Requirements for the catalytic cycle of the N-ethylmaleimide-Sensitive Factor (NSF)

详细信息    查看全文

• 作者：Chunxia Zhao¹ ; ^{chz024@ucsd.edu} ; Everett C. Smith ; Sidney W. Whiteheart ; ^{whitehe@uky.edu}
• 关键词：NSF ; N-ethylmaleimide sensitive factor ; AAA+ ; ATPases Associated with various cellular Activities plus ; SNAP ; Soluble NSF Attachment Protein ; SNARE ; SNAP-binding Receptor ; ESCRT ; Endosomal Sorting Complexes Required for Transport ; AMP-PNP ; non-hydrolyzabl
• 刊名：Biochimica et Biophysica Acta (BBA)/Molecular Cell Research
• 出版年：2012
• 出版时间：January 2012
• 年：2012
• 卷：1823
• 期：1
• 页码：159-171
• 全文大小：1549 K

文摘

The N-ethylmaleimide-Sensitive Factor (NSF) was one of the initial members of the ATPases Associated with various cellular Activities Plus (AAA⁺) family. In this review, we discuss what is known about the mechanism of NSF action and how that relates to the mechanisms of other AAA⁺ proteins. Like other family members, NSF binds to a protein complex (i.e., SNAP-SNARE complex) and utilizes ATP hydrolysis to affect the conformations of that complex. SNAP-SNARE complex disassembly is essential for SNARE recycling and sustained membrane trafficking. NSF is a homo-hexamer; each protomer is composed of an N-terminal domain, NSF-N, and two adjacent AAA-domains, NSF-D1 and NSF-D2. Mutagenesis analysis has established specific roles for many of the structural elements of NSF-D1, the catalytic ATPase domain, and NSF-N, the SNAP-SNARE binding domain. Hydrodynamic analysis of NSF, labeled with (Ni²⁺-NTA)₂-Cy3, detected conformational differences in NSF, in which the ATP-bound conformation appears more compact than the ADP-bound form. This indicates that NSF undergoes significant conformational changes as it progresses through its ATP-hydrolysis cycle. Incorporating these data, we propose a sequential mechanism by which NSF uses NSF-N and NSF-D1 to disassemble SNAP-SNARE complexes. We also illustrate how analytical centrifugation might be used to study other AAA⁺ proteins. This article is part of a Special Issue entitled: AAA ATPases: structure and function.