The 25 kDa synaptosome-associated protein (SNAP25) is a target membrane soluble, N-ethylmaleimide-sensitive factor attachment protein receptor (t-SNARE) that is found on neuronal presynaptic membranes. SNAP25 forms a core complex with the SNARE proteins syntaxin and synaptobrevin to mediate synaptic vesicle fusion with the plasma membrane during Ca2+-dependent exocytosis (1). This complex is responsible for exocytosis of the neurotransmitter γ-aminobutyric acid (GABA). Neurotransmitter release is inhibited by proteolysis of SNAP25 by botulinum toxins A and E (2). SNAP25 plays a secondary role as a Q-SNARE involved in endosome fusion; the protein is associated with genetic susceptibility to attention-deficit hyperactivity disorder (ADHD) (3).
