Synaptobrevin

Synaptobrevins (synaptobrevin isotypes 1-2) are small integral membrane proteins of secretory vesicles with molecular weight of 18 kilodalton (kDa) that are part of the vesicle-associated membrane protein (VAMP) family.

Synaptobrevin is one of the SNARE proteins involved in formation of the SNARE complexes. Out of four α-helices of the core SNARE complex one is contributed by synaptobrevin, one by syntaxin, and two by SNAP-25 (in neurons).

SNARE proteins are the key components of the molecular machinery that drives fusion of membranes in exocytosis. Their function however is subject to fine tuning by various regulatory protein collectively referred to as SNARE masters.

Because all proteins belonging to VAMP/synaptobrevin family share common structural feature, they have been classified as R-SNAREs. An alternative classification (v- and t-SNAREs) exists that takes into account origin of synaptobrevin-bearing organelle rather than their structural properties.

Synaptobrevin is degraded by Tetanospasmin, a protein derived from Clostridium tetani.