Showing papers by "Thomas Binz published in 1995"
TL;DR: It is shown that this reconstituted complex, as well as heterodimers composed of syntaxin and SNAP‐25, can be disassembled by the concerted action of the N‐ethylmaleimide‐sensitive factor, NSF, and the soluble NSF attachment protein, alpha‐SNAP.
Abstract: The interaction of the presynaptic membrane proteins SNAP-25 and syntaxin with the synaptic vesicle protein synaptobrevin (VAMP) plays a key role in the regulated exocytosis of neurotransmitters. Clostridial neurotoxins, which proteolyze these polypeptides, are potent inhibitors of neurotransmission. The cytoplasmic domains of the three membrane proteins join into a tight SDS-resistant complex (Hayashi et al., 1994). Here, we show that this reconstituted complex, as well as heterodimers composed of syntaxin and SNAP-25, can be disassembled by the concerted action of the N-ethylmaleimide-sensitive factor, NSF, and the soluble NSF attachment protein, alpha-SNAP. alpha-SNAP binds to predicted alpha-helical coiled-coil regions of syntaxin and SNAP-25, shown previously to be engaged in their direct interaction. Synaptobrevin, although incapable of binding alpha-SNAP individually, induced a third alpha-SNAP binding site when associated with syntaxin and SNAP-25 into heterotrimers. NSF released prebound alpha-SNAP from full-length syntaxin but not from a syntaxin derivative truncated at the N-terminus. Disassembly of complexes containing this syntaxin mutant was impaired, indicating a critical role for the N-terminal domain in the alpha-SNAP/NSF-mediated dissociation process. Complexes containing C-terminally deleted SNAP-25 derivatives, as generated by botulinal toxins type A and E, were dissociated more efficiently. In contrast, the N-terminal fragment generated from synaptobrevin by botulinal toxin type F produced an SDS-sensitive complex that was poorly dissociated.
259 citations