Synaptosome-associated protein 25 (SNAP-25) (SNAP-25)

Synaptosome-associated protein 25 (SNAP-25) is a critical t-SNARE protein located on the presynaptic membrane of neurons, where it plays a fundamental role in the fusion of synaptic vesicles and the subsequent release of neurotransmitters like acetylcholine [1, 3]. It functions by forming a four-helix bundle with syntaxin-1 and synaptobrevin, which pulls the vesicle toward the plasma membrane in response to calcium influx [1]. SNAP-25 is the specific intracellular target for Botulinum neurotoxin type A (BoNT/A), which gains entry into cholinergic neurons by binding to presynaptic receptors such as Synaptic Vesicle protein 2 (SV2) and gangliosides [2, 3]. Once inside, the toxin's light chain cleaves SNAP-25, effectively disabling the SNARE machinery and blocking neuromuscular transmission [2]. This mechanism is therapeutically exploited to treat a wide range of conditions characterized by muscular overactivity or autonomic dysfunction, including cervical dystonia, chronic migraine, and hyperhidrosis [2, 3]. Clinical efficacy is monitored through the reduction of muscle activity, while safety concerns primarily involve the potential for the toxin to spread beyond the injection site [2].

Other names

SNAP25Synaptosomal-associated 25 kDa proteinSuperproteinRIC-4RIC4

Proteolytic cleavage of SNAP-25 by the light chain of Botulinum neurotoxin type A, which prevents the formation of the SNARE complex and inhibits the release of acetylcholine from presynaptic terminals [2, 3].