SNAP-25 can self-associate to form a disulfide-linked complex.
SNAP-25 is expressed in neurons and endocrine cells and is essential for exocytosis of neurotransmitters and peptide hormones. It has been shown to be involved in several interactions with other proteins of the secretion machinery. Here we show that SNAP-25 can self-associate to form a disulfide-linked complex. Complex formation is facilitated in vitro (in concentrated extracts or by immunoprecipitation). SNAP-25 complexes, however, also form when intact cells are treated with a membrane-permeable crosslinker indicating that SNAP-25 molecules exist in close proximity in vivo and could form complexes spontaneously. We also show that monomeric SNAP-25 and disulfide-linked SNAP-25 complexes are palmitoylated and that both can be cleaved by botulinum neurotoxin E.
Sadoul
K
K
Laboratoires de Recherche Louis Jeantet, Centre Médical Universitaire, Geneva, Switzerland.
Berger
A
A
Niemann
H
H
Regazzi
R
R
Catsicas
S
S
Halban
P A
PA
D000818:Animals; D001905:Botulinum Toxins / Q000737:chemistry; D001923:Brain Chemistry; D002463:Cell Membrane Permeability; D003432:Cross-Linking Reagents / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry*; D066298:In Vitro Techniques; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D009474:Neurons / Q000737:chemistry; D011233:Precipitin Tests; D051381:Rats; D050825:Synaptosomal-Associated Protein 25
D003432:Cross-Linking Reagents; D004220:Disulfides; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C494210:Snap25 protein, rat; D050825:Synaptosomal-Associated Protein 25; D001905:Botulinum Toxins; C096326:botulinum toxin type E