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

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1386635368  38 EKIVQAGDKDLDGQLDFEEFVHY-----LQDHEKKLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVkiSEQQAEKILKRIr 112
Cdd:COG5126    36 ATLFSEADTDGDGRISREEFVAGmeslfEATVEPFARAAFDLLDTDGDGKISADEFRRLLTALGV--SEEEADELFARL- 112

                          90       100       110
                  ....*....|....*....|....*....|..
gi 1386635368 113 tghfwgpvtymDKNGTMTIDWNE----WRDYH 140
Cdd:COG5126   113 -----------DTDGDGKISFEEfvaaVRDYY 133

Mitochondrial carrier protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1386635368 273 ETLRIHERLVAGSLAGAIAQSSIYPMEVLKTRMAL---RKTGQYSGMLDCARRILAKEGVAAFYKGYIPNMLGIIPYAGI 349
Cdd:pfam00153   1 SELSFLASLLAGGIAGAIAVTVTYPLDVVKTRLQVqggSGKSKGRGILDCFKKIYKEEGIRGLYKGLLPNLLRVAPAAAI 80

                          90
                  ....*....|....*.
gi 1386635368 350 DLAVYETLKNtWLQRY 365
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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1386635368  31 VFDLPPAEKIVQAGDKDLDGQLDFEEFVH---YLQDhekkLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKI 107
Cdd:cd16185    32 LFSLATAEKLIRMFDRDGNGTIDFEEFAAlhqFLSN----MQNGFEQRDTSRSGRLDANEVHEALAASGFQLDPPAFQAL 107

                  ...
gi 1386635368 108 LKR 110
Cdd:cd16185   108 FRK 110

calmodulin; Provisional

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1386635368  45 DKDLDGQLDFEEFVHYLQ------DHEKKLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILK 109
Cdd:PTZ00184   57 DADGNGTIDFPEFLTLMArkmkdtDSEEEIKEAFKVFDRDGNGFISAAELRHVMTNLGEKLTDEEVDEMIR 127

Mitochondrial carrier protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1386635368 273 ETLRIHERLVAGSLAGAIAQSSIYPMEVLKTRMAL---RKTGQYSGMLDCARRILAKEGVAAFYKGYIPNMLGIIPYAGI 349
Cdd:pfam00153   1 SELSFLASLLAGGIAGAIAVTVTYPLDVVKTRLQVqggSGKSKGRGILDCFKKIYKEEGIRGLYKGLLPNLLRVAPAAAI 80

                          90
                  ....*....|....*.
gi 1386635368 350 DLAVYETLKNtWLQRY 365
Cdd:pfam00153  81 YFGTYETLKR-LLLKK 95

Mitochondrial carrier protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1386635368 371 DPGVFVLLACGTISSTCGQLASYPLALVRTRMQAQASIEGAPEVTMSSLFKQILRTEGAFGLYRGLAPNFMKVIPAVSIS 450
Cdd:pfam00153   2 ELSFLASLLAGGIAGAIAVTVTYPLDVVKTRLQVQGGSGKSKGRGILDCFKKIYKEEGIRGLYKGLLPNLLRVAPAAAIY 81

                          90
                  ....*....|..
gi 1386635368 451 YVVYENLKITLG 462
Cdd:pfam00153  82 FGTYETLKRLLL 93

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 1386635368  31 VFDLPPAEKIVQAGDKDLDGQLDFEEFVH---YLQDhekkLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKI 107
Cdd:cd16185    32 LFSLATAEKLIRMFDRDGNGTIDFEEFAAlhqFLSN----MQNGFEQRDTSRSGRLDANEVHEALAASGFQLDPPAFQAL 107

                  ...
gi 1386635368 108 LKR 110
Cdd:cd16185   108 FRK 110

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 1386635368  32 FDLPPAEKIVQAGDKDLDGQLDFEEFvHYLQDHEKKLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKRi 111
Cdd:cd15897    37 FSLETCRSMIAMMDRDHSGKLNFSEF-KGLWNYIKAWQEIFRTYDTDGSGTIDSNELRQALSGAGYRLSEQTYDIIIRR- 114

                          90       100
                  ....*....|....*....|.
gi 1386635368 112 rtghfwgpvtYMDKNGTMTID 132
Cdd:cd15897   115 ----------YDRGRGNIDFD 125

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        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1386635368  67 KLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKRirtghfwgpvtyMDKNGTMTIDWNEWRD 138
Cdd:cd00051     1 ELREAFRLFDKDGDGTISADELKAALKSLGEGLSEEEIDEMIRE------------VDKDGDGKIDFEEFLE 60

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

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1386635368  37 AEKIVQAGDKDLDGQLDFEEFVHYLQDH---EKKLRLVFKSLDKKNDGRIDAQEIMQSLRD 94
Cdd:COG5126    71 ARAAFDLLDTDGDGKISADEFRRLLTALgvsEEEADELFARLDTDGDGKISFEEFVAAVRD 131

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1386635368  45 DKDLDGQLDFEEFV---HYLQDHEKklrlVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKR 110
Cdd:cd16180    47 DRDRSGTINFDEFVglwKYIQDWRR----LFRRFDRDRSGSIDFNELQNALSSFGYRLSPQFVQLLVRK 111

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 1386635368  45 DKDLDGQLDFEEFVHYLQDH-----EKKLRLVFKSLDKKNDGRIDAQEIMQ 90
Cdd:cd00051    10 DKDGDGTISADELKAALKSLgeglsEEEIDEMIREVDKDGDGKIDFEEFLE 60

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 1386635368  37 AEKIVQAGDKDLDGQLDFEEFVH-YLQDHEKK-LRLVFKSLDKKNDGRIDAQEIMQSLRD-LGVKISEQQAEKILKRirt 113
Cdd:cd15898    38 LKKLFKEVDTNGDGTLTFDEFEElYKSLTERPeLEPIFKKYAGTNRDYMTLEEFIRFLREeQGENVSEEECEELIEK--- 114

                          90
                  ....*....|....*....
gi 1386635368 114 ghfwgpVTYMDKNGTMTID 132
Cdd:cd15898   115 ------YEPERENRQLSFE 127

EF-hand domain pair;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1386635368  45 DKDLDGQLDFEEFVHYLQDH-------EKKLRLVFKSLDKKNDGRIDAQEIMQ 90
Cdd:pfam13499  12 DSDGDGYLDVEELKKLLRKLeegeplsDEEVEELFKEFDLDKDGRISFEEFLE 64

EF-hand, calcium binding motif, found in apoptosis-linked gene 2 protein (ALG-2) and similar proteins; ALG-2, also termed programmed cell death protein 6 (PDCD6), or probable calcium-binding protein ALG-2, is one of the prototypic members of the penta EF-hand protein family. It is a widely expressed calcium-binding modulator protein associated with cell proliferation and death, as well as cell survival. ALG-2 acts as a pro-apoptotic factor participating in T cell receptor-, Fas-, and glucocorticoid-induced programmed cell death, and also serves as a useful molecular marker for the prognosis of cancers. Moreover, ALG-2 functions as a calcium ion sensor at endoplasmic reticulum (ER) exit sites, and modulates ER-stress-stimulated cell death and neuronal apoptosis during organ formation. Furthermore, ALG-2 can mediate the pro-apoptotic activity of cisplatin or tumor necrosis factor alpha (TNFalpha) through the down-regulation of nuclear factor-kappaB (NF-kappaB) expression. It also inhibits angiogenesis through PI3K/mTOR/p70S6K pathway by interacting of vascular endothelial growth factor receptor-2 (VEGFR-2). In addition, nuclear ALG-2 may participate in the post-transcriptional regulation of Inositol Trisphosphate Receptor Type 1 (IP3R1) pre-mRNA at least in part by interacting with CHERP (Ca2+ homeostasis endoplasmic reticulum protein) calcium-dependently. ALG-2 contains five serially repeated EF-hand motifs and interacts with various proteins, including ALG-2-interacting protein X (Alix), Fas, annexin XI, death-associated protein kinase 1 (DAPk1), Tumor susceptibility gene 101 (TSG101), Sec31A, phospholipid scramblase 3 (PLSCR3), the P-body component PATL1, and endosomal sorting complex required for transport (ESCRT)-III-related protein IST1, in a calcium-dependent manner. 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.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1386635368  45 DKDLDGQLDFEEFV---HYLQDHEKklrlVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKRI-RTGH 115
Cdd:cd16183    47 DRDNSGTINFQEFAalwKYITDWQN----CFRSFDRDNSGNIDKNELKQALTSFGYRLSDQFYDILVRKFdRQGR 117

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 1386635368  67 KLRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKrirtghfwgpvtYMDKNGTMTIDWNEWRD-YHLLHpv 145
Cdd:cd15898     1 WLRRQWIKADKDGDGKLSLKEIKKLLKRLNIRVSEKELKKLFK------------EVDTNGDGTLTFDEFEElYKSLT-- 66

                          90
                  ....*....|.
gi 1386635368 146 eNIPEIILYWK 156
Cdd:cd15898    67 -ERPELEPIFK 76

EF-hand domain;

                          10        20        30
                  ....*....|....*....|....*....|
gi 1386635368  67 KLRLVFKSLDKKNDGRIDAQEIMQSLRDLG 96
Cdd:pfam13405   1 ELREAFKLFDKDGDGKISLEELRKALRSLG 30

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 1386635368  45 DKDLDGQLDFEEFvhylqdheKKL-------RLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKRIRTGHF 116
Cdd:cd16181    50 DRDHSGKMGFNEF--------KELwaalnqwKTTFMQYDRDRSGTVEPQELQQAIRSFGYNLSPQALNVIVKRYSKNGR 120

centrin; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1386635368   7 LFPSPGKVYLDI---IFALQK---EQKRSQVFdlppaeKIVQAGDKDLDGQLDFEEFVHYL------QDHEKKLRLVFKS 74
Cdd:PTZ00183   25 LFDTDGSGTIDPkelKVAMRSlgfEPKKEEIK------QMIADVDKDGSGKIDFEEFLDIMtkklgeRDPREEILKAFRL 98

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1386635368  75 LDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKRirtghfwgpvtyMDKNGTMTIDWNE 135
Cdd:PTZ00183   99 FDDDKTGKISLKNLKRVAKELGETITDEELQEMIDE------------ADRNGDGEISEEE 147

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1386635368  42 QAGDKDLDGQLDFEEFVHYLQD-----HEKKLRLVFKSLDKKNDGRIDAQEIMQSLRDL 95
Cdd:cd16202     7 RKADKNGDGKLSFKECKKLLKKlnvkvDKDYAKKLFQEADTSGEDVLDEEEFVQFYNRL 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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1386635368  68 LRLVFKSLDKKNDGRIDAQEIMQSLRDLGVKISEQQAEKILKR 110
Cdd:cd16202     2 LKDQFRKADKNGDGKLSFKECKKLLKKLNVKVDKDYAKKLFQE 44

EF-hand motif found in Saccharomyces cerevisiae phospholipase C-1 (ScPlc1p) and similar proteins; This family represents a group of putative phosphoinositide-specific phospholipase C (PI-PLC, EC 3.1.4.11) encoded by PLC1 genes from yeasts, which are homologs of the delta isoforms of mammalian PI-PLC in terms of overall sequence similarity and domain organization. Mammalian PI-PLC is a signaling enzyme that hydrolyzes 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 then phosphorylates other molecules, leading to altered cellular activity. Calcium is required for the catalysis. The prototype of this family is protein Plc1p (also termed 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase 1) encoded by PLC1 genes from Saccharomyces cerevisiae. ScPlc1p contains both highly conserved X- and Y- regions of PLC catalytic core domain, as well as a presumptive EF-hand like calcium binding motif. Experiments show that ScPlc1p displays calcium dependent catalytic properties with high similarity to those of the mammalian PLCs, and plays multiple roles in modulating the membrane/protein interactions in filamentation control. CaPlc1p encoded by CAPLC1 from the closely related yeast Candida albicans, an orthologue of S. cerevisiae Plc1p, is also included in this group. Like SCPlc1p, CaPlc1p has conserved presumptive catalytic domain, shows PLC activity when expressed in E. coli, and is involved in multiple cellular processes. There are two other gene copies of CAPLC1 in C. albicans, CAPLC2 (also named as PIPLC) and CAPLC3. Experiments show CaPlc1p is the only enzyme in C. albicans which functions as PLC. The biological functions of CAPLC2 and CAPLC3 gene products must be clearly different from CaPlc1p, but their exact roles remain unclear. Moreover, CAPLC2 and CAPLC3 gene products are more similar to extracellular bacterial PI-PLC than to the eukaryotic PI-PLC, and they are not included in this subfamily.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1386635368  45 DKDLDGQLDFEEFVHYLqdheKKLR------LVFKSLDKKNDGRIDAQEIMQSLRDL-GVKISEQQAEKILKRIRTGHFW 117
Cdd:cd16207    48 DTDKKGYLNFEEFQEFV----KLLKrrkdikAIFKQLTKPGSDGLTLEEFLKFLRDVqKEDVDRETWEKIFEKFARRIDD 123

                          90
                  ....*....|
gi 1386635368 118 GPVTYMDKNG 127
Cdd:cd16207   124 SDSLTMTLEG 133