C2 domain found in Rab11-family interacting proteins (FIP) class I; Rab GTPases recruit various effector proteins to organelles and vesicles. Rab11-family interacting proteins (FIPs) are involved in mediating the role of Rab11. FIPs can be divided into three classes: class I FIPs (Rip11a, Rip11b, RCP, and FIP2) which contain a C2 domain after N-terminus of the protein, class II FIPs (FIP3 and FIP4) which contain two EF-hands and a proline rich region, and class III FIPs (FIP1) which exhibits no homology to known protein domains. All FIP proteins contain a highly conserved, 20-amino acid motif at the C-terminus of the protein, known as Rab11/25 binding domain (RBD). Class I FIPs are thought to bind to endocytic membranes via their C2 domain, which interacts directly with phospholipids. Class II FIPs do not have any membrane binding domains leaving much to speculate about the mechanism involving FIP3 and FIP4 interactions with endocytic membranes. The members in this CD are class I FIPs. The exact function of the Rab11 and FIP interaction is unknown, but there is speculation that it involves the role of forming a targeting complex that recruits a group of proteins involved in membrane transport to organelles. The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKPKGKSGTNDTYTIIQLGKEKYSTSVAEKTLEPVWKEEASFELPGLLIqGSPEKYILFLIVMHRSLVGL 94
Cdd:cd08682   1 VQVTVLQARGLLCKGKSGTNDAYVIIQLGKEKYSTSVKEKTTSPVWKEECSFELPGLLS-GNGNRATLQLTVMHRNLLGL 79

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*..
gi 7662394   95 DKFLGQVAINLNDIFEDKQRRKTEWFRLESKQGKRIKNRGEIKVNIQ 141
Cdd:cd08682  80 DKFLGQVSIPLNDLDEDKGRRRTRWFKLESKPGKDDKERGEIEVDIQ 126

C2 domain found in Rab11-family interacting proteins (FIP) class I; Rab GTPases recruit various effector proteins to organelles and vesicles. Rab11-family interacting proteins (FIPs) are involved in mediating the role of Rab11. FIPs can be divided into three classes: class I FIPs (Rip11a, Rip11b, RCP, and FIP2) which contain a C2 domain after N-terminus of the protein, class II FIPs (FIP3 and FIP4) which contain two EF-hands and a proline rich region, and class III FIPs (FIP1) which exhibits no homology to known protein domains. All FIP proteins contain a highly conserved, 20-amino acid motif at the C-terminus of the protein, known as Rab11/25 binding domain (RBD). Class I FIPs are thought to bind to endocytic membranes via their C2 domain, which interacts directly with phospholipids. Class II FIPs do not have any membrane binding domains leaving much to speculate about the mechanism involving FIP3 and FIP4 interactions with endocytic membranes. The members in this CD are class I FIPs. The exact function of the Rab11 and FIP interaction is unknown, but there is speculation that it involves the role of forming a targeting complex that recruits a group of proteins involved in membrane transport to organelles. The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKPKGKSGTNDTYTIIQLGKEKYSTSVAEKTLEPVWKEEASFELPGLLIqGSPEKYILFLIVMHRSLVGL 94
Cdd:cd08682   1 VQVTVLQARGLLCKGKSGTNDAYVIIQLGKEKYSTSVKEKTTSPVWKEECSFELPGLLS-GNGNRATLQLTVMHRNLLGL 79

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*..
gi 7662394   95 DKFLGQVAINLNDIFEDKQRRKTEWFRLESKQGKRIKNRGEIKVNIQ 141
Cdd:cd08682  80 DKFLGQVSIPLNDLDEDKGRRRTRWFKLESKPGKDDKERGEIEVDIQ 126

Protein kinase C conserved region 2 (CalB); Ca2+-binding motif present in phospholipases, protein kinases C, and synaptotagmins (among others). Some do not appear to contain Ca2+-binding sites. Particular C2s appear to bind phospholipids, inositol polyphosphates, and intracellular proteins. Unusual occurrence in perforin. Synaptotagmin and PLC C2s are permuted in sequence with respect to N- and C-terminal beta strands. SMART detects C2 domains using one or both of two profiles.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394      17 VTVLQAKDLKPKGKSGTNDTYTIIQLG---KEKYSTSVAEKTLEPVWKEEASFELPglliqgSPEKYILFLIVMHRSLVG 93
Cdd:smart00239   4 VKIISARNLPPKDKGGKSDPYVKVSLDgdpKEKKKTKVVKNTLNPVWNETFEFEVP------PPELAELEIEVYDKDRFG 77

                           90       100
                   ....*....|....*....|...
gi 7662394      94 LDKFLGQVAINLNDIFEDKQRRK 116
Cdd:smart00239  78 RDDFIGQVTIPLSDLLLGGRHEK 100

Ca2+-dependent lipid-binding protein, contains C2 domain [General function prediction only];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394    17 VTVLQAKDLKPKGKSGTNDTY-TIIQLGKEKYSTSVAEKTLEPVWKEE--ASFELPgllIQgspekyILFLIVMHRSLVG 93
Cdd:COG5038  715 VSVRKANDLRNEIPGGKSDPYaTVLVNNLVKYRTIYGSSTLNPIWNEIlyVPVTSK---NQ------RLTLECMDYEESG 785

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394    94 LDKFLGQVAINLNDIF---EDKQRRKTEWFRLESKQ--GKRIKNRGEIKVNIQFMRNNMTASMFDLSMKDKTRSPFAKLK 168
Cdd:COG5038  786 DDRNLGEVNINVSNVSkkdEDSALMETIDGAEETGKlsLTGKKVKGTITYKCRFYPAVIVLSLEEVRYVDKVSSEKRKSE 865

                        170
                 ....*....|....*...
gi 7662394   169 dkmkgRKNDGTFSDTSSA 186
Cdd:COG5038  866 -----KRKSALDEKTISL 878

C2 domain found in Rab11-family interacting proteins (FIP) class I; Rab GTPases recruit various effector proteins to organelles and vesicles. Rab11-family interacting proteins (FIPs) are involved in mediating the role of Rab11. FIPs can be divided into three classes: class I FIPs (Rip11a, Rip11b, RCP, and FIP2) which contain a C2 domain after N-terminus of the protein, class II FIPs (FIP3 and FIP4) which contain two EF-hands and a proline rich region, and class III FIPs (FIP1) which exhibits no homology to known protein domains. All FIP proteins contain a highly conserved, 20-amino acid motif at the C-terminus of the protein, known as Rab11/25 binding domain (RBD). Class I FIPs are thought to bind to endocytic membranes via their C2 domain, which interacts directly with phospholipids. Class II FIPs do not have any membrane binding domains leaving much to speculate about the mechanism involving FIP3 and FIP4 interactions with endocytic membranes. The members in this CD are class I FIPs. The exact function of the Rab11 and FIP interaction is unknown, but there is speculation that it involves the role of forming a targeting complex that recruits a group of proteins involved in membrane transport to organelles. The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKPKGKSGTNDTYTIIQLGKEKYSTSVAEKTLEPVWKEEASFELPGLLIqGSPEKYILFLIVMHRSLVGL 94
Cdd:cd08682   1 VQVTVLQARGLLCKGKSGTNDAYVIIQLGKEKYSTSVKEKTTSPVWKEECSFELPGLLS-GNGNRATLQLTVMHRNLLGL 79

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*..
gi 7662394   95 DKFLGQVAINLNDIFEDKQRRKTEWFRLESKQGKRIKNRGEIKVNIQ 141
Cdd:cd08682  80 DKFLGQVSIPLNDLDEDKGRRRTRWFKLESKPGKDDKERGEIEVDIQ 126

C2 domain; The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKPKGKSGTNDTYTIIQLG-KEKYSTSVAEKTLEPVWKEEASFELPglliqgSPEKYILFLIVMHRSLVG 93
Cdd:cd00030   1 LRVTVIEARNLPAKDLNGKSDPYVKVSLGgKQKFKTKVVKNTLNPVWNETFEFPVL------DPESDTLTVEVWDKDRFS 74

                        90       100
                ....*....|....*....|....*....
gi 7662394   94 LDKFLGQVAINLNDIFEDKQRRkTEWFRL 122
Cdd:cd00030  75 KDDFLGEVEIPLSELLDSGKEG-ELWLPL 102

C2 domain first repeat present in Synaptotagmin-like proteins; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   17 VTVLQAKDLKPK--GKSGTNDTYTIIQLGKEKYSTSVAEKTLEPVWKEeaSFELPGLLIQGSpekyILFLIVMHRSLVGL 94
Cdd:cd04024   5 VHVVEAKDLAAKdrSGKGKSDPYAILSVGAQRFKTQTIPNTLNPKWNY--WCEFPIFSAQNQ----LLKLILWDKDRFAG 78

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*.
gi 7662394   95 DKFLGQVAINLNDIFED-KQRRKTEWFRLESKQ-GKRIKNRGEIKV 138
Cdd:cd04024  79 KDYLGEFDIALEEVFADgKTGQSDKWITLKSTRpGKTSVVSGEIHL 124

C2 domain second repeat present in Synaptotagmin; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. There are several classes of Synaptotagmins. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   14 HVQVTVLQAKDLKPKGKSGTNDTY---TIIQLGKE--KYSTSVAEKTLEPVWKEEASFELPGLLIQGSpekyILFLIVMH 88
Cdd:cd00276  15 RLTVVVLKARNLPPSDGKGLSDPYvkvSLLQGGKKlkKKKTSVKKGTLNPVFNEAFSFDVPAEQLEEV----SLVITVVD 90

                        90
                ....*....|....*
gi 7662394   89 RSLVGLDKFLGQVAI 103
Cdd:cd00276  91 KDSVGRNEVIGQVVL 105

C2 domain first and third repeat in Synaptotagmin-like proteins; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains either the first or third repeat in Synaptotagmin-like proteins with a type-I topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKPK------GKSGTNDTYTIIQLGKEKYSTSVAEKTLEPVWKE--EA-SFELPGLLIQgspekyilflI 85
Cdd:cd08391   3 LRIHVIEAQDLVAKdkfvggLVKGKSDPYVIVRVGAQTFKSKVIKENLNPKWNEvyEAvVDEVPGQELE----------I 72

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*...
gi 7662394   86 VMHRSLVGLDKFLGQVAINLNDIFedKQRRKTEWFRLESKQGKRIKNR 133
Cdd:cd08391  73 ELFDEDPDKDDFLGRLSIDLGSVE--KKGFIDEWLPLEDVKSGRLHLK 118

C2A domain first repeat present in Synaptotagmins 1, 5, 6, 9, and 10; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 1, a member of class 1 synaptotagmins, is located in the brain and endocranium and localized to the synaptic vesicles and secretory granules. It functions as a Ca2+ sensor for fast exocytosis as do synaptotagmins 5, 6, and 10. It is distinguished from the other synaptotagmins by having an N-glycosylated N-terminus. Synaptotagmins 5, 6, and 10, members of class 3 synaptotagmins, are located primarily in the brain and localized to the active zone and plasma membrane. They is distinguished from the other synaptotagmins by having disulfide bonds at its N-terminus. Synaptotagmin 6 also regulates the acrosome reaction, a unique Ca2+-regulated exocytosis, in sperm. Synaptotagmin 9, a class 5 synaptotagmins, is located in the brain and localized to the synaptic vesicles. It is thought to be a Ca2+-sensor for dense-core vesicle exocytosis. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   17 VTVLQAKDLKPKGKSGTNDTYTIIQL---GKEKYSTSVAEKTLEPVWKEEASFELPGLLIQGspeKYILFlivmhrSLVG 93
Cdd:cd08385  20 VGIIQAADLPAMDMGGTSDPYVKVYLlpdKKKKFETKVHRKTLNPVFNETFTFKVPYSELGN---KTLVF------SVYD 90

                        90       100       110
                ....*....|....*....|....*....|....*.
gi 7662394   94 LDKF-----LGQVAINLNDifEDKQRRKTEWFRLES 124
Cdd:cd08385  91 FDRFskhdlIGEVRVPLLT--VDLGHVTEEWRDLES 124

C2 domain fifth repeat in Ferlin; Ferlins are involved in vesicle fusion events. Ferlins and other proteins, such as Synaptotagmins, are implicated in facilitating the fusion process when cell membranes fuse together. There are six known human Ferlins: Dysferlin (Fer1L1), Otoferlin (Fer1L2), Myoferlin (Fer1L3), Fer1L4, Fer1L5, and Fer1L6. Defects in these genes can lead to a wide range of diseases including muscular dystrophy (dysferlin), deafness (otoferlin), and infertility (fer-1, fertilization factor-1). Structurally they have 6 tandem C2 domains, designated as (C2A-C2F) and a single C-terminal transmembrane domain, though there is a new study that disputes this and claims that there are actually 7 tandem C2 domains with another C2 domain inserted between C2D and C2E. In a subset of them (Dysferlin, Myoferlin, and Fer1) there is an additional conserved domain called DysF. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the fifth C2 repeat, C2E, and has a type-II topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKPKGKSGTNDTYTIIQLGKEKYSTS--VAEKTLEPVWKEeaSFELPGLLiqgsPEKYILFLIVMHRSLV 92
Cdd:cd04037   2 VRVYVVRARNLQPKDPNGKSDPYLKIKLGKKKINDRdnYIPNTLNPVFGK--MFELEATL----PGNSILKISVMDYDLL 75

                        90       100
                ....*....|....*....|..
gi 7662394   93 GLDKFLGQVAINLNDIFEDKQR 114
Cdd:cd04037  76 GSDDLIGETVIDLEDRFFSKHR 97

C2 domain second repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); MCTPs are involved in Ca2+ signaling at the membrane. MCTP is composed of a variable N-terminal sequence, three C2 domains, two transmembrane regions (TMRs), and a short C-terminal sequence. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKPKGKSGTNDTYTIIQLGKEKYSTSVAEKTLEPVWKEEasFELPGLLIQGSpekyILFLIVMHRSLVGL 94
Cdd:cd08376   2 VTIVLVEGKNLPPMDDNGLSDPYVKFRLGNEKYKSKVCSKTLNPQWLEQ--FDLHLFDDQSQ----ILEIEVWDKDTGKK 75

                        90
                ....*....|..
gi 7662394   95 DKFLGQVAINLN 106
Cdd:cd08376  76 DEFIGRCEIDLS 87

C2 domain first repeat contained in Rab3-interacting molecule (RIM) proteins; RIMs are believed to organize specialized sites of the plasma membrane called active zones. They also play a role in controlling neurotransmitter release, plasticity processes, as well as memory and learning. RIM contains an N-terminal zinc finger domain, a PDZ domain, and two C-terminal C2 domains (C2A, C2B). C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. Members here have a type-I topology and do not bind Ca2+.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394    6 QAQKWFPTHVQ---VTVLQAKDLKPKGKSGTNDTYTIIQL-----GKEKYSTSVAEKTLEPVWKEeaSFELPGLLIQGSP 77
Cdd:cd04031   6 QIQLWYDKVTSqliVTVLQARDLPPRDDGSLRNPYVKVYLlpdrsEKSKRRTKTVKKTLNPEWNQ--TFEYSNVRRETLK 83

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*.
gi 7662394   78 EKYiLFLIVMHRSLVGLDKFLGQVAINLNDIFEDKQrrkTEWFRLE 123
Cdd:cd04031  84 ERT-LEVTVWDYDRDGENDFLGEVVIDLADALLDDE---PHWYPLQ 125

C2 domain third repeat present in Tricalbin-like proteins; 5 to 6 copies of the C2 domain are present in Tricalbin, a yeast homolog of Synaptotagmin, which is involved in membrane trafficking and sorting. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the third C2 repeat, C2C, and has a type-II topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   22 AKDLKPKGKSGTNDTYTIIQL-GKEKYSTSVAEKTLEPVWKEeaSFELPgllIQgSPEKYIlFLIVMHRSLVGLDKFLGQ 100
Cdd:cd04045  10 ANDLKNLEGVGKIDPYVRVLVnGIVKGRTVTISNTLNPVWDE--VLYVP---VT-SPNQKI-TLEVMDYEKVGKDRSLGS 82

                        90       100       110
                ....*....|....*....|....*....|....*..
gi 7662394  101 VAINLNDIFEDKQRRKTEWFRLESKQGKRIKNRGEIK 137
Cdd:cd04045  83 VEINVSDLIKKNEDGKYVEYDDEEERLKRLLSLKGVK 119

C2 domain third repeat present in uncharacterized human KIAA1228-like proteins; KIAA proteins are uncharacterized human proteins. They were compiled by the Kazusa mammalian cDNA project which identified more than 2000 human genes. They are identified by 4 digit codes that precede the KIAA designation. Many KIAA genes are still functionally uncharacterized including KIAA1228. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the third C2 repeat, C2C, and has a type-II topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394    4 SEQAQKwfpthVQVTVLQAKDLKPKGKSGTNDTYTIIQL--GKEK---YSTSVAEKTLEPVWKEeaSFELPglliQGSPE 78
Cdd:cd04030  12 SSQRQK-----LIVTVHKCRNLPPCDSSDIPDPYVRLYLlpDKSKstrRKTSVKKDNLNPVFDE--TFEFP----VSLEE 80

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*....
gi 7662394   79 KYILFLIVM---HRSLVGLDK-FLGQVAINLNDIfeDKQRRKTEWFRLE 123
Cdd:cd04030  81 LKRRTLDVAvknSKSFLSREKkLLGQVLIDLSDL--DLSKGFTQWYDLT 127

C2 domain first repeat present in Tricalbin-like proteins; 5 to 6 copies of the C2 domain are present in Tricalbin, a yeast homolog of Synaptotagmin, which is involved in membrane trafficking and sorting. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-II topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKPKGK-SGTNDTYTIIQLGKEKYS--TSVAEKTLEPVWKEEasfelpglliqgspeKYILF-------- 83
Cdd:cd04044   4 LAVTIKSARGLKGSDIiGGTVDPYVTFSISNRRELarTKVKKDTSNPVWNET---------------KYILVnsltepln 68

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 7662394   84 LIVMHRSLVGLDKFLGQVAINLNDIFED-KQRRKTEWFRLESkqgkriKNRGEIKVNIQFM 143
Cdd:cd04044  69 LTVYDFNDKRKDKLIGTAEFDLSSLLQNpEQENLTKNLLRNG------KPVGELNYDLRFF 123

C2 domain in Protein Kinase C (PKC) epsilon; A single C2 domain is found in PKC epsilon. The PKC family of serine/threonine kinases regulates apoptosis, proliferation, migration, motility, chemo-resistance, and differentiation. There are 3 groups: group 1 (alpha, betaI, beta II, gamma) which require phospholipids and calcium, group 2 (delta, epsilon, theta, eta) which do not require calcium for activation, and group 3 (xi, iota/lambda) which are atypical and can be activated in the absence of diacylglycerol and calcium. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. Members here have a type-II topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKP----------KGKSGTNDTYTIIQ-----LGKekysTSVAEKTLEPVWKEEasFElpgllIQGSPEK 79
Cdd:cd04014   6 LKIKICEAVDLKPtdwstrhavpKKGSQLLDPYVSIDvddthIGK----TSTKPKTNSPVWNEE--FT-----TEVHNGR 74

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*....
gi 7662394   80 YILFLiVMHRSLVGLDKFLGQVAINLNDIFEDKQRRKTEWFRLESkQGK 128
Cdd:cd04014  75 NLELT-VFHDAAIGPDDFVANCTISFEDLIQRGSGSFDLWVDLEP-QGK 121

C2 domain found in the Human chromosome 21 open reading frame 25 (C21orf25) protein; The members in this cd are named after the Human C21orf25 which contains a single C2 domain. Several other members contain a C1 domain downstream of the C2 domain. No other information on this protein is currently known. The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   17 VTVLQAKDLKpkGKSGTNDTYTIIQLGK--EKYSTSVAEKTLEPVWKEEASFELPGLliqgspEKYILFLIVMHRSlVGL 94
Cdd:cd08678   3 VKNIKANGLS--EAAGSSNPYCVLEMDEppQKYQSSTQKNTSNPFWDEHFLFELSPN------SKELLFEVYDNGK-KSD 73

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*....
gi 7662394   95 DKFLGQVAINLnDIFEdKQRRKTEWFRLESKQGKRIKNRGEIKVNIQFM 143
Cdd:cd08678  74 SKFLGLAIVPF-DELR-KNPSGRQIFPLQGRPYEGDSVSGSITVEFLFM 120

C2 domain present in the Human neural precursor cell-expressed, developmentally down-regulated 4 (NEDD4) and NEDD4-like (NEDD4L/NEDD42); Nedd4 and Nedd4-2 are two of the nine members of the Human Nedd4 family. All vertebrates appear to have both Nedd4 and Nedd4-2 genes. They are thought to participate in the regulation of epithelial Na+ channel (ENaC) activity. They also have identical specificity for ubiquitin conjugating enzymes (E2). Nedd4 and Nedd4-2 are composed of a C2 domain, 2-4 WW domains, and a ubiquitin ligase Hect domain. Their WW domains can bind PPxY (PY) or LPSY motifs, and in vitro studies suggest that WW3 and WW4 of both proteins bind PY motifs in the key substrates, with WW3 generally exhibiting higher affinity. Most Nedd4 family members, especially Nedd4-2, also have multiple splice variants, which might play different roles in regulating their substrates. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   14 HVQVTVLQAKDLKPKGKSGTNDTYTIIQLGKEKYSTSVAE-------KTLEPVWKEEasfelpgLLIQGSPEKYILFLIV 86
Cdd:cd04033   1 ILRVKVLAGIDLAKKDIFGASDPYVKISLYDPDGNGEIDSvqtktikKTLNPKWNEE-------FFFRVNPREHRLLFEV 73

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 7662394   87 MHRSLVGLDKFLGQVAINLNDIFEDKQRRK----TEWFRLESKQGKRiKNRGEIKVNIQFM 143
Cdd:cd04033  74 FDENRLTRDDFLGQVEVPLNNLPTETPGNErrytFKDYLLRPRSSKS-RVKGHLRLYMAYL 133

C2 domain third repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); MCTPs are involved in Ca2+ signaling at the membrane. The cds in this family contain multiple C2 domains as well as a C-terminal PRT domain. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the third C2 repeat, C2C, and has a type-II topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   14 HVQVTVLQAKDLKPKGKSGTNDTYTIIQLGKEKYSTSVAEKTLEPVWKEEASFelpglliqgsPEKYI---LFLIVMHRS 90
Cdd:cd08377   2 FLQVKVIRASGLAAADIGGKSDPFCVLELVNARLQTHTIYKTLNPEWNKIFTF----------PIKDIhdvLEVTVYDED 71

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*.
gi 7662394   91 LVGLDKFLGQVAINLNDIfEDKQRRkteWFRLESKQGKRiKNRGEI 136
Cdd:cd08377  72 KDKKPEFLGKVAIPLLSI-KNGERK---WYALKDKKLRT-RAKGSI 112

C2 domain second repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); plant subset; MCTPs are involved in Ca2+ signaling at the membrane. Plant-MCTPs are composed of a variable N-terminal sequence, four C2 domains, two transmembrane regions (TMRs), and a short C-terminal sequence. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   17 VTVLQAKDLKPKGksgtNDTYTIIQLGKEKYSTSVAEKTLEPVWKEeaSFELPGLLIQGSpekyilFL-IVMHRSLVGLD 95
Cdd:cd08378   4 VRVVKARGLPANS----NDPVVEVKLGNYKGSTKAIERTSNPEWNQ--VFAFSKDRLQGS------TLeVSVWDKDKAKD 71

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....
gi 7662394   96 KFLGQVAINLNDIfedkQRRK-------TEWFRLESKQGKRIknRGEIKVNIQF 142
Cdd:cd08378  72 DFLGGVCFDLSEV----PTRVppdsplaPQWYRLEDKKGGRV--GGELMLAVWF 119

C2 domain third repeat found in Multiple C2 domain and Transmembrane region Proteins (MCTP); plant subset; MCTPs are involved in Ca2+ signaling at the membrane. Plant-MCTPs are composed of a variable N-terminal sequence, four C2 domains, two transmembrane regions (TMRs), and a short C-terminal sequence. It is one of four protein classes that are anchored to membranes via a transmembrane region; the others being synaptotagmins, extended synaptotagmins, and ferlins. MCTPs are the only membrane-bound C2 domain proteins that contain two functional TMRs. MCTPs are unique in that they bind Ca2+ but not phospholipids. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the third C2 repeat, C2C, and has a type-II topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKPKGKSGTNDTYTIIQLGKEKYSTSVAE-KTLEPVWKEEASFelpgllIQGSPEKYILFLIVMHRSLVG 93
Cdd:cd04019   2 LRVTVIEAQDLVPSDKNRVPEVFVKAQLGNQVLRTRPSQtRNGNPSWNEELMF------VAAEPFEDHLILSVEDRVGPN 75

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....
gi 7662394   94 LDKFLGQVAINLNDIFEDKQRRKTE--WFRLE-----SKQGKRIKNRGEIKVNI 140
Cdd:cd04019  76 KDEPLGRAVIPLNDIERRVDDRPVPsrWFSLErpggaMEQKKKRKFASRIHLRL 129

C2 domain present in Phosphatidylserine decarboxylase (PSD); PSD is involved in the biosynthesis of aminophospholipid by converting phosphatidylserine (PtdSer) to phosphatidylethanolamine (PtdEtn). There is a single C2 domain present and it is thought to confer PtdSer binding motif that is common to PKC and synaptotagmin. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   15 VQVTVLQAKDLKP-KGKSGTN---DTYTIIQLGKEKYSTSVAEKTLEPVWKEEASFELpglliqGSPEK-YILFLIVMHR 89
Cdd:cd04039   3 VFMEIKSITDLPPlKNMTRTGfdmDPFVIISFGRRVFRTSWRRHTLNPVFNERLAFEV------YPHEKnFDIQFKVLDK 76

                        90       100       110
                ....*....|....*....|....*....|
gi 7662394   90 SLVGLDKFLGQVAINLNDIFEDKQRRKTEW 119
Cdd:cd04039  77 DKFSFNDYVATGSLSVQELLNAAPQPDPET 106

C2A domain first repeat present in Synaptotagmin 8; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   17 VTVLQAKDLKPKGKSGTNDTYTIIQL---GKEKYSTSVAEKTLEPVWKEEASFELPgllIQGSPEKYILFLIVMHRSLvG 93
Cdd:cd08387  20 VKLIQARNLQPRDFSGTADPYCKVRLlpdRSNTKQSKIHKKTLNPEFDESFVFEVP---PQELPKRTLEVLLYDFDQF-S 95

                        90       100       110
                ....*....|....*....|....*....|.
gi 7662394   94 LDKFLGQVAINLNDIfeDKQRRKTEWFRLES 124
Cdd:cd08387  96 RDECIGVVELPLAEV--DLSEKLDLWRKIQS 124

C2A domain first repeat present in Synaptotagmin 7; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 7, a member of class 2 synaptotagmins, is located in presynaptic plasma membranes in neurons, dense-core vesicles in endocrine cells, and lysosomes in fibroblasts. It has been shown to play a role in regulation of Ca2+-dependent lysosomal exocytosis in fibroblasts and may also function as a vesicular Ca2+-sensor. It is distinguished from the other synaptotagmins by having over 12 splice forms. Previously all synaptotagmins were thought to be calcium sensors in the regulation of neurotransmitter release and hormone secretion, but it has been shown that not all of them bind calcium. Of the 17 identified synaptotagmins only 8 bind calcium (1-3, 5-7, 9, 10). The function of the two C2 domains that bind calcium are: regulating the fusion step of synaptic vesicle exocytosis (C2A) and binding to phosphatidyl-inositol-3,4,5-triphosphate (PIP3) in the absence of calcium ions and to phosphatidylinositol bisphosphate (PIP2) in their presence (C2B). C2B also regulates also the recycling step of synaptic vesicles. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the first C2 repeat, C2A, and has a type-I topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   17 VTVLQAKDLKPKGKSGTNDTYTIIQL---GKEKYSTSVAEKTLEPVWKEEASFElpGLLIQGSPEKyILFLIVMHRSLVG 93
Cdd:cd08386  20 LKILKAVELPAKDFSGTSDPFVKIYLlpdKKHKLETKVKRKNLNPHWNETFLFE--GFPYEKLQQR-VLYLQVLDYDRFS 96

                        90
                ....*....|....*
gi 7662394   94 LDKFLGQVAINLNDI 108
Cdd:cd08386  97 RNDPIGEVSLPLNKV 111

C2 domain second repeat present in Rabphilin and Double C2 domain; Rabphilin is found neurons and in neuroendrocrine cells, while Doc2 is found not only in the brain but in tissues, including mast cells, chromaffin cells, and osteoblasts. Rabphilin and Doc2s share highly homologous tandem C2 domains, although their N-terminal structures are completely different: rabphilin contains an N-terminal Rab-binding domain (RBD),7 whereas Doc2 contains an N-terminal Munc13-1-interacting domain (MID). C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-I topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662394   17 VTVLQAKDLKPKGKSGTNDTYTIIQL-----GKEKYSTSVAEKTLEPVWKEEASFELPglliQGSPEKYILFLIVMHRSL 91
Cdd:cd08384  17 VGIIRCVNLAAMDANGYSDPFVKLYLkpdagKKSKHKTQVKKKTLNPEFNEEFFYDIK----HSDLAKKTLEITVWDKDI 92

                        90       100       110       120
                ....*....|....*....|....*....|....*....|.
gi 7662394   92 VGLDKFLGQVAINLN----------DIFEDKQRRKTEWFRL 122
Cdd:cd08384  93 GKSNDYIGGLQLGINakgerlrhwlDCLKNPDKKIEAWHTL 133

C2 domain in Munc13 (mammalian uncoordinated) proteins; fungal group; C2-like domains are thought to be involved in phospholipid binding in a Ca2+ independent manner in both Unc13 and Munc13. Caenorabditis elegans Unc13 has a central domain with sequence similarity to PKC, which includes C1 and C2-related domains. Unc13 binds phorbol esters and DAG with high affinity in a phospholipid manner. Mutations in Unc13 results in abnormal neuronal connections and impairment in cholinergic neurotransmission in the nematode. Munc13 is the mammalian homolog which are expressed in the brain. There are 3 isoforms (Munc13-1, -2, -3) and are thought to play a role in neurotransmitter release and are hypothesized to be high-affinity receptors for phorbol esters. Unc13 and Munc13 contain both C1 and C2 domains. There are two C2 related domains present, one central and one at the carboxyl end. Munc13-1 contains a third C2-like domain. Munc13 interacts with syntaxin, synaptobrevin, and synaptotagmin suggesting a role for these as scaffolding proteins. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions. This cd contains the second C2 repeat, C2B, and has a type-II topology.

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gi 7662394   17 VTVLQAKDLKPKGKSGTNDTY---TIIQLGKEKYSTSVAEKTLEPVWKEEasFELPgllIQGSPEKYILFlIVMHRSLVG 93
Cdd:cd04043   5 IRIVRAENLKADSSNGLSDPYvtlVDTNGKRRIAKTRTIYDTLNPRWDEE--FELE---VPAGEPLWISA-TVWDRSFVG 78

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gi 7662394   94 LDKFLG 99
Cdd:cd04043  79 KHDLCG 84