ca2+-binding protein that contains six EF-hand domains and a C-terminal SR retention signal His-Asp-Glu-Phe (HDEF) tetrapeptide. It functions as a novel regulator of SERCA2, and its expressional changes are tightly coupled with Ca2+-cycling of cardiomyocytes. It is also broadly involved in haemostasis and in the pathophysiology of thrombosis. Moreover, the extracellular calumenin acts as a suppressor of cell migration and tumor metastasis. RCN-1 is an endoplasmic reticulum resident Ca2+-binding protein with a carboxyl-terminal His-Asp-Glu-Leu (HDEL) tetrapeptide signal. It acts as a potential negative regulator of B-RAF activation and can negatively modulate cardiomyocyte hypertrophy by inhibition of the mitogen-activated protein kinase signalling cascade. It also plays a key role in the development of doxorubicin-associated resistance. RCN-3 is a putative six EF-hand Ca2+-binding protein that contains five RXXR (X is any amino acid) motifs and a C-terminal ER retrieval signal HDEL tetrapeptide. The RXXR motif represents the target sequence of subtilisin-like proprotein convertases (SPCs). RCN-3 is specifically bound to the paired basic amino-acid-cleaving enzyme-4 (PACE4) precursor protein and plays an important role in the biosynthesis of PACE4.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  21 KRLGRRFKKLDLDKSGSLSVEEFMSLPELRHNPLVRRVID----VFDTDGDGEVDFKEFILGTSQFSVKGDEEQKLRFA- 95
Cdd:cd16226    35 ERLGIIVDKIDKNGDGFVTEEELKDWIKYVQKKYIREDVDrqwkEYDPNKDGKLSWEEYKKATYGFLDDEEEDDDLHESy 114

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1493556010  96 ----------FSIYDMDKDGYISNGELFQVLKMMVGNNLTDWqlqqLVDKTIIILDKDGDGKISFEEF 153
Cdd:cd16226   115 kkmirrderrWKAADQDGDGKLTKEEFTAFLHPEEFPHMRDI----VVQETLEDIDKNKDGFISLEEY 178

EF-hand, calcium binding motif, found in mitochondrial calcium uptake proteins MICU1, MICU2, MICU3, and similar proteins; This family includes mitochondrial calcium uptake protein MICU1 and its two additional paralogs, MICU2 and MICU3. MICU1 localizes to the inner mitochondrial membrane (IMM). It functions as a gatekeeper of the mitochondrial calcium uniporter (MCU) and regulates MCU-mediated mitochondrial Ca2+ uptake, which is essential for maintaining mitochondrial homoeostasis. MICU1 and MICU2 are physically associated within the uniporter complex and are co-expressed across all tissues. They may play non-redundant roles in the regulation of the mitochondrial calcium uniporter. At present, the precise molecular function of MICU2 and MICU3 remain unclear. MICU2 may play possible roles in Ca2+ sensing and regulation of MCU, calcium buffering with a secondary impact on transport or assembly and stabilization of MCU. MICU3 likely has a role in mitochondrial calcium handling. All members in this family contains an N-terminal mitochondrial targeting sequence (MTS) as well as two evolutionarily conserved canonical Ca2+-binding EF-hands separated by a long stretch of residues predicted to form alpha-helices.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  27 FKKLDLDKSGSLSVEEFMSLPEL--RHNPLVRRVIDV------------------FDTDGDGEVDFKEFILGTSQFSVKG 86
Cdd:cd15900     6 FKMFDLDGDGELDKEEFNKVQSIirSQTSVGQRHRDHtngestklgmnstlaryfFGKDGKQKLSIEKFLEFQENLQEEI 85

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1493556010  87 DEeqkLRFAFSIYDMdKDGYISNGELFQVLKMMVGNNLTDwqlqQLVDKTIIILDKDGDGKISFEEFSAVVRD 159
Cdd:cd15900    86 DD---VDTALTFYHL-AGASIDRKTFKRAAKVVAGVELSD----HVVDVVFTIFDEDGDGILSHKEFISVMKD 150

EF-hand motif found in eukaryotic phosphoinositide-specific phospholipase C (PI-PLC, EC 3.1.4.11) isozymes; PI-PLC isozymes are signaling enzymes that hydrolyze the membrane phospholipids phosphatidylinositol-4,5-bisphosphate (PIP2) to generate two important second messengers in eukaryotic signal transduction cascades, Inositol 1,4,5-trisphosphate (InsP3) and diacylglycerol (DAG). InsP3 triggers inflow of calcium from intracellular stores, while DAG, together with calcium, activates protein kinase C, which goes on to phosphorylate other molecules, leading to altered cellular activity. Calcium is required for the catalysis. This family corresponds to the four EF-hand motifs containing PI-PLC isozymes, including PI-PLC-beta (1-4), -gamma (1-2), -delta (1,3,4), -epsilon (1), -zeta (1), eta (1-2). Lower eukaryotes such as yeast and slime molds contain only delta-type isozymes. In contrast, other types of isoforms present in higher eukaryotes. This family also includes 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase 1 (PLC1) from fungi. Some homologs from plants contain only two atypical EF-hand motifs and they are not included. All PI-PLC isozymes except sperm-specific PI-PLC-zeta share a core set of domains, including an N-terminal pleckstrin homology (PH) domain, four atypical EF-hand motifs, a PLC catalytic core, and a single C2 domain. PI-PLC-zeta lacks the PH domain. The PLC catalytic core domain is a TIM barrel with two highly conserved regions (X and Y) split by a highly degenerate linker sequence. Most of EF-hand motifs found in PI-PLCs consist of a helix-loop-helix structure, but lack residues critical to metal binding. Moreover, the EF-hand region of most of PI-PLCs may have an important regulatory function, but it has yet to be identified. However, PI-PLC-zeta is a key exception. It is responsible for Ca2+ oscillations in fertilized oocytes and exhibits a high sensitivity to Ca2+ mediated through its EF-hand domain. In addition, PI-PLC-eta2 shows a canonical EF-loop directing Ca2+-sensitivity and thus can amplify transient Ca2+ signals. Also it appears that PI-PLC-delta1 can regulate the binding of PH domain to PIP2 in a Ca2+-dependent manner through its functionally important EF-hand domains. PI-PLCs can be activated by a variety of extracellular ligands, such as growth factors, hormones, cytokines and lipids. Their activation has been implicated in tumorigenesis and/or metastasis linked to migration, proliferation, growth, inflammation, angiogenesis and actin cytoskeleton reorganization. PI-PLC-beta isozymes are activated by G-protein coupled receptor (GPCR) through different mechanisms. However, PI-PLC-gamma isozymes are activated by receptor tyrosine kinase (RTK), such as Rho and Ras GTPases. In contrast, PI-PLC-epsilon are activated by both GPCR and RTK. PI-PLC-delta1 and PLC-eta 1 are activated by GPCR-mediated calcium mobilization. The activation mechanism for PI-PLC-zeta remains unclear.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  27 FKKLDLDKSGSLSVEEFMSLPELRHNPL----VRRVIDVFDTDGDGEVDFKEFILGTSQFSVKGDeeqkLRFAFSIYDMD 102
Cdd:cd15898     6 WIKADKDGDGKLSLKEIKKLLKRLNIRVsekeLKKLFKEVDTNGDGTLTFDEFEELYKSLTERPE----LEPIFKKYAGT 81

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1493556010 103 KDGYISNGELFQVLKMMVGNNLTDWQLQQLVDKtiiILDKDGDGKISFEEFS 154
Cdd:cd15898    82 NRDYMTLEEFIRFLREEQGENVSEEECEELIEK---YEPERENRQLSFEGFT 130

EF-hand, calcium binding motif, found in homologs of mammalian apoptosis-linked gene 2 protein (ALG-2); The family includes some homologs of mammalian apoptosis-linked gene 2 protein (ALG-2) mainly found in lower eukaryotes, such as a parasitic protist Leishmarua major and a cellular slime mold Dictyostelium discoideum. These homologs contains five EF-hand motifs. Due to the presence of unfavorable residues at the Ca2+-coordinating positions, their non-canonical EF4 and EF5 hands may not bind Ca2+. Two Dictyostelium PEF proteins are the prototypes of this family. They may bind to cytoskeletal proteins and/or signal-transducing proteins localized to detergent-resistant membranes named lipid rafts, and occur as monomers or weak homo- or heterodimers like ALG-2. They can serve as a mediator for Ca2+ signaling-related Dictyostehum programmed cell death (PCD).

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1493556010  92 LRFAFSIYDMDKDGYISNGELFQVLKMmvGNNLTDwqlQQLVDKTIIILDKDGDGKISFEEFSAV 156
Cdd:cd16185     2 LRQWFRAVDRDRSGSIDVNELQKALAG--GGLLFS---LATAEKLIRMFDRDGNGTIDFEEFAAL 61

EF-hand, calcium binding motif, found in beta-parvalbumin; Beta-parvalbumin, also termed Oncomodulin-1 (OM), is a small calcium-binding protein that is expressed in hepatomas, as well as in the blastocyst and the cytotrophoblasts of the placenta. It is also found to be expressed in the cochlear outer hair cells of the organ of Corti and frequently expressed in neoplasms. Mammalian beta-parvalbumin is secreted by activated macrophages and neutrophils. It may function as a tissue-specific Ca2+-dependent regulatory protein, and may also serve as a specialized cytosolic Ca2+ buffer. Beta-parvalbumin acts as a potent growth-promoting signal between the innate immune system and neurons in vivo. It has high and specific affinity for its receptor on retinal ganglion cells (RGC) and functions as the principal mediator of optic nerve regeneration. It exerts its effects in a cyclic adenosine monophosphate (cAMP)-dependent manner and can further elevate intracellular cAMP levels. Moreover, beta-parvalbumin is associated with efferent function and outer hair cell electromotility, and can identify different hair cell types in the mammalian inner ear. Beta-parvalbumin is characterized by the presence of three consecutive EF-hand motifs (helix-loop-helix) called AB, CD, and EF, but only CD and EF can chelate metal ions, such as Ca2+ and Mg2+. The EF site displays a high-affinity for Ca2+/Mg2+, and the CD site is a low-affinity Ca2+-specific site. In addition, beta-parvalbumin is distinguished from other parvalbumins by its unusually low isoelectric point (pI = 3.1) and sequence eccentricities (e.g., Y57-L58-D59 instead of F57-I58-E59).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  71 DFKEFiLGTSQFSVKGDEEQKLrfAFSIYDMDKDGYISNGELFQVLKMM--VGNNLTDWQLQQLVDKTiiilDKDGDGKI 148
Cdd:cd16255    18 NFKKF-FATSGLSKKSADDVKK--VFEIIDQDKSGFIEEEELKLFLQNFssGARELTDAETKAFLKAG----DSDGDGKI 90

                  ....*....
gi 1493556010 149 SFEEFSAVV 157
Cdd:cd16255    91 GVEEFQALV 99

EF-hand, calcium binding motif, found in 45 kDa calcium-binding protein (Cab45); Cab45, also termed stromal cell-derived factor 4 (SDF-4), is a soluble, lumenal Golgi resident low-affinity Ca2+-binding protein that contains six copies of the EF-hand Ca2+-binding motif. It is required for secretory pathway calcium ATPase1 (SPCA1)-dependent Ca2+ import into the trans-Golgi network (TGN) and plays an essential role in Ca2+-dependent secretory cargo sorting at the TGN.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  15 FDNDEIKRLGRR----FKKLDLDKSGSLSVEEFMS---------LPE-LRHNplvRRVIDVFDTDGDGEVDFKEF----- 75
Cdd:cd16225    24 FEEDSEPKKRKKlkeiFKKVDVNTDGFLSAEELEDwimektqehFQEaVEEN---EQIFKAVDTDKDGNVSWEEYrvhfl 100

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  76 -------------ILGTSQFSVKGDEEQKL---RFAFSIYDMDKDGYISNGELF---------QVLKMMVGNNLTDwqlq 130
Cdd:cd16225   101 lskgyseeeaeekIKNNEELKLDEDDKEVLdryKDRWSQADEPEDGLLDVEEFLsfrhpehsrGMLKNMVKEILHD---- 176

                         170       180
                  ....*....|....*....|....*.
gi 1493556010 131 qlvdktiiiLDKDGDGKISFEEFSAV 156
Cdd:cd16225   177 ---------LDQDGDEKLTLDEFVSL 193

centrin; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  55 VRRVIDVFDTDGDGEVDFKEF--ILGTSQFSVKGDEEQKLrfafsIYDMDKDGY--ISNGELFQVLKMMVGNNLTDwqlq 130
Cdd:PTZ00183   19 IREAFDLFDTDGSGTIDPKELkvAMRSLGFEPKKEEIKQM-----IADVDKDGSgkIDFEEFLDIMTKKLGERDPR---- 89

                          90       100       110
                  ....*....|....*....|....*....|
gi 1493556010 131 QLVDKTIIILDKDGDGKISFEEFSAVVRDL 160
Cdd:PTZ00183   90 EEILKAFRLFDDDKTGKISLKNLKRVAKEL 119

serine/threonine protein phosphatase 2A regulatory subunit B" subunit gamma; Heterotrimeric serine/threonine protein phosphatase 2A (PP2A) consists of scaffolding (A), catalytic (C), and variable (B, B', and B") subunits. The variable subunits dictate subcellular localization and substrate specificity of the PP2A holoenzyme. This subfamily includes protein phosphatase subunit G5PR (also known as serine/threonine-protein phosphatase 2A regulatory subunit B'' subunit gamma, G4-1, G5pr, GDRM, SPGF36, or C14orf10) that is encoded by the PPP2R3C gene. It is involved in the control of the dynamic organization of the cortical cytoskeleton and plays an important role in the organization of interphase microtubule arrays in part through the regulation of nucleation geometry. G5PR is involved in the ontogeny of multiple organs, especially critical for testis development and spermatogenesis. PPP2R3C gene variants cause syndromic 46,XY gonadal dysgenesis and impaired spermatogenesis in humans, and thus is emerging as a potential therapeutic target for male infertility.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  27 FKKLDLDKSGSLSVEEfmsLPELRHNPLVRRVID-VFDTDG--DGEVDFK---EFILGTSqfsvKGDEEQKLRFAFSIYD 100
Cdd:cd21505   227 YLNLDKDHNGMLSKQE---LSRYGKGTLTSVFIDrVFQECLtyNGEMDYKtflDFVLAME----NRKEPQALQYFFRILD 299

                          90       100       110
                  ....*....|....*....|....*....|....*...
gi 1493556010 101 MDKDGYISNGEL---FQ-VLKMMVGNNLTDWQLQQLVD 134
Cdd:cd21505   300 LKGQGYLTPFTLnyfFRaIQEKMKEHGQEPVSFEDVKD 337

EF-hand, calcium binding motif, found in parvalbumins; Parvalbumins are small, acidic, cytosolic EF-hand-containing Ca2+-buffer and Ca2+ transporter/shuttle proteins belonging to EF-hand superfamily. They are expressed by vertebrates in fast-twitch muscle cells, specific neurons of the central and peripheral nervous system, sensory cells of the mammalian auditory organ (Corti's cell), and some other cells, and characterized by the presence of three consecutive EF-hand motifs (helix-loop-helix) called AB, CD, and EF, but only CD and EF can chelate metal ions, such as Ca2+ and Mg2+. Thus, they may play an additional role in Mg2+ handling. Moreover, parvalbumins represent one of the major animal allergens. In metal-bound states, parvalbumins possess a rigid and stable tertiary structure and display strong allergenicity. In contrast, the metal-free parvalbumins are intrinsically disordered, and the loss of metal ions results in a conformational change that decreases their IgE binding capacity. Furthermore, parvalbumins have been widely used as a neuronal marker for a variety of functional brain systems. They also function as a Ca2+ shuttle transporting Ca2+ from troponin-C (TnC) to the sarcoplasmic reticulum (SR) Ca2+ pump during muscle relaxation. Thus they may facilitate myocardial relaxation and play important roles in cardiac diastolic dysfunction. Parvalbumins consists of alpha- and beta- sublineages, which can be distinguished on the basis of isoelectric point (pI > 5 for alpha; pI

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  71 DFKEFiLGTSQFSVKGDEEqkLRFAFSIYDMDKDGYISNGELFQVLKMMV--GNNLTDWQLQQLVDKTiiilDKDGDGKI 148
Cdd:cd16253    18 DHKAF-FKAVGLSKKSPAD--IKKVFNILDQDKSGFIEEEELKLFLKNFSdgARVLSDKETKNFLAAG----DSDGDGKI 90

                          90
                  ....*....|
gi 1493556010 149 SFEEFSAVVR 158
Cdd:cd16253    91 GVDEFKSMVK 100

EF-hand, extracellular calcium-binding (EC) motif, found in secreted protein acidic and rich in cysteine (SPARC)-like proteins; The SPARC protein family represents a diverse group of proteins that share a follistatin-like (FS) domain and an extracellular calcium-binding (EC) domain with two EF-hand motifs. It includes SPARC (for secreted protein acidic and rich in cysteine, also termed osteonectin/ON, or basement-membrane protein 40/BM-40), SPARC-like protein 1 (for secreted protein, acidic and rich in cysteines-like 1/ SPARCL1, also termed high endothelial venule protein/Hevi, or MAST 9, or SC-1, or RAGS-1, or QR1, or ECM 2), testicans 1, 2, and 3 (also termed SPARC/osteonectin, CWCV, and Kazal-like domains proteoglycans, or SPOCK), secreted modular calcium-binding protein SMOC-1 (also termed SPARC-related modular calcium-binding protein 1) and SMOC-2 (also termed SPARC-related modular calcium-binding protein 2, or smooth muscle-associated protein 2/SMAP-2), follistatin-related protein 1 (FRP-1, also termed follistatin-like protein 1/fstl-1, TSC-36/Flik, TGF-beta inducible protein). The SPARC proteins have been implicated in modulating cell interaction with the extracellular milieu, including regulation of extracellular matrix assembly and deposition, counter-adhesion, effects on extracellular protease activity, and modulation of growth factor/cytokine signaling pathways, as well as in development and disease.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1493556010   2 GNEASYPAEMCSHFDNDEIKR-LGRRFKKLDLDKSGSLSVEEFMSL--PELRHNPLVRRVIDVFDTDGDGEVDFKEFIL 77
Cdd:cd00252    25 ENRSYDNNKRGHDLSGTMRKEiAQWEFDNLDNNKDGKLDKRELAPFraPLMPLEHCARGFFESCDLNKDKKISLQEWLG 103

EF-hand, calcium binding motif, found in calcium uptake protein 3, mitochondrial (MICU3) and similar proteins; MICU3, also termed EF-hand domain-containing family member A2 (EFHA2), is a paralog of MICU1 and notably found in the central nervous system (CNS) and skeletal muscle. At present, the precise molecular function of MICU3 remains unclear. It likely has a role in mitochondrial calcium handling. MICU3 contains an N-terminal mitochondrial targeting sequence (MTS) as well as two evolutionarily conserved canonical Ca2+-binding EF-hands separated by a long stretch of residues predicted to form alpha-helices.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1493556010  56 RRVIDVFDTDGDGEVDFKEF-----ILGTSQ---FSVKGDEE-----------------QKLRFAFSIYDMdKDGYISNG 110
Cdd:cd16175     3 RIAFNMFDTDGNEMVDKKEFlvlqeIFRTLLvhfFGKKGKAElnfedfyrfmdnlqtevEDFTIAMRMYTF-ADRSISQD 81

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*....
gi 1493556010 111 ELFQVLKMMVGNNLTdwqlQQLVDKTIIILDKDGDGKISFEEFSAVVRD 159
Cdd:cd16175    82 EFARAVKVCTGLKLS----PHLVNTVFKIFDVDGDGQLSYKEFIGIMKD 126

EF-hand, calcium binding motif; EF-hands are calcium-binding motifs that occur at least in pairs. Links between disease states and genes encoding EF-hands, particularly the S100 subclass, are emerging. Each motif consists of a 12 residue loop flanked on either side by a 12 residue alpha-helix. EF-hands undergo a conformational change unpon binding calcium ions.

                           10        20
                   ....*....|....*....|..
gi 1493556010   55 VRRVIDVFDTDGDGEVDFKEFI 76
Cdd:smart00054   2 LKEAFRLFDKDGDGKIDFEEFK 23