May have a regulatory role in the membrane interactions during trafficking of synaptic vesicles at the active zone of the synapse. It binds acidic phospholipids with a specificity that requires the presence of both an acidic head group and a diacyl backbone. Binds 3 Ca(2+) ions per subunit. The ions are bound to the C2 domains. Homodimer or homotrimer (Potential). Identified in a complex with Syn and nwk (PubMed:29568072). Interacts with StnA and StnB via its second C2 domain. This interaction may mediate its retrieval from the plasma membrane, thereby facilitating the internalization of multiple synaptic vesicles from the plasma membrane. Synaptic vesicles in neurons. Partially edited. Belongs to the synaptotagmin family. Intron retention. Contaminating sequence. Potential poly-A sequence.