The penta-EF hand (PEF) family; The penta-EF hand (PEF) family contains a group of five EF-hand calcium-binding proteins, including several classical calpain large catalytic subunits (CAPN1, 2, 3, 8, 9, 11, 12, 13, 14), two calpain small subunits (CAPNS1 and CAPNS2), as well as non-calpain PEF proteins, ALG-2 (apoptosis-linked gene 2, also termed programmed cell death protein 6, PDCD6), peflin, sorcin, and grancalcin. Based on the sequence similarity of EF1 hand, ALG-2 and peflin have been classified into group I PEF proteins. Calcium-dependent protease calpain subfamily members, sorcin and grancalcin, are group II PEF proteins. Calpains (EC 3.4.22.17) are calcium-activated intracellular cysteine proteases that play important roles in the degradation or functional modulation in a variety of substrates. They have been implicated in a number of physiological processes such as cell cycle progression, remodeling of cytoskeletal-cell membrane attachments, signal transduction, gene expression and apoptosis. ALG-2 is a pro-apoptotic factor that forms a homodimer in the cell or a heterodimer with its closest paralog peflin through their EF5s. Peflin is a 30-kD PEF protein with a longer N-terminal hydrophobic domain than any other member of the PEF family, and it contains nine nonapeptide (A/PPGGPYGGP) repeats. It exists only as a heterodimer with ALG-2. The dissociation of heterodimer occurs in the presence of Ca2+. ALG-2 interacts with various proteins in a Ca2+-dependent manner. Sorcin (for soluble resistance-related calcium binding protein) is a soluble resistance-related calcium-binding protein that participates in the regulation of calcium homeostasis in cells. Grancalcin is a cytosolic Ca2+-binding protein specifically expressed in neutrophils and monocytes/macrophages. It plays a key role in leukocyte-specific functions that are responsible for host defense. Grancalcin can form a heterodimer together with sorcin. Members in this family contain five EF-hand motifs attached to an N-terminal region of variable length containing one or more short Gly/Pro-rich sequences. These proteins form homodimers or heterodimers through pairing between the 5th EF-hands from the two molecules. Unlike calmodulin, the PEF domains do not undergo major conformational changes upon binding Ca2+.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   1 MEICADELKKVLNTVVNKHKDLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSY 80
Cdd:cd16190  14 MEISADELRSVLNRVVKKHKDLKTEGFTLESCRSMIALMDTDGSGKLNLQEFRHLWNKIKQWQKIFKRYDTDKSGTINSY 93

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 27765080  81 EMRNAVNDAGFHLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTMYA 156
Cdd:cd16190  94 EMRNAVNDAGFRLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTMYA 169

Calcium-activated neutral; CAPN3, also termed calcium-activated neutral proteinase 3 (CANP 3), or calpain L3, or calpain p94, or muscle-specific calcium-activated neutral protease 3, or new calpain 1 (nCL-1), is a calpain large subunit that is mainly expressed in skeletal muscle, or lens. The skeletal muscle-specific CAPN3 are pathologically associated with limb girdle muscular dystrophy type 2A (LGMD2A). Its autolytic activity can be positively regulated by calmodulin (CaM), a known transducer of the calcium signal. CAPN3 is also involved in human melanoma tumorigenesis and progression. It impairs cell proliferation and stimulates oxidative stress-mediated cell death in melanoma cells. Moreover, it plays an important role in sarcomere remodeling and mitochondrial protein turnover. Furthermore, the phosphorylated skeletal muscle-specific CAPN3 acts as a myofibril structural component and may participate in myofibril-based signaling pathways. In the eye, the lens-specific CAPN3, together with CAPN2, is responsible for proteolytic cleavages of alpha and beta-crystallin. Overactivated alpha and beta-crystallin can lead to cataract formation. CAPN3 exists as a homodimer, rather than a heterodimer with the calpain small subunit. It may also form heterodimers with other calpain large subunits. CAPN3 contains a long N-terminal region, followed by a calpain cysteine protease (CysPc) domain, a C2-domain-like (C2L) domain, and a C-terminal Ca2+-binding penta-EF-hand (PEF) domain. Ca2+ binding at EF5 of the CAPN3 PEF domain is a distinct feature not observed in other calpain isoforms.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   1 MEICADELKKVLNTVVNKHKDLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSY 80
Cdd:cd16190  14 MEISADELRSVLNRVVKKHKDLKTEGFTLESCRSMIALMDTDGSGKLNLQEFRHLWNKIKQWQKIFKRYDTDKSGTINSY 93

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 27765080  81 EMRNAVNDAGFHLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTMYA 156
Cdd:cd16190  94 EMRNAVNDAGFRLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTMYA 169

centrin; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   66 FKHYDTDQSGTINSYEMRNAVNDAGFHLNN-QLYDIITMRYADKHMNIDFDSFI-CCFVRL------EGMFRAFHAFDKD 137
Cdd:PTZ00183  23 FDLFDTDGSGTIDPKELKVAMRSLGFEPKKeEIKQMIADVDKDGSGKIDFEEFLdIMTKKLgerdprEEILKAFRLFDDD 102

                         90
                 ....*....|
gi 27765080  138 GDGIIKLNVL 147
Cdd:PTZ00183 103 KTGKISLKNL 112

Calcium-activated neutral; CAPN3, also termed calcium-activated neutral proteinase 3 (CANP 3), or calpain L3, or calpain p94, or muscle-specific calcium-activated neutral protease 3, or new calpain 1 (nCL-1), is a calpain large subunit that is mainly expressed in skeletal muscle, or lens. The skeletal muscle-specific CAPN3 are pathologically associated with limb girdle muscular dystrophy type 2A (LGMD2A). Its autolytic activity can be positively regulated by calmodulin (CaM), a known transducer of the calcium signal. CAPN3 is also involved in human melanoma tumorigenesis and progression. It impairs cell proliferation and stimulates oxidative stress-mediated cell death in melanoma cells. Moreover, it plays an important role in sarcomere remodeling and mitochondrial protein turnover. Furthermore, the phosphorylated skeletal muscle-specific CAPN3 acts as a myofibril structural component and may participate in myofibril-based signaling pathways. In the eye, the lens-specific CAPN3, together with CAPN2, is responsible for proteolytic cleavages of alpha and beta-crystallin. Overactivated alpha and beta-crystallin can lead to cataract formation. CAPN3 exists as a homodimer, rather than a heterodimer with the calpain small subunit. It may also form heterodimers with other calpain large subunits. CAPN3 contains a long N-terminal region, followed by a calpain cysteine protease (CysPc) domain, a C2-domain-like (C2L) domain, and a C-terminal Ca2+-binding penta-EF-hand (PEF) domain. Ca2+ binding at EF5 of the CAPN3 PEF domain is a distinct feature not observed in other calpain isoforms.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   1 MEICADELKKVLNTVVNKHKDLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSY 80
Cdd:cd16190  14 MEISADELRSVLNRVVKKHKDLKTEGFTLESCRSMIALMDTDGSGKLNLQEFRHLWNKIKQWQKIFKRYDTDKSGTINSY 93

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 27765080  81 EMRNAVNDAGFHLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTMYA 156
Cdd:cd16190  94 EMRNAVNDAGFRLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTMYA 169

Penta-EF hand, calcium binding motifs, found in calcium-dependent protease small subunit CAPNS1 and CAPNS2; CAPNS1, also termed calpain small subunit 1 (CSS1), or calcium-activated neutral proteinase small subunit (CANP small subunit), or calcium-dependent protease small subunit (CDPS), or calpain regulatory subunit, is a common 28-kDa regulatory calpain subunit encoded by the calpain small 1 (Capns1, also known as Capn4) gene. It acts as a binding partner to form a heterodimer with the 80 kDa calpain large catalytic subunit and is required in maintaining the activity of calpain. CAPNS1 plays a significant role in tumor progression of human cancer, and functions as a potential therapeutic target in human hepatocellular carcinoma (HCC), nasopharyngeal carcinoma (NPC), glioma, and clear cell renal cell carcinoma (ccRCC). It may be involved in regulating migration and cell survival through binding to the SH3 domain of Ras GTPase-activating protein (RasGAP). It may also modulate Akt/FoxO3A signaling and apoptosis through PP2A. CAPNS1 contains an N-terminal glycine rich domain and a C-terminal PEF-hand domain. CAPNS2, also termed calpain small subunit 2 (CSS2), is a novel tissue-specific 30 kDa calpain small subunit that lacks two oligo-Gly stretches characteristic of the N-terminal Gly-rich domain of CAPNS1. CAPNS2 acts as a chaperone for the calpain large subunit, and appears to be the functional equivalent of CAPNS1. However, CAPNS2 binds the large subunit much more weakly than CAPNS1 and it does not undergo the autolytic conversion typical of CAPNS1.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   1 MEICADELKKVLNTVVNKHKDLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSY 80
Cdd:cd16188  14 MEVSATELMNILNKVVTRHPDLKTDGFGIDTCRSMVAVMDSDTTGKLGFEEFKYLWNNIKKWQGIYKQFDTDRSGTIGSQ 93

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 27765080  81 EMRNAVNDAGFHLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTMYA 156
Cdd:cd16188  94 ELPGAFEAAGFHLNEQLYQMIIRRYSDEDGNMDFDNFISCLVRLDAMFRAFKSLDKDGTGQIQVNIQEWLQLTMYS 169

Penta-EF hand, calcium binding motifs, found in mu-type calpain (CAPN1), m-type calpain (CAPN2), and similar proteins; The family includes mu-type calpain (CAPN1) and m-type calpain (CAPN2), both of which are ubiquitously expressed 80-kDa Ca2+-dependent intracellular cysteine proteases that contain a short N-terminal anchor helix, followed by a calpain cysteine protease (CysPc) domain, a C2-domain-like (C2L) domain, and a C-terminal Ca2+-binding penta-EF-hand (PEF) domain. The catalytic subunit CAPN1 or CAPN2 in complex with a regulatory subunit encoded by CAPNS1 forms a mu- or m-calpain heterodimer, respectively.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   1 MEICADELKKVLNTVVNKHKDLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSY 80
Cdd:cd16189  14 SEISAFELQTILNKVLSKRKDIKTDGFSLETCRNMVNLLDKDGSGKLGLVEFQILWTKIQKYLKIYKKFDTDGSGTMSSY 93

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 27765080  81 EMRNAVNDAGFHLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTM 154
Cdd:cd16189  94 EMRLALEEAGFKLNNQLHQVLVARYADQELTIDFDNFVRCLVRLELLFKIFKQLDKDNTGTIELDLIQWLSFSL 167

Penta-EF hand, calcium binding motifs, found in calpain-9 (CAPN9); CAPN9, also termed digestive tract-specific calpain, or new calpain 4 (nCL-4), or protein CG36, is a calpain large subunit predominantly expressed in gastrointestinal tract. It plays a physiological role in the suppression of tumorigenesis. It acts as an important biomolecule link for the regression of colorectal cancer via intracellular calcium homeostasis. CAPN9 may also play a critical role in lumen formation. Moreover, CAPN9, together with CAPN8, forms an active protease complex, G-calpain, in which both proteins are essential for stability and activity. The G-Calpain has been implicated in gastric mucosal defense. Furthermore, down-regulation of calpain 9 has been linked to hypertensive heart and kidney disease in salt-sensitive Dahl rats. CAPN9 contains a short N-terminal anchor helix, followed by a calpain cysteine protease (CysPc) domain, a C2-domain-like (C2L) domain, and a C-terminal Ca2+-binding penta-EF-hand (PEF) domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   1 MEICADELKKVLNTVVNKHKDLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSY 80
Cdd:cd16192  14 LEISAEELQYVLNAVLARTKEIKFKKLSLLSCKNIISLMDTSGNGKLGFSEFKVFWDKLKKWIGLFLKYDADRSGTMSSY 93

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 27765080  81 EMRNAVNDAGFHLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTM 154
Cdd:cd16192  94 ELRSALKAAGFQLNNQLLQLIVLRYADDYLQIDFDDFLNCLVRLENSFRVFQALDTKNTGEISLNMLEFILLTM 167

Penta-EF hand, calcium binding motifs, found in Drosophila melanogaster calpain-A (CalpA), calpain-B (CalpB), and similar proteins; The family contains two calpains that have been found in Drosophila, CalpA and CalpB. CalpA, also termed calcium-activated neutral proteinase A (CANP A), or calpain-A catalytic subunit, is a Drosophila calpain homolog specifically expressed in a few neurons in the central nervous system, in scattered endocrine cells in the midgut, and in blood cells. CalpB, also termed calcium-activated neutral proteinase B (CANP B), contains calpain-B catalytic subunit 1 and calpain-B catalytic subunit 2. Both CalpA and CalpB are closely related to that of vertebrate calpains, and they share similar domain architecture, which consists of four domains: the N-terminal domain I, the catalytic domain II carrying the three active site residues, Cys, His and Asn, the Ca2+-regulated phospholipid-binding domain III, and penta-EF-hand Ca2+-binding domain IV. Besides, CalpA and CalpB display some distinguishing structural features that are not found in mammalian typical calpains. CalpA harbors a 76 amino acid long hydrophobic stretch inserted in domain IV, which may be involved in membrane attachment of this enzyme. CalpB has an unusually long N-terminal tail of 224 amino acids, which belongs to the class of intrinsically unstructured proteins (IUP) and may become ordered upon binding to target protein(s). Moreover, they do not need small regulatory subunits for their catalytic activity, and their proteolytic function is not regulated by an intrinsic inhibitor as the Drosophila genome contains neither regulatory subunit nor calpastatin orthologs. As a result, they may exist as a monomer or perhaps as a homo- or heterodimer together with a second large subunit. Furthermore, both CalpA and CalpB are dispensable for viability and fertility and do not share vital functions during Drosophila development. Phosphatidylinositol 4,5-diphosphate, phosphatidylinositol 4-monophosphate, phosphatidylinositol, and phosphatidic acid can stimulate the activity and the rate of activation of CalpA, but not CalpB. Calpain A modulates Toll responses by limited Cactus/IkappaB proteolysis. CalpB directly interacts with talin, an important component of the focal adhesion complex, and functions as an important modulator in border cell migration within egg chambers, which may act via the digestion of talin. CalpB can be phosphorylated by cAMP-dependent protein kinase (protein kinase A, PKA; EC 2.7.11.11) at Ser240 and Ser845, as well as by mitogen-activated protein kinase (ERK1 and ERK2; EC 2.7.11.24) at Thr747. The activation of the ERK pathway by extracellular signals results in the phosphorylation and activation of calpain B. In Schneider cells (S2), calpain B was mainly in the cytoplasm and upon a rise in Ca2+ the enzyme adhered to intracellular membranes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   1 MEICADELKKVLNTVVNKhkDLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSY 80
Cdd:cd16196  14 MEIDAYELQDILNTAFKK--DFPFDGFSLDACRSMVAMMDVDRSGKLGFEEFKKLWEDLRSWKRVFKLFDTDGSGSFSSF 91

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 27765080  81 EMRNAVNDAGFHLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTMYA 156
Cdd:cd16196  92 ELRNALNSAGFRLSNATLNALVLRYSNKDGRISFDDFIMCAVKLKTMFEIFKEKDPRGGGRATFNLDEFLESTMYS 167

Penta-EF hand, calcium binding motifs, found in calpain-8 (CAPN8); CAPN8, also termed new calpain 2 (nCL-2), or stomach-specific M-type calpain, is a calpain large subunit predominantly expressed in the stomach. It appears to be involved in membrane trafficking in the gastric surface mucus cells (pit cells), via its location at the Golgi and interaction with the beta-subunit of coatomer complex (beta-COP) of vesicles derived from the Golgi. Moreover, CAPN8, together with CAPN9, forms an active protease complex, G-calpain, in which both proteins are essential for stability and activity. The G-Calpain has been implicated in gastric mucosal defense. CAPN8 exists as both a monomer and homo-oligomer, but not as a heterodimer with the conventional calpain regulatory subunit (30K). The monomer and homodimer forms predominate. CAPN8 contains a short N-terminal anchor helix, followed by a calpain cysteine protease (CysPc) domain, a C2-domain-like (C2L) domain, and a C-terminal Ca2+-binding penta-EF-hand (PEF) domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   1 MEICADELKKVLNTVVNKHKDLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSY 80
Cdd:cd16191  14 CEVTANELQTILNRVLSKRKDIKSDGFTINTCREMISLLDTDGTGTLGLVEFRILWMKIQKYLAIYKKVDSDRSGTIDAH 93

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 27765080  81 EMRNAVNDAGFHLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTM 154
Cdd:cd16191  94 EMRNALQEAGFTLNNKIQQSIVQRYASNKLTINFDGFIACMIRLETLFKMFQLLDKDKSGVVQLSLAEWLCCTL 167

Penta-EF hand, calcium binding motifs, found in calpain-11 (CAPN11); CAPN11, also termed calcium-activated neutral proteinase 11 (CANP 11), is a mammalian orthologue of micro/m calpain. It is one of the calpain large subunits that appears to be exclusively expressed in certain cells of the testis. It may be involved in regulating calcium-dependent signal transduction events during meiosis and sperm functional processes. CAPN11 contains a short N-terminal anchor helix, followed by a calpain cysteine protease (CysPc) domain, a C2-domain-like (C2L) domain, and a C-terminal Ca2+-binding penta-EF-hand (PEF) domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   2 EICADELKKVLNTVVNKHKDLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSYE 81
Cdd:cd16193  15 EVDMYELQKLLNRMAIKFKSFKTKGFSLDVCRRMINLMDKDGSGKLGLHEFKILWKKIKKWMEIFKECDQDRSGNLNSYE 94

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 27765080  82 MRNAVNDAGFHLNNQLYDIITMRYADKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTMY 155
Cdd:cd16193  95 MRLAIEKAGIKMNNRVTEVVVARYADDNMIVDFDSFINCFLRLKAMFAFFLSMDTKKTGSICLSINQWLQITMW 168

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 27765080   3 ICADELKKVLNTVVNKHkdlkthgFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSYEM 82
Cdd:cd16180  17 ISAKELQRALSNGDWTP-------FSIETVRLMINMFDRDRSGTINFDEFVGLWKYIQDWRRLFRRFDRDRSGSIDFNEL 89

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 27765080  83 RNAVNDAGFHLNNQLYDIITMRYaDKHMN--IDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLN 145
Cdd:cd16180  90 QNALSSFGYRLSPQFVQLLVRKF-DRRRRgsISFDDFVEACVTLKRLTDAFRKYDTNRTGYATIS 153

Penta-EF hand, calcium binding motifs, found in sorcin; Sorcin, also termed 22 kDa Ca2+-binding protein, CP-22, or V19, is a soluble resistance-related calcium-binding protein that is expressed in normal mammalian tissues, such as the liver, lungs and heart. The up-regulation of sorcin is correlated with a number of cancer types, including colorectal, gastric and breast cancer. It may represent a therapeutic target for reversing tumor multidrug resistance (MDR). Sorcin participates in the regulation of calcium homeostasis in cells and is necessary for the activation of mitosis and cytokinesis. It enhances metastasis and promotes epithelial-to-mesenchymal transition of colorectal cancer. Moreover, sorcin has been implicated in the regulation of intracellular Ca2+ cycling and cardiac excitation-contraction coupling. It displays the anti-apoptotic properties via the modulation of mitochondrial Ca2+ handling in cardiac myocytes. It can target and activate the sarcolemmal Na+/Ca2+ exchanger (NCX1) in cardiac muscle. Meanwhile, sorcin modulates cardiac L-type Ca2+ current by functional interaction with the alpha1C subunit. It also associates with calcium/calmodulin-dependent protein kinase IIdeltaC (CaMKIIdelta(C)) and further modulates ryanodine receptor (RyR) function in cardiac myocytes. Furthermore, sorcin may act as a Ca2+ sensor for glucose-induced nuclear translocation and the activation of carbohydrate-responsive element-binding protein (ChREBP)-dependent genes. As a mitochondrial chaperone TRAP1 interactor, sorcin involves in mitochondrial metabolism through the TRAP1 pathway. In addition, sorcin may regulate the inhibition of type I interferon response in cells through interacting with foot-and-mouth disease virus (FMDV) VP1. Sorcin contains a flexible glycine and proline-rich N-terminal extension and five EF-hand motifs that associate with membranes in a calcium-dependent manner. It may harbor three potential Ca2+ binding sites through its EF1, EF2 and EF3 hands. However, binding of only two Ca2+/monomer suffices to trigger the conformational change that exposes hydrophobic regions and leads to interaction with the respective targets. Sorcin forms homodimers through the association of the unpaired EF5 hand. Among the PEF proteins, sorcin is unique in that it contains potential phosphorylation sites by cAMP-dependent protein kinase (PKA), and it can form a tetramer at slightly acid pH values although remaining a stable dimer at neutral pH.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   2 EICADELKKVLNT--VVNKHKDlkthgFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINS 79
Cdd:cd16187  15 QIDADELQRCLTQsgIAGGYKP-----FNLETCRLMISMLDRDMSGTMGFNEFKELWAVLNGWRQHFISFDSDRSGTVDP 89

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 27765080  80 YEMRNAVNDAGFHLNNQLYDIITMRYAdKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTM 154
Cdd:cd16187  90 QELQKALTTMGFRLSPQAVNSIAKRYS-TNGKITFDDYIACCVKLRALTDSFRRRDTSQQGVVNFPYDDFIQCVM 163

Penta-EF hand, calcium binding motifs, found in grancalcin; Grancalcin (GCA) is a cytosolic Ca2+-binding protein specifically expressed in neutrophils and monocytes/macrophages. It displays a Ca2+-dependent translocation to granules and plasma membrane upon neutrophil activation, suggesting roles in granule-membrane fusion and degranulation of neutrophils. It may also play a role in the regulation of vesicle/granule exocytosis through the reversible binding of secretory vesicles and plasma membranes upon the presence of calcium. Moreover, GCA is involved in inflammation, as well as in the process of adhesion of neutrophils to fibronectin. It plays a key role in leukocyte-specific functions that are responsible for host defense, and affects the function of integrin receptors on immune cells through binding to L-plastin in the absence of calcium. Furthermore, GCA can strongly interact with sorcin to form a heterodimer, and further modulate the function of sorcin. GCA exists as homodimers in solution. It contains five EF-hand motifs attached to an N-terminal region of an approximately 50 residue-long segment rich in glycines and prolines. GCA binds two Ca2+ ions through its EF1 and EF3 hands.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   2 EICADELKKVLnTVVNKHKDLKThgFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSYE 81
Cdd:cd16186  15 EVDAEELQRCL-TQSGINGTYTP--FSLETCRIMIAMLDRDHTGKMGFNEFKELWAALNAWKQNFMTVDQDRSGTVEPHE 91

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 27765080  82 MRNAVNDAGFHLNNQLYDIITMRYAdKHMNIDFDSFICCFVRLEGMFRAFHAFDKDGDGIIKLNVLEWLQLTM 154
Cdd:cd16186  92 LRQAIGAMGYRLSPQTLTTIVKRYS-KNGRIYFDDYVACCVKLRALTDFFRRRDHMQQGSVNFIYDDFLQCTM 163

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 27765080   3 ICADELKKVLNtvvnkhkdLKTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLWNKIKAWQKIFKHYDTDQSGTINSYEM 82
Cdd:cd16185  17 IDVNELQKALA--------GGGLLFSLATAEKLIRMFDRDGNGTIDFEEFAALHQFLSNMQNGFEQRDTSRSGRLDANEV 88

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 27765080  83 RNAVNDAGFHLNNQLYDIITMRY-ADKHMNIDFDSFI--CCFVRLegMFRAFHAFDKDGDGIIKLNVLEWLQLTMY 155
Cdd:cd16185  89 HEALAASGFQLDPPAFQALFRKFdPDRGGSLGFDDYIelCIFLAS--ARNLFQAFDRQRTGRVTLDFNQFVYAAAN 162

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

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080  33 RSMIALMDTDGSGKLNLQEFHHLWNKIKAW----QKIFKHYDTDQSGTINSYEMRNAVND 88
Cdd:COG5126  72 RAAFDLLDTDGDGKISADEFRRLLTALGVSeeeaDELFARLDTDGDGKISFEEFVAAVRD 131

centrin; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   66 FKHYDTDQSGTINSYEMRNAVNDAGFHLNN-QLYDIITMRYADKHMNIDFDSFI-CCFVRL------EGMFRAFHAFDKD 137
Cdd:PTZ00183  23 FDLFDTDGSGTIDPKELKVAMRSLGFEPKKeEIKQMIADVDKDGSGKIDFEEFLdIMTKKLgerdprEEILKAFRLFDDD 102

                         90
                 ....*....|
gi 27765080  138 GDGIIKLNVL 147
Cdd:PTZ00183 103 KTGKISLKNL 112

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
                ....*....|....*....|....*....|....*....|....*....|....
gi 27765080   3 ICADELKKVLNTVvnkhkdlkTHGFTLESCRSMIALMDTDGSGKLNLQEFHHLW 56
Cdd:cd00051  17 ISADELKAALKSL--------GEGLSEEEIDEMIREVDKDGDGKIDFEEFLELM 62

calmodulin; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   58 KIKAWQKIFKHYDTDQSGTINSYEMRNAVNDAGFHLNNQ-LYDIITMRYADKHMNIDFDSFICCFVRL-------EGMFR 129
Cdd:PTZ00184   9 QIAEFKEAFSLFDKDGDGTITTKELGTVMRSLGQNPTEAeLQDMINEVDADGNGTIDFPEFLTLMARKmkdtdseEEIKE 88

                         90
                 ....*....|...
gi 27765080  130 AFHAFDKDGDGII 142
Cdd:PTZ00184  89 AFKVFDRDGNGFI 101

centrin; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 27765080   30 ESCRSMIALMDTDGSGKLNLQEFHHLWNKIKA-------WQKIFKHYDTDQSGTINSYEMRNAVNDAGFHLNN-QLYDII 101
Cdd:PTZ00183  53 EEIKQMIADVDKDGSGKIDFEEFLDIMTKKLGerdpreeILKAFRLFDDDKTGKISLKNLKRVAKELGETITDeELQEMI 132

                         90
                 ....*....|....*..
gi 27765080  102 TMRYADKHMNIDFDSFI 118
Cdd:PTZ00183 133 DEADRNGDGEISEEEFY 149

EF-hand domain;

                          10        20
                  ....*....|....*....|....*....
gi 27765080    62 WQKIFKHYDTDQSGTINSYEMRNAVNDAG 90
Cdd:pfam13405   2 LREAFKLFDKDGDGKISLEELRKALRSLG 30