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

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727  39 FIPSQEFST-YRQWKQKIVQAGDKDLDGQLDFEEFVHY-----LQDHEKKLRLVFKSLDKKNDGRIDAQEIMQSLRDLGV 112
Cdd:COG5126    21 VLERDDFEAlFRRLWATLFSEADTDGDGRISREEFVAGmeslfEATVEPFARAAFDLLDTDGDGKISADEFRRLLTALGV 100

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*..
gi 1622870727 113 kiSEQQAEKILKRIrtghfwgpvtymDKNGTMTIDWNE----WRDYH 155
Cdd:COG5126   101 --SEEEADELFARL------------DTDGDGKISFEEfvaaVRDYY 133

Mitochondrial carrier protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 288 ETLRIHERLVAGSLAGAIAQSSIYPMEVLKTRMAL---RKTGQYSGMLDCARRILAREGVAAFYKGYVPNMLGIIPYAGI 364
Cdd:pfam00153   1 SELSFLASLLAGGIAGAIAVTVTYPLDVVKTRLQVqggSGKSKGRGILDCFKKIYKEEGIRGLYKGLLPNLLRVAPAAAI 80

                          90
                  ....*....|....*.
gi 1622870727 365 DLAVYETLKNaWLQRY 380
Cdd:pfam00153  81 YFGTYETLKR-LLLKK 95

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1622870727  53 QKIVQAGDKDLDGQLDFEEFVH---YLQDhekkLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKR 125
Cdd:cd16185    39 EKLIRMFDRDGNGTIDFEEFAAlhqFLSN----MQNGFEQRDTSRSGRLDANEVHEALAASGFQLDPPAFQALFRK 110

calmodulin; Provisional

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1622870727  60 DKDLDGQLDFEEFVHYLQ------DHEKKLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILK 124
Cdd:PTZ00184   57 DADGNGTIDFPEFLTLMArkmkdtDSEEEIKEAFKVFDRDGNGFISAAELRHVMTNLGEKLTDEEVDEMIR 127

Mitochondrial carrier protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 288 ETLRIHERLVAGSLAGAIAQSSIYPMEVLKTRMAL---RKTGQYSGMLDCARRILAREGVAAFYKGYVPNMLGIIPYAGI 364
Cdd:pfam00153   1 SELSFLASLLAGGIAGAIAVTVTYPLDVVKTRLQVqggSGKSKGRGILDCFKKIYKEEGIRGLYKGLLPNLLRVAPAAAI 80

                          90
                  ....*....|....*.
gi 1622870727 365 DLAVYETLKNaWLQRY 380
Cdd:pfam00153  81 YFGTYETLKR-LLLKK 95

Mitochondrial carrier protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 386 DPGVFVLLACGTMSSTCGQLASYPLALVRTRMQAQASIEGAPEVTMSSLFKQILRTEGAFGLYRGLAPNFMKVIPAVSIS 465
Cdd:pfam00153   2 ELSFLASLLAGGIAGAIAVTVTYPLDVVKTRLQVQGGSGKSKGRGILDCFKKIYKEEGIRGLYKGLLPNLLRVAPAAAIY 81

                          90
                  ....*....|..
gi 1622870727 466 YVVYENLKITLG 477
Cdd:pfam00153  82 FGTYETLKRLLL 93

ADP/ATP transporter on adenylate translocase; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 202 LVAGGGAGAVSRTCTAPLD----RLKVLMQVHASRSNNmGIIGGFTQMIREGGARSLWRGNGINVLKIAPESAIKFMAYE 277
Cdd:PTZ00169  117 ILSGGLAGASSLLIVYPLDfartRLASDIGKGGDREFT-GLFDCLMKISKQTGFLSLYQGFGVSVQGIIVYRGAYFGLYD 195

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 278 QIKRLV-GSDQETLRIHERLVAGS---LAGAIAqssiYPMEVLKTRMAL---RKTG---QYSGMLDCARRILAREGVAAF 347
Cdd:PTZ00169  196 SAKALLfGNDKNTNILYKWAVAQTvtiLAGLIS----YPFDTVRRRMMMmsgRKAKseiQYTGTLDCWKKILKNEGLGGF 271

                  ....*....
gi 1622870727 348 YKGYVPNML 356
Cdd:PTZ00169  272 FKGAWANVL 280

EF-hand domain pair;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1622870727  80 EKKLRLVFKSLDKKNDGRIDAQEIMQSLR--DLGVKISEQQAEKILKrirtghfwgpvtYMDKNGTMTIDWNE 150
Cdd:pfam13499   1 EEKLKEAFKLLDSDGDGYLDVEELKKLLRklEEGEPLSDEEVEELFK------------EFDLDKDGRISFEE 61

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 1622870727  53 QKIVQAGDKDLDGQLDFEEFvHYLQDHEKKLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKRirtghfw 132
Cdd:cd15897    43 RSMIAMMDRDHSGKLNFSEF-KGLWNYIKAWQEIFRTYDTDGSGTIDSNELRQALSGAGYRLSEQTYDIIIRR------- 114

                          90
                  ....*....|....*
gi 1622870727 133 gpvtYMDKNGTMTID 147
Cdd:cd15897   115 ----YDRGRGNIDFD 125

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 1622870727  55 IVQAGDKDLDGQLDFEEFvHYLQDHEKKLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKRirtghfwgp 134
Cdd:cd16188    48 MVAVMDSDTTGKLGFEEF-KYLWNNIKKWQGIYKQFDTDRSGTIGSQELPGAFEAAGFHLNEQLYQMIIRR--------- 117

                          90
                  ....*....|...
gi 1622870727 135 vtYMDKNGTMTID 147
Cdd:cd16188   118 --YSDEDGNMDFD 128

mitochondrial carrier protein; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 296 LVAGSLAGAIAQSSIYPMEVLKTRMALRKTGQYSgmldcarrilareGVAAFYKGYVPNMLGIIPYAGIDLAVYEtLKNA 375
Cdd:PTZ00168    7 LVTGALSGVIVDAVLYPIDSIKTNIQAKKSFSFS-------------DIKKLYSGILPTLVGTVPASAFFYCFYE-LSKK 72

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 376 WLQRYAVNSADPGVFvlLACGTMSSTCGQLASYPLALVRTRMQAQASIegapevtmsSLFKQILRTEGAFGLYRGLAPNF 455
Cdd:PTZ00168   73 LLTEYRENISKTNLY--LISTSIAEITACIVRLPFEIVKQNMQVSGNI---------SVLKTIYEITQREGLPSFLGKSY 141

                         170       180
                  ....*....|....*....|..
gi 1622870727 456 M----KVIPAVSISYVVYENLK 473
Cdd:PTZ00168  142 FvmivREIPFDCIQYFLWETLK 163

mitochondrial carrier protein; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 200 RHLVAGGGAGAVSRTCTAPLDRLKVLMQVHASRSnnmgiiggFTQMireggaRSLWRGNGINVLKIAPESAIKFMAYEQI 279
Cdd:PTZ00168    5 HNLVTGALSGVIVDAVLYPIDSIKTNIQAKKSFS--------FSDI------KKLYSGILPTLVGTVPASAFFYCFYELS 70

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 280 KRLVGSDQETL-RIHERLVAGSLAGAIAQSSIYPMEVLKTRMalrktgQYSG---MLDCARRILAREGVAAFY-KGYVPN 354
Cdd:PTZ00168   71 KKLLTEYRENIsKTNLYLISTSIAEITACIVRLPFEIVKQNM------QVSGnisVLKTIYEITQREGLPSFLgKSYFVM 144

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727 355 MLGIIPYAGIDLAVYETLKNAWLQRYAVNSADPGVFVLLACGTMSSTCGQLASYPLALVRTR--MQAQASIEGAPEVTms 432
Cdd:PTZ00168  145 IVREIPFDCIQYFLWETLKEKAKKDFGKFSKKYPSITSAICGGLAGGIAGFLTTPVDVIKSRqiIYGKSYIETVTEIA-- 222

                         250
                  ....*....|....*...
gi 1622870727 433 slfkqilrTEGAFGLYRG 450
Cdd:PTZ00168  223 --------EEGYLTFYKG 232

EF-hand, calcium binding motif, found in peflin and similar proteins; Peflin, also termed penta-EF hand (PEF) protein with a long N-terminal hydrophobic domain, or penta-EF hand domain-containing protein 1, 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+. In lower vertebrates, peflin may interact with transient receptor potential N (TRPN1), suggesting a potential role of peflin in fast transducer channel adaptation.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1622870727  60 DKDLDGQLDFEEFV---HYLQdhekKLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKR 125
Cdd:cd16184    47 DKDKSGTIDIYEFQalwNYIQ----QWKQVFQQFDRDRSGSIDENELHQALSQMGYRLSPQFVQFLVSK 111

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 1622870727  60 DKDLDGQLDFEEFVHYLQDHEKKLRLV-----FKS-LDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKRirtghfwg 133
Cdd:cd16227   169 DKDNDGFISFQEFLGDRAGHEDKEWLLvekdrFDEdYDKDGDGKLDGEEILSWLVPDNEEIAEEEVDHLFAS-------- 240

                          90
                  ....*....|....
gi 1622870727 134 pvTYMDKNGTMTID 147
Cdd:cd16227   241 --ADDDHDDRLSFD 252

Penta-EF hand, calcium binding motifs, found in PEF calpain family; The PEF calpain family belongs to the second group of penta-EF hand (PEF) proteins. It includes classical (also called conventional or typical) calpain (referring to a calcium-dependent papain-like enzymes, EC 3.4.22.17) large catalytic subunits (CAPN1, 2, 3, 8, 9, 11, 12, 13, 14) and two calpain small subunits (CAPNS1 and CAPNS2), which are largely confined to animals (metazoans). These PEF-containing are nonlysosomal intracellular calcium-activated intracellular cysteine proteases that play important roles in the degradation or functional modulation in a variety of substrates in response to calcium signalling. The classical mu- and m-calpains are heterodimers consisting of homologous but a distinct (large) L-subunit/chain (CAPN1 or CAPN2) and a common (small) S-subunit/chain (CAPNS1 or CAPNS2). These L-subunits (CAPN1 and CAPN2) and S-subunit CAPNS1 are ubiquitously found in all tissues. Other calpains likely consist of an isolated L-subunit/chain alone. Many of them, such as CAPNS2, CAPN3 (in skeletal muscle, or lens), CAPN8 (in stomach), CAPN9 (in digestive tracts), CAPN11 (in testis), CAPN12 (in follicles), are tissue-specific and have specific functions in distinct organs. The L-subunits of similar structure (called CALPA and B) also have been found in Drosophila melanogaster. The S-subunit seems to have a chaperone-like function for proper folding of the L-subunit. The catalytic L-subunits 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 S-subunits only have the PEF domain following an N-terminal Gly-rich hydrophobic domain. The calpains undergo a rearrangement of the protein backbone upon Ca2+-binding.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1622870727  29 ELKSIFK---LSVFIPSQEFS--TYRQwkqkIVQAGDKDLDGQLDFEEFvHYLQDHEKKLRLVFKSLDKKNDGRIDAQEI 103
Cdd:cd16182    20 ELQKLLNaslLKDMPKFDGFSleTCRS----LIALMDTNGSGRLDLEEF-KTLWSDLKKWQAIFKKFDTDRSGTLSSYEL 94

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 1622870727 104 MQSLRDLGVKISEQQAEKILKRirtghfwgpvtYMDKNGTMTID 147
Cdd:cd16182    95 RKALESAGFHLSNKVLQALVLR-----------YADSTGRITFE 127

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 1622870727  82 KLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKrirtghfwgpvtYMDKNGTMTIDWNEWRD-YHLLHpv 160
Cdd:cd15898     1 WLRRQWIKADKDGDGKLSLKEIKKLLKRLNIRVSEKELKKLFK------------EVDTNGDGTLTFDEFEElYKSLT-- 66

                          90
                  ....*....|.
gi 1622870727 161 eNIPEIILYWK 171
Cdd:cd15898    67 -ERPELEPIFK 76

Penta-EF hand, calcium binding motifs, found in sorcin, grancalcin, and similar proteins; The family corresponds to the second group of penta-EF hand (PEF) proteins that includes sorcin, grancalcin, and similar proteins. 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. It 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. Grancalcin (GCA) is a cytosolic Ca2+-binding protein specifically expressed in neutrophils and monocytes/macrophages. It 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. In contrast with sorcin, GCA binds two Ca2+ ions through its EF1 and EF3 hands.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1622870727  60 DKDLDGQLDFEEFvhylqdheKKL-------RLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKRIRTGHF 131
Cdd:cd16181    50 DRDHSGKMGFNEF--------KELwaalnqwKTTFMQYDRDRSGTVEPQELQQAIRSFGYNLSPQALNVIVKRYSKNGR 120

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
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1622870727  60 DKDLDGQLDFEEFVHYLQDhekkLRL---VFKSLDKKNDGRIDAQEIMQSLRDLGVKIS 115
Cdd:cd16196    51 DVDRSGKLGFEEFKKLWED----LRSwkrVFKLFDTDGSGSFSSFELRNALNSAGFRLS 105

EF-hand motif found in phosphoinositide phospholipase C delta 3 (PI-PLC-delta3); PI-PLC-delta3, also termed 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase delta-3 (PLCD3), phospholipase C-delta-3 (PLC-delta-3), is expressed abundantly in brain, skeletal muscle and heart. PI-PLC-delta3 gene expression is down-regulation by cAMP and calcium. PI-PLC-delta3 acts as anchoring of myosin VI on plasma membrane, and further modulates Myosin IV expression and microvilli formation in enterocytes. It negatively regulates RhoA expression, inhibits RhoA/Rho kinase signaling, and plays an essential role in normal neuronal migration by promoting neuronal outgrowth in the developing brain. Moreover, PI-PLC-delta3 is essential in trophoblasts for placental development. Simultaneous loss of PI-PLC-delta3 may cause placental vascular defects, leading to embryonic lethality. PI-PLC-delta3 contains 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 C-terminal C2 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. In addition, PI-PLC-delta3 possesses a classical leucine-rich nuclear export sequence (NES) located in the EF hand motifs, which may be responsible transporting PI-PLC-delta3 from the cell nucleus.

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gi 1622870727  51 WKQKIVQAGDKDLDGQLDFEEFVHYLQD-----HEKKLRLVFKSLDKKNDGRIDAQEIMQSLRDL 110
Cdd:cd16218     1 WIHEYLRRADLNKDGKMSFEEIKDLLQMinidlNEQYAYQLFKECDRSNDDRLEEHEIEEFCRRL 65

EF-hand motif found in phosphoinositide phospholipase C delta (PI-PLC-delta); PI-PLC-delta isozymes represent a class of metazoan PI-PLCs that are some of the most sensitive to calcium among all PLCs. Their activation is modulated by intracellular calcium ion concentration, phospholipids, polyamines, and other proteins, such as RhoAGAP. Like other PI-PLC isozymes, PI-PLC-delta isozymes contain 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 C-terminal C2 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. There are three PI-PLC-delta isozymes (1, 3 and 4). PI-PLC-delta1 is relatively well characterized. It is activated by high calcium levels generated by other PI-PLC family members, and therefore functions as a calcium amplifier within the cell. Different PI-PLC-delta isozymes have different tissue distribution and different subcellular locations. PI-PLC-delta1 is mostly a cytoplasmic protein, PI-PLC-delta3 is located in the membrane, and PI-PLC-delta4 is predominantly detected in the cell nucleus. PI-PLC-delta isozymes is evolutionarily conserved even in non-mammalian species, such as yeast, slime molds and plants.

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gi 1622870727  83 LRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKR 125
Cdd:cd16202     2 LKDQFRKADKNGDGKLSFKECKKLLKKLNVKVDKDYAKKLFQE 44