Synaptotagmin-15 (Syt15) belongs to the synaptotagmin family, which is a group of membrane-trafficking proteins that contain two C-terminal C2 domains (known as C2A and C2B domains). Most of the synaptotagmins have a unique N-terminal domain that is involved in membrane anchoring or specific ligand binding. Mammals contain 16 synaptotagmins; eight of these bind Ca2+ via their C2-domains (Syt1-Syt3, Syt5-7, Syt9, and Syt10), whereas the other eight, including Syt15, do not [].Unlike other synaptotagmins, the mouse and human Syt15 have an alternative splicing isoform that lacks the C-terminal portion of the C2B domain (named Syt15-b). Expression of Syt15 is mainly found in non-neuronal tissues [].
