Involved in the targeting and/or fusion of transport vesicles to their target membrane. Interacts with VAPA and VAPB. Nervous system, skeletal muscle and adipose tissue. (Microbial infection) Targeted and hydrolyzed by C.botulinum neurotoxin type B (BoNT/B, botB) which probably hydrolyzes the 78-Gln-|-Phe-79 bond and inhibits neurotransmitter release (PubMed:22289120). (Microbial infection) Targeted and hydrolyzed by C.botulinum neurotoxin type D (BoNT/D, botD) which probably hydrolyzes the 61-Arg-|-Leu-62 bond and inhibits neurotransmitter release (PubMed:22289120). BoNT/D has low catalytic activity on this protein due to its sequence (PubMed:22289120). Note that humans are not known to be infected by C.botulinum type D. (Microbial infection) Targeted and hydrolyzed by C.botulinum neurotoxin type F (BoNT/F, botF) which probably hydrolyzes the 60-Gln-|-Lys-61 bond and inhibits neurotransmitter release (PubMed:22289120). (Microbial infection) Targeted and hydrolyzed by C.botulinum neurotoxin type X (BoNT/X) which probably hydrolyzes the 68-Arg-|-Ala-69 bond and inhibits neurotransmitter release (PubMed:29540745). It remains unknown whether BoNT/X is ever produced, or what organisms it targets. The disease is caused by variants affecting the gene represented in this entry. A mutation affecting a critical donor site for the splicing of VAMP1 isoforms leads to the loss of neuron-specific isoform 1 and subsequently results in haploinsufficiency (PubMed:22958904). Therefore, there would be less neurotransmitter exocytosis in specific regions of the brain, causing the symptoms of SPAX1. The disease is caused by variants affecting the gene represented in this entry. Belongs to the synaptobrevin family.