Synaptotagmin-13 (SYT13) 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 (transmembrane region) that is involved in membrane anchoring or specific ligand binding. Unlike most of the synaptotagmins, SYT13 does not have an N-terminal transmembrane region. Its C2 domains are lacking almost all the residues involved in Ca2+ binding []. It is highly expressed in brain and also detectable at lower levels in non-neuronal tissues []. SYT13 can suppress liver tumour cells and this function may be mediated through pathways implicated in mesenchymal to epithelial transition []. It also affects insulin secretion [].
