SNARE complex (Soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex) (SNARE complex)

The SNARE (Soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex is the essential molecular machinery that mediates the exocytosis of acetylcholine at cholinergic nerve terminals, including the neuromuscular junction and autonomic synapses (Südhof, 2013, Neuron). This machinery consists of a core heterotrimeric complex formed by the vesicle-bound protein synaptobrevin (VAMP) and the plasma membrane proteins syntaxin-1 and SNAP-25 (UniProt P60880, P32851, P63027). During neurotransmission, these proteins assemble into a stable four-helix bundle that drives the fusion of the synaptic vesicle membrane with the presynaptic membrane, allowing for the rapid release of acetylcholine into the synaptic cleft (Jahn & Scheller, 2006, Nature Reviews Molecular Cell Biology). This machinery is the specific pharmacological target of Botulinum neurotoxins (BoNTs), which are potent zinc-dependent endopeptidases. BoNT serotypes A, C, and E cleave SNAP-25; serotypes B, D, F, and G cleave VAMP; and serotype C also cleaves syntaxin (StatPearls, 2023). By proteolytically degrading these components, the toxins prevent the formation of the SNARE complex, thereby inhibiting acetylcholine release and causing localized muscle paralysis or reduced glandular secretion. This mechanism is widely utilized in clinical practice to treat various neuromuscular and autonomic disorders, such as dystonia, spasticity, and hyperhidrosis (Dressler et al., 2021, Journal of Neural Transmission).

Other names

SNARE-mediated acetylcholine exocytosis machinerySynaptic SNARE complexNeuronal SNARE machinerySNAP receptor complexVAMP/Syntaxin/SNAP-25 complex

Inhibition of acetylcholine release via site-specific proteolytic cleavage of SNARE proteins (SNAP-25, VAMP/synaptobrevin, or syntaxin), which prevents the assembly of the fusion complex required for synaptic vesicle docking and exocytosis.