A synaptic vesicle membrane protein is conserved from mammals to Drosophila.

The structure of synaptobrevin, an intrinsic membrane protein of small synaptic vesicles from mammalian brain, was studied by purification and molecular cloning. Its message in bovine brain encodes a 116 amino acid protein whose sequence reveals it to be the mammalian homolog of Torpedo VAMP-1. Antibody probing demonstrates that the protein is also present in Drosophila, and its Drosophila homolog was cloned. Alignment of the sequences of synaptobrevin/VAMP-1 from the three species shows it to contain four domains, including a highly conserved central region of 63 amino acids that contains 75% invariant residues. The finding that a membrane protein from vertebrate synaptic vesicles is conserved in Drosophila points toward a central role of this protein in neurotransmission and should allow a genetic approach to neurotransmitter release.