A synaptotagmin enriched in synaptosomal membranes
Up to now at least 17 synaptotagmins have been identified. Like other proteins of this family synaptotagmin 3
is composed of a vesicular, a transmembrane and two C2 domains.
Synaptotagmin 3 is expressed in brain, where it localizes to synaptic plasma membranes, and also in non-neuronal cells. In pancreatic islet β-cells it is involved in Ca2+
triggered insulin secretion, and in basophilic leukemia mast cells (RBL-cells) in transport events to the perinuclear endocytic recycling compartment.