Synaptotagmin 1 is a synaptic vesicle membrane glycoprotein that is widely expressed throughout the CNS and is generally thought to act as the Ca2+ sensor in the regulation of exocytosis and neurotransmitter release. Studies indicate that synaptotagmin's Ca2+ mediated binding of SNAP25 is essential for the Ca2+ dependent triggering of membrane. Synaptotagmin 1 may have a regulatory role in the membrane interactions during trafficking of synaptic vesicles at the active zone of the synapse. Further, Synaptotagmin 1 binds acidic phospholipids with a specificity that requires the presence of both an acidic head group and a diacyl backbone. A Ca(2+)-dependent interaction between synaptotagmin and putative receptors for activated protein kinase C has been reported.