Synaptotagmin: Difference between revisions
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== Function == | == Function == | ||
'''Synaptotagmin''' (SYT) are calcium-binding proteins which are conserved from nematodes to humans. Fifteen SYTs have been identified in mammals<ref>PMID:18468511</ref>. | '''Synaptotagmin''' (SYT) are calcium-binding proteins which are conserved from nematodes to humans. Fifteen SYTs have been identified in mammals<ref>PMID:18468511</ref>. '''Synaptotagmin-1''' (SYT1) is a synaptic vesicle membrane protein and is a sensor which induces release in neurons upon binding of Ca+2 ions<ref>PMID:19412166</ref>. The C2A domain of SYT binds phospholipids in Ca+2-dependent manner<ref>PMID:9730811</ref>. The C2B domain of SYT promotes binding to other C2B domains and to accessory proteins. Ca+2 binding causes intramolecular association of domains C2A and C2B. The synaptic fusion apparatus includes the affinity between SYT and [[Syntaxin]]-1, This affinity increases by ca. 2 orders of magnitude upon binding of Ca+2<ref>PMID:7559535</ref>. | ||
'''Synaptotagmin-like proteins''' (SYTL) are required in a generation of a single apical surface per cell<ref>PMID:22820376</ref>. | '''Synaptotagmin-like proteins''' (SYTL) are required in a generation of a single apical surface per cell<ref>PMID:22820376</ref>. | ||
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== Structural highlights == | == Structural highlights == | ||
SYT-2 structure contains the SMP (synaptotagmin-like-mitochondrial-lipid binding) domain, followed by the <scene name='80/802718/Cv/ | SYT-2 structure contains the SMP (synaptotagmin-like-mitochondrial-lipid binding) domain, followed by the <scene name='80/802718/Cv/12'>C2A Ca+2-binding, C2B</scene>, spacer and C2C domains. At the cup-shaped cavity at the of SYT C2A domain there are three tightly clustered Ca+2 binding sites formed by canonical 5 aspartates<ref>PMID:24373768</ref>. | ||
*<scene name='80/802718/Cv/8'>1st Ca+2 binding site</scene>. Water molecules are shown as red spheres. | *<scene name='80/802718/Cv/8'>1st Ca+2 binding site</scene>. Water molecules are shown as red spheres. | ||
*<scene name='80/802718/Cv/9'>2nd Ca+2 binding site</scene>. | *<scene name='80/802718/Cv/9'>2nd Ca+2 binding site</scene>. |