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

The presynaptic cholinergic nerve terminal SNARE (Soluble N-ethylmaleimide-sensitive factor attachment protein receptor) exocytosis machinery is a specialized protein complex responsible for the release of acetylcholine into the neuromuscular junction and autonomic synapses (Jahn & Scheller, 2006). It primarily consists of three key proteins: synaptobrevin (also known as vesicle-associated membrane protein or VAMP) on the vesicle membrane, and syntaxin-1 and SNAP-25 on the presynaptic plasma membrane (Rossetto et al., 2014). These proteins assemble into a stable four-helix bundle that pulls the vesicle and plasma membranes into close proximity, facilitating membrane fusion and subsequent neurotransmitter exocytosis. This machinery is the primary target for botulinum neurotoxins (BoNTs), which act as highly specific zinc-dependent endopeptidases (Dressler et al., 2005). By cleaving specific components of the SNARE complex—such as SNAP-25 by BoNT/A or synaptobrevin by BoNT/B—these toxins prevent the formation of the fusion complex, effectively blocking cholinergic transmission (Dhaked et al., 2010). This mechanism is therapeutically exploited to treat conditions characterized by muscle overactivity, such as cervical dystonia, spasticity, and chronic migraine, as well as for cosmetic applications.

Other names

Synaptic fusion complexVAMP/Syntaxin/SNAP-25 complexExocytosis machineryPresynaptic SNARE complex

Proteolytic cleavage of SNARE proteins (SNAP-25, Syntaxin, or VAMP), preventing the formation of the SNARE complex and inhibiting acetylcholine release.