Synaptosomal-associated protein 25 kDa (SNAP-25)

SNAP-25 is a membrane-associated SNARE protein essential for the calcium-triggered exocytosis of synaptic vesicles at chemical synapses, including cholinergic terminals. It forms a complex with syntaxin-1 and synaptobrevin/VAMP, mediating fusion of neurotransmitter-filled vesicles with the presynaptic membrane to enable acetylcholine release. Absence or cleavage of SNAP-25 abolishes fast synaptic exocytosis. Phosphorylation of SNAP-25 by PKA modulates its activity and synaptic plasticity. SNAP-25 is implicated in several neurological and psychiatric disorders, and is the molecular target of botulinum neurotoxins, which cause neuroparalysis by blocking neurotransmitter release. SNAP-25 is expressed at presynaptic terminals of both cholinergic and other types of neurons (glutamatergic, GABAergic), but is especially well-studied in cholinergic transmission at the neuromuscular junction and central synapses. Its function and post-translational modifications (e.g., phosphorylation, acetylation) shape synaptic efficacy, plasticity, and may underlie disease states or therapeutic mechanisms.

Other names

SNAP25Synaptosomal-associated protein 25t-SNARESN25SuP

Inhibition (botulinum neurotoxins cleave SNAP-25, blocking neurotransmitter release and causing paralysis); Modulation of SNARE complex stability via phosphorylation (PKA-mediated)