文章基本信息

标题：The ionic layer is required for efficient dissociation of the SNARE complex by α-SNAP and NSF
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作者：Suzie J. Scales ; Bryan Y. Yoo ; Richard H. Scheller 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2001
卷号：98
期号：25
页码：14262-14267
DOI：10.1073/pnas.251547598
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The four-helical bundle soluble N-ethylmaleimide-sensitive fusion protein (NSF) attachment protein receptor (SNARE) complex that mediates intracellular membrane fusion events contains a highly conserved ionic layer at the center of an otherwise hydrophobic core. This layer has an undetermined function; it consists of glutamine (Q) residues in syntaxin and the two synaptosomal-associated protein of 25 kDa (SNAP-25) family helices, and an arginine (R) in vesicle-associated membrane protein (a 3Q:1R ratio). Here, we show that the ionic-layer glutamine of syntaxin is required for efficient -SNAP and NSF-mediated dissociation of the complex. When this residue is mutated, the SNARE complex still binds to -SNAP and NSF and is released through ATP hydrolysis by NSF, but the complex no longer dissociates into SNARE monomers. Thus, one function of the ionic layer--in particular, the glutamine of syntaxin--is to couple ATP hydrolysis by NSF to the dissociation of the fusion complex. We propose that -SNAP and NSF drive conformational changes at the ionic layer through specific interactions with the syntaxin glutamine, resulting in the dissociation of the SNARE complex.