C2A domain first repeat present in Synaptotagmins 14 and 16; Synaptotagmin 14 and 16 are membrane-trafficking proteins in specific tissues outside the brain. Both of these contain C-terminal tandem C2 repeats, but only Synaptotagmin 14 has an N-terminal transmembrane domain and a putative fatty-acylation site. 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 and this is indeed the case here. 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 2217266222 222 KYGTLDVTFDYDSQEQKLLVTVTAVTDIPTYNRTGGNSWQVHLVLLPIKKQRAKTSIQRGPCPVFTETFKFNHVESEMIG 301
Cdd:cd08389     1 KCGDLDVAFEYDPSARKLTVTVIRAQDIPTKDRGGASSWQVHLVLLPSKKQRAKTKVQRGPNPVFNETFTFSRVEPEELN 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 2217266222 302 NYAVRFRLYGVHRMKKEKIVGEKIFYLTKLNLQGKMSLPVILEP 345
Cdd:cd08389    81 NMALRFRLYGVERMRKERLIGEKVVPLSQLNLEGETTVWLTLEP 124

C2A domain first repeat present in Synaptotagmins 14 and 16; Synaptotagmin 14 and 16 are membrane-trafficking proteins in specific tissues outside the brain. Both of these contain C-terminal tandem C2 repeats, but only Synaptotagmin 14 has an N-terminal transmembrane domain and a putative fatty-acylation site. 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 and this is indeed the case here. 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 2217266222 222 KYGTLDVTFDYDSQEQKLLVTVTAVTDIPTYNRTGGNSWQVHLVLLPIKKQRAKTSIQRGPCPVFTETFKFNHVESEMIG 301
Cdd:cd08389     1 KCGDLDVAFEYDPSARKLTVTVIRAQDIPTKDRGGASSWQVHLVLLPSKKQRAKTKVQRGPNPVFNETFTFSRVEPEELN 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 2217266222 302 NYAVRFRLYGVHRMKKEKIVGEKIFYLTKLNLQGKMSLPVILEP 345
Cdd:cd08389    81 NMALRFRLYGVERMRKERLIGEKVVPLSQLNLEGETTVWLTLEP 124

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 2217266222  421 KHLIGGQVYIIRDTYVKLTLLnsmGQEMSKCKTSIRRGQPNPVYKETFVFQVALFQLSDvtLILSVYNKRSMKRKEMIGW 500
Cdd:smart00239  10 RNLPPKDKGGKSDPYVKVSLD---GDPKEKKKTKVVKNTLNPVWNETFEFEVPPPELAE--LEIEVYDKDRFGRDDFIGQ 84

                   ....*..
gi 2217266222  501 ISLGLNS 507
Cdd:smart00239  85 VTIPLSD 91

C2 domain;

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217266222 265 VLLPIKKQRAKTSIQR-GPCPVFTETFKFnHVESEMigNYAVRFRLYGVHRMKKEKIVGE 323
Cdd:pfam00168  28 VYLLDGKQKKKTKVVKnTLNPVWNETFTF-SVPDPE--NAVLEIEVYDYDRFGRDDFIGE 84

C2A domain first repeat present in Synaptotagmins 14 and 16; Synaptotagmin 14 and 16 are membrane-trafficking proteins in specific tissues outside the brain. Both of these contain C-terminal tandem C2 repeats, but only Synaptotagmin 14 has an N-terminal transmembrane domain and a putative fatty-acylation site. 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 and this is indeed the case here. 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 2217266222 222 KYGTLDVTFDYDSQEQKLLVTVTAVTDIPTYNRTGGNSWQVHLVLLPIKKQRAKTSIQRGPCPVFTETFKFNHVESEMIG 301
Cdd:cd08389     1 KCGDLDVAFEYDPSARKLTVTVIRAQDIPTKDRGGASSWQVHLVLLPSKKQRAKTKVQRGPNPVFNETFTFSRVEPEELN 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 2217266222 302 NYAVRFRLYGVHRMKKEKIVGEKIFYLTKLNLQGKMSLPVILEP 345
Cdd:cd08389    81 NMALRFRLYGVERMRKERLIGEKVVPLSQLNLEGETTVWLTLEP 124

C2 domain second 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 second C2 repeat, C2B, and has a type-I topology.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217266222 380 EILIGLLYNATTGRLSAEVIKGshfKNLAANRppnglfcclkhlIGGQvyiiRDTYVKLTLLNSmGQEMSKCKTSIRRGQ 459
Cdd:cd08405     3 ELLLSLCYNPTANRITVNIIKA---RNLKAMD------------INGT----SDPYVKVWLMYK-DKRVEKKKTVIKKRT 62

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217266222 460 PNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLNSSGeEELNHWTEMKESKGQQVCRWHAL 533
Cdd:cd08405    63 LNPVFNESFIFNIPLERLRETTLIITVMDKDRLSRNDLIGKIYLGWKSGG-LELKHWKDMLSKPRQPVAQWHRL 135

C2 domain second repeat present in Synaptotagmin 1; 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 the 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. It, like synaptotagmin-2, has an N-glycosylated N-terminus. Synaptotagmin 4, a member of class 4 synaptotagmins, is located in the brain. It functions are unknown. It, like synaptotagmin-11, has an Asp to Ser substitution in its C2A domain. 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 2217266222 380 EILIGLLYNATTGRLSAEVIKGshfKNLAanrppnglfcclKHLIGGqvyiIRDTYVKLTLLNSmGQEMSKCKTSIRRGQ 459
Cdd:cd08402     3 DICFSLRYVPTAGKLTVVILEA---KNLK------------KMDVGG----LSDPYVKIHLMQN-GKRLKKKKTTIKKRT 62

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217266222 460 PNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLNSSGeEELNHWTEMKESKGQQVCRWHAL 533
Cdd:cd08402    63 LNPYYNESFSFEVPFEQIQKVHLIVTVLDYDRIGKNDPIGKVVLGCNATG-AELRHWSDMLASPRRPIAQWHTL 135

C2 domain second repeat present in Synaptotagmin 17; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 17 is located in the brain, kidney, and prostate and is thought to be a peripheral membrane protein. 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 2217266222 380 EILIGLLYNATTGRLSAEVIKGshfknlaanrppnglfcclKHLIGGQVYIIRDTYVKLTLLNsmGQEMSKCK-TSIRRG 458
Cdd:cd08410     2 ELLLSLNYLPSAGRLNVDIIRA-------------------KQLLQTDMSQGSDPFVKIQLVH--GLKLIKTKkTSCMRG 60

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217266222 459 QPNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLNSSGEEELNHWTEMKESKGQQVCRWHAL 533
Cdd:cd08410    61 TIDPFYNESFSFKVPQEELENVSLVFTVYGHNVKSSNDFIGRIVIGQYSSGPSETNHWRRMLNSQRTAVEQWHSL 135

C2 domain second repeat present in Synaptotagmin 15; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. It is thought to be involved in the trafficking and exocytosis of secretory vesicles in non-neuronal tissues and is Ca2+ independent. Human synaptotagmin 15 has 2 alternatively spliced forms that encode proteins with different C-termini. The larger, SYT15a, contains a N-terminal TM region, a putative fatty-acylation site, and 2 tandem C terminal C2 domains. The smaller, SYT15b, lacks the C-terminal portion of the second C2 domain. Unlike most other synaptotagmins it is nearly absent in the brain and rather is found in the heart, lungs, skeletal muscle, and testis. 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 2217266222 380 EILIGLLYNATTGRLSAEVIKGSHFKNLAANrppnglfcclkhliggqvyiIRDTYVKLTLLNSMGQEMSKcKTSIRRGQ 459
Cdd:cd08409     3 DIQISLTYNPTLNRLTVVVLRARGLRQLDHA--------------------HTSVYVKVSLMIHNKVVKTK-KTEVVDGA 61

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217266222 460 PNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLG--LNSSGeEELNHWTEMKESKGQQVCRWHAL 533
Cdd:cd08409    62 ASPSFNESFSFKVTSRQLDTASLSLSVMQSGGVRKSKLLGRVVLGpfMYARG-KELEHWNDMLSKPKELIKRWHAL 136

C2 domain second repeat present in Synaptotagmin 12; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 12, a member of class 6 synaptotagmins, is located in the brain. It functions are unknown. It, like synaptotagmins 8 and 13, do not have any consensus Ca2+ binding sites. 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 2217266222 380 EILIGLLYNATTGRLSAEVIKGshfKNLAANRPPNglfcclkhliggqvyiIRDTYVKLTLLNSmGQEMSKCKTSIRRGQ 459
Cdd:cd08406     3 EILLSLSYLPTAERLTVVVVKA---RNLVWDNGKT----------------TADPFVKVYLLQD-GRKISKKKTSVKRDD 62

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217266222 460 PNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLNSSGeEELNHWTEMKESKGQQVCRWHAL 533
Cdd:cd08406    63 TNPIFNEAMIFSVPAIVLQDLSLRVTVAESTEDGKTPNVGHVIIGPAASG-MGLSHWNQMLASLRKPVAMWHPL 135

C2 domain second repeat present in Synaptotagmin 13; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. Synaptotagmin 13, a member of class 6 synaptotagmins, is located in the brain. It functions are unknown. It, like synaptotagmins 8 and 12, does not have any consensus Ca2+ binding sites. 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 2217266222 380 EILIGLLYNATTGRLSAEVIKGshfKNLAANRppnglfccLKHLIGgqvyiiRDTYVKLTLlNSMGQEMSKCKTSIRRGQ 459
Cdd:cd08407     3 EVLLSISYLPAANRLLVVVIKA---KNLHSDQ--------LKLLLG------IDVSVKVTL-KHQNAKLKKKQTKRAKHK 64

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217266222 460 PNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLNSSGEEeLNHWTEMKESKGQQVCRWHAL 533
Cdd:cd08407    65 INPVWNEMIMFELPSELLAASSVELEVLNQDSPGQSLPLGRCSLGLHTSGTE-RQHWEEMLDNPRRQIAMWHQL 137

C2 domain first repeat present in Synaptotagmin-like proteins; All Slp members basically share an N-terminal Slp homology domain (SHD) and C-terminal tandem C2 domains (named the C2A domain and the C2B domain) with the SHD and C2 domains being separated by a linker sequence of various length. Slp1/JFC1 and Slp2/exophilin 4 promote granule docking to the plasma membrane. Additionally, their C2A domains are both Ca2+ independent, unlike the case in Slp3 and Slp4/granuphilin in which their C2A domains are Ca2+ dependent. It is thought that SHD (except for the Slp4-SHD) functions as a specific Rab27A/B-binding domain. In addition to Slps, rabphilin, Noc2, and Munc13-4 also function as Rab27-binding proteins. It has been demonstrated that Slp3 and Slp4/granuphilin promote dense-core vesicle exocytosis. Slp5 mRNA has been shown to be restricted to human placenta and liver suggesting a role in Rab27A-dependent membrane trafficking in specific tissues. 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 2217266222 380 EILIGLLYNATTGRLSAEVIKGshfKNLAANRPpnglfccLKHLiggqvyiiRDTYVKLTLLNSMgQEMSKCKTSIRRGQ 459
Cdd:cd08521     2 EIEFSLSYNYKTGSLEVHIKEC---RNLAYADE-------KKKR--------SNPYVKVYLLPDK-SKQSKRKTSVKKNT 62

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 2217266222 460 PNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLNS 507
Cdd:cd08521    63 TNPVFNETLKYHISKSQLETRTLQLSVWHHDRFGRNTFLGEVEIPLDS 110

C2A domain first repeat present in Synaptotagmins 15 and 17; Synaptotagmin is a membrane-trafficking protein characterized by a N-terminal transmembrane region, a linker, and 2 C-terminal C2 domains. It is thought to be involved in the trafficking and exocytosis of secretory vesicles in non-neuronal tissues and is Ca2+ independent. Human synaptotagmin 15 has 2 alternatively spliced forms that encode proteins with different C-termini. The larger, SYT15a, contains a N-terminal TM region, a putative fatty-acylation site, and 2 tandem C terminal C2 domains. The smaller, SYT15b, lacks the C-terminal portion of the second C2 domain. Unlike most other synaptotagmins it is nearly absent in the brain and rather is found in the heart, lungs, skeletal muscle, and testis. Synaptotagmin 17 is located in the brain, kidney, and prostate and is thought to be a peripheral membrane protein. 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 2217266222 387 YNATTGRLSAEVIKgshfknlAANRPPNGLFCclKHliggqvyiiRDTYVKLTLLNSmgQEMSKcKTSIRRGQPNPVYKE 466
Cdd:cd08390     9 YDLEEEQLTVSLIK-------ARNLPPRTKDV--AH---------CDPFVKVCLLPD--ERRSL-QSKVKRKTQNPNFDE 67

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 2217266222 467 TFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLN 506
Cdd:cd08390    68 TFVFQVSFKELQRRTLRLSVYDVDRFSRHCIIGHVLFPLK 107

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 2217266222 433 DTYVKLTLLNSMGQemsKCKTSIRRGQPNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLNSsgeEE 512
Cdd:cd08385    38 DPYVKVYLLPDKKK---KFETKVHRKTLNPVFNETFTFKVPYSELGNKTLVFSVYDFDRFSKHDLIGEVRVPLLT---VD 111

                  ....*.
gi 2217266222 513 LNHWTE 518
Cdd:cd08385   112 LGHVTE 117

C2 domain second repeat present in Synaptotagmin-like proteins 1-4; All Slp members basically share an N-terminal Slp homology domain (SHD) and C-terminal tandem C2 domains (named the C2A domain and the C2B domain) with the SHD and C2 domains being separated by a linker sequence of various length. Slp1/JFC1 and Slp2/exophilin 4 promote granule docking to the plasma membrane. Additionally, their C2A domains are both Ca2+ independent, unlike the case in Slp3 and Slp4/granuphilin in which their C2A domains are Ca2+ dependent. It is thought that SHD (except for the Slp4-SHD) functions as a specific Rab27A/B-binding domain. In addition to Slps, rabphilin, Noc2, and Munc13-4 also function as Rab27-binding proteins. It has been demonstrated that Slp3 and Slp4/granuphilin promote dense-core vesicle exocytosis. 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 2217266222 433 DTYVKLTLLnSMGQEMSKCKTSIRRGQPNPVYKETFVF-QVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLNS---- 507
Cdd:cd04020    49 DSFVKCYLL-PDKSKKSKQKTPVVKKSVNPVWNHTFVYdGVSPEDLSQACLELTVWDHDKLSSNDFLGGVRLGLGTgksy 127

                          90       100
                  ....*....|....*....|....*
gi 2217266222 508 --------SGEEELNHWTEMKESKG 524
Cdd:cd04020   128 gqavdwmdSTGEEILLWQKMLDNPN 152

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217266222 223 YGTLDVTFDYDSQEQKLLVTVTAVTDIPTYNRTGGNSWQVHLVLLPIKKQ--RAKTSIQRGPC-PVFTETFKF 292
Cdd:cd04030     2 LGRIQLTIRYSSQRQKLIVTVHKCRNLPPCDSSDIPDPYVRLYLLPDKSKstRRKTSVKKDNLnPVFDETFEF 74

C2 domain first repeat present in Synaptotagmin-like proteins 4 and 5; All Slp members basically share an N-terminal Slp homology domain (SHD) and C-terminal tandem C2 domains (named the C2A domain and the C2B domain) with the SHD and C2 domains being separated by a linker sequence of various length. SHD of Slp (except for the Slp4-SHD) function as a specific Rab27A/B-binding domain. In addition to Slp, rabphilin, Noc2, and Munc13-4 also function as Rab27-binding proteins. It has been demonstrated that Slp4/granuphilin promotes dense-core vesicle exocytosis. The C2A domain of Slp4 is Ca2+ dependent. Slp5 mRNA has been shown to be restricted to human placenta and liver suggesting a role in Rab27A-dependent membrane trafficking in specific tissues. 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 2217266222 380 EILIGLLYNATTGRLSAeVIKGSHfkNLAANRPpnglfccLKHLiggqvyiiRDTYVKLTLLNSMGQEmSKCKTSIRRGQ 459
Cdd:cd04029     3 EILFSLSYDYKTQSLNV-HVKECR--NLAYGDE-------AKKR--------SNPYVKTYLLPDKSRQ-SKRKTSIKRNT 63

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 2217266222 460 PNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGLNS 507
Cdd:cd04029    64 TNPVYNETLKYSISHSQLETRTLQLSVWHYDRFGRNTFLGEVEIPLDS 111

C2 domain first repeat found in Tac2-N (Tandem C2 protein in Nucleus); Tac2-N contains two C2 domains and a short C-terminus including a WHXL motif, which are key in stabilizing transport vesicles to the plasma membrane by binding to a plasma membrane. However unlike the usual carboxyl-terminal-type (C-type) tandem C2 proteins, it lacks a transmembrane domain, a Slp-homology domain, and a Munc13-1-interacting domain. Homology search analysis indicate that no known protein motifs are located in its N-terminus, making Tac2-N a novel class of Ca2+-independent, C-type tandem C2 proteins. 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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217266222 452 KTSIRRGQPNPVYKETFVFQVALFQLSDVTLILSVynKRSMKRKEMIGWISLGLNSSGEEELNHWTEM 519
Cdd:cd08684    38 KSSAKEGSNDIEFMETFVFAIKLQNLQTVRLVFKI--QTQTPRKRTIGECSLSLRTLSTQETDHWLEI 103

C2 domain second repeat found in Tac2-N (Tandem C2 protein in Nucleus); Tac2-N contains two C2 domains and a short C-terminus including a WHXL motif, which are key in stabilizing transport vesicles to the plasma membrane by binding to a plasma membrane. However unlike the usual carboxyl-terminal-type (C-type) tandem C2 proteins, it lacks a transmembrane domain, a Slp-homology domain, and a Munc13-1-interacting domain. Homology search analysis indicate that no known protein motifs are located in its N-terminus, making Tac2-N a novel class of Ca2+-independent, C-type tandem C2 proteins. 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 2217266222 435 YVKLTLLnSMGQEMSKCKTSIRRGQPNPV-YKETFVFQVALfQLSDVTLILSVYNKRSMKRKEMIGWISLGLNSSGEEEL 513
Cdd:cd08692    38 FVKVGMF-STGGLLYKKKTRLVKSSNGQVkWGETMIFPVTQ-QEHGIQFLIKLYSRSSVRRKHFLGQVWISSDSSSSEAV 115

                          90       100
                  ....*....|....*....|
gi 2217266222 514 NHWTEMKESKGQQVCRWHAL 533
Cdd:cd08692   116 EQWKDTIANPEKVVTKWHSL 135

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 2217266222 232 YDSQEQKLLVTVTAVTDIPTYNRTGGNSWQVHLVLLP----IKKQraKTSIQRG-PCPVFTETFKFNhVESEMIGNYAVR 306
Cdd:cd00276     9 YLPTAERLTVVVLKARNLPPSDGKGLSDPYVKVSLLQggkkLKKK--KTSVKKGtLNPVFNEAFSFD-VPAEQLEEVSLV 85

                          90
                  ....*....|....*.
gi 2217266222 307 FRLYGVHRMKKEKIVG 322
Cdd:cd00276    86 ITVVDKDSVGRNEVIG 101

C2 domain present in Phosphoinositide-specific phospholipases C (PLC); PLCs are involved in the hydrolysis of phosphatidylinositol-4,5-bisphosphate (PIP2) to d-myo-inositol-1,4,5-trisphosphate (1,4,5-IP3) and sn-1,2-diacylglycerol (DAG). 1,4,5-IP3 and DAG are second messengers in eukaryotic signal transduction cascades. PLC is composed of a N-terminal PH domain followed by a series of EF hands, a catalytic TIM barrel and a C-terminal C2 domain. 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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217266222 431 IRDTYVKLTLLNSMGQEMSKCKTS-IRRGQPNPVYKETFVFQVALFQLSdvTLILSVYNKrSMKRKEMIGWISLGLNS 507
Cdd:cd00275    24 IVDPYVEVEIHGLPADDSAKFKTKvVKNNGFNPVWNETFEFDVTVPELA--FLRFVVYDE-DSGDDDFLGQACLPLDS 98

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 2217266222  238 KLLVTVTAVTDIPTYNRTGGNSWQVHLVLLPIKKQRAKTSIQRG-PCPVFTETFKFNHVESEmigNYAVRFRLYGVHRMK 316
Cdd:smart00239   1 TLTVKIISARNLPPKDKGGKSDPYVKVSLDGDPKEKKKTKVVKNtLNPVWNETFEFEVPPPE---LAELEIEVYDKDRFG 77

                           90       100
                   ....*....|....*....|.
gi 2217266222  317 KEKIVGEKIFYLTKLNLQGKM 337
Cdd:smart00239  78 RDDFIGQVTIPLSDLLLGGRH 98

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 2217266222 433 DTYVKLTLLNSMGQEMskcKTSIRRGQPNPVYKETFVFQVALFQ-LSDVTLILSVYNKRSMKRKEMIGWISLGLNSSG-E 510
Cdd:cd08386    38 DPFVKIYLLPDKKHKL---ETKVKRKNLNPHWNETFLFEGFPYEkLQQRVLYLQVLDYDRFSRNDPIGEVSLPLNKVDlT 114

                          90
                  ....*....|
gi 2217266222 511 EELNHWTEMK 520
Cdd:cd08386   115 EEQTFWKDLK 124

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 2217266222 223 YGTLDVTFDYDSQEQKLLVTVTAVTDIPTYNRTGGNSWQVHLVLLPIK----KQRAKTsIQRGPCPVFTETFKFNHVESE 298
Cdd:cd04031     2 TGRIQIQLWYDKVTSQLIVTVLQARDLPPRDDGSLRNPYVKVYLLPDRseksKRRTKT-VKKTLNPEWNQTFEYSNVRRE 80

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 2217266222 299 MIGNYAVRFRLYGVHRMKKEKIVGEKIFYLTKLNLQGKM 337
Cdd:cd04031    81 TLKERTLEVTVWDYDRDGENDFLGEVVIDLADALLDDEP 119

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 2217266222 433 DTYVKLTLLNSMGQEMskcKTSIRRGQPNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGL-NSSGEE 511
Cdd:cd08387    38 DPYCKVRLLPDRSNTK---QSKIHKKTLNPEFDESFVFEVPPQELPKRTLEVLLYDFDQFSRDECIGVVELPLaEVDLSE 114

                  ....*....
gi 2217266222 512 ELNHWTEMK 520
Cdd:cd08387   115 KLDLWRKIQ 123

C2 domain (first repeat) of Ras GTPase activating proteins (GAPs); RasGAPs suppress Ras function by enhancing the GTPase activity of Ras proteins resulting in the inactive GDP-bound form of Ras. In this way it can control cellular proliferation and differentiation. The proteins here all contain either a single C2 domain or two tandem C2 domains, a Ras-GAP domain, and a pleckstrin homology (PH)-like domain. 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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217266222 451 CKTSIRRGqPNPVYKETFVFQVALFQLSDVTLILSVYNKRSMKRKEMIGWISLGlnssgeeelnhwtemKESKGQQVCRW 530
Cdd:cd08383    32 ARTKTVEK-LNPFWGEEFVFDDPPPDVTFFTLSFYNKDKRSKDRDIVIGKVALS---------------KLDLGQGKDEW 95

                  ...
gi 2217266222 531 HAL 533
Cdd:cd08383    96 FPL 98

C2 domain second repeat in Munc13 (mammalian uncoordinated)-like proteins; 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 third C2 repeat, C2C, and has a type-II topology.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217266222 433 DTYVKLTLLNSMG-QEMSKCKTSIRRGQPNPVYKETFVFQVALFQLS--DVTLILSVYNKRSMKRKEMIGWISLGLNS 507
Cdd:cd04009    38 DPFVKVELLPRHLfPDVPTPKTQVKKKTLFPLFDESFEFNVPPEQCSveGALLLFTVKDYDLLGSNDFEGEAFLPLND 115