VAMP7

VAMP7, also known as TI-VAMP (tetanus toxin-insensitive vesicle–associated membrane protein 7), is a member of the SNARE protein family that mediates membrane fusion events in cells. It is expressed in many tissues and participates in secretory and trafficking pathways, notably in neurons, glandular cells, and immune cells.

Structurally, VAMP7 is a vesicle-associated protein anchored in membranes by a C-terminal transmembrane domain. It contains an N-terminal longin domain, which helps regulate trafficking and targeting, followed by a central SNARE motif that participates in complex formation with target-m membrane SNAREs during fusion.

In the fusion machinery, VAMP7 functions as a vesicle (v-)SNARE that pairs with appropriate target-membrane (t-)SNAREs to drive membrane fusion. In late endosome–lysosome trafficking, it commonly partners with Q-SNAREs such as syntaxin 7 and Vti1b to promote fusion events. The activity of VAMP7 can be regulated by SM proteins, including members of the Munc18 family, which influence SNAREassembly and vesicle docking.

Functional roles of VAMP7 include participation in constitutive and regulated exocytosis, endocytosis and lysosomal trafficking, and neurite outgrowth in neurons. In the nervous system, it contributes to vesicle transport and secretion in growth cones and synaptic-like structures. In other cell types, VAMP7 supports trafficking to lysosomes and secretory pathways, enabling proper cargo delivery and membrane turnover.

Research on VAMP7 continues to define its specific SNARE partners across cell types and its regulation by accessory proteins. Alterations in VAMP7-mediated trafficking can impact cellular homeostasis and have been studied in the context of development and neurobiology.