Vesicle-associated membrane protein-2 (synaptobrevin-2) forms a complex with synaptophysin.
Vesicle-associated membrane protein (VAMP) (or synaptobrevin), a type II membrane protein of small synaptic vesicles, is essential for neuroexocytosis because its proteolysis by tetanus and botulinum neurotoxins types B, D, F and G blocks neurotransmitter release. The addition of cross-linking reagents to isolated small synaptic vesicles induces the formation of 30 and 50 kDa complexes containing the isoform 2 of VAMP (VAMP-2). Whereas the 30 kDa band is a VAMP-2 homodimer, the 50 kDa species results from the cross-linking of VAMP-2 with synaptophysin. This heterodimer also forms in detergent-solubilized vesicles and involves the N-terminal part of VAMP-2. The implications of the existence of a synaptophysin-VAMP-2 complex in the processes of vesicle docking and fusion with the presynaptic membrane are discussed.
Centro CNR Biomembrane, Università di Padova, Italy.
P
P
Washbourne
G
G
Schiavo
C
C
Montecucco
D000595:Amino Acid Sequence; D000818:Animals; D002540:Cerebral Cortex / Q000648:ultrastructure; D002645:Chickens; D003432:Cross-Linking Reagents / Q000494:pharmacology; D015151:Immunoblotting; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D050683:R-SNARE Proteins; D051381:Rats; D013572:Synaptic Vesicles / Q000378:metabolism*; D016708:Synaptophysin / Q000378:metabolism*
D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D050683:R-SNARE Proteins; D016708:Synaptophysin