Synaptotagmin V (SYT5)

The synaptotagmins are a family of type III membrane proteins characterized by cytoplasmic repeats related to the protein kinase C regulatory (C2) domains which are thought to bind calcium. The synaptotagmins may act both as negative regulators of vesicle fusion, allowing fusion in the presence of calcium, and as calcium receptors or sensor molecules.Hudson and Birnbaum (1995) cloned a synaptotagmin cDNA from a rat adipose tissue cDNA library. The sequence predicts a 386-amino acid protein with 49% identity to synaptotagmins 1 and 2 . The 1.7-kb synaptotagmin-5 mRNA is expressed in rat kidney, adipose tissue, lung and heart, and at higher levels in brain. An antibody to the SYT5 gene product detected an approximately 50-kD protein.