Processive ATP - driven Substrate Disassembly by the N - Ethylmaleimide - sensitive Factor ( NSF ) Molecular
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چکیده
Background: NSF is an AAA protein that recycles the post-fusion SNARE complex during the membrane fusion cycle. Results: NSF disassembles the SNARE complex processively in vitro and consumes dozens of ATP molecules per SNARE. Conclusion: NSF is a processive motor that progressively unwinds the SNARE complex. Significance: The physical mechanism of this poorly understood machine is illuminated using new assays and new measurements of ATP coupling ratios and processivity.
منابع مشابه
Processive ATP-driven Substrate Disassembly by the N-Ethylmaleimide-sensitive Factor (NSF) Molecular Machine*♦
SNARE proteins promote membrane fusion by forming a four-stranded parallel helical bundle that brings the membranes into close proximity. Post-fusion, the complex is disassembled by an AAA+ ATPase called N-ethylmaleimide-sensitive factor (NSF). We present evidence that NSF uses a processive unwinding mechanism to disassemble SNARE proteins. Using a real-time disassembly assay based on fluoresce...
متن کاملSpring-loaded unraveling of a single SNARE complex by NSF in one round of ATP turnover.
During intracellular membrane trafficking, N-ethylmaleimide-sensitive factor (NSF) and alpha-soluble NSF attachment protein (α-SNAP) disassemble the soluble NSF attachment protein receptor (SNARE) complex for recycling of the SNARE proteins. The molecular mechanism by which NSF disassembles the SNARE complex is largely unknown. Using single-molecule fluorescence spectroscopy and magnetic tweeze...
متن کاملThree αSNAP and 10 ATP molecules are used in SNARE complex disassembly by N-ethylmaleimide-sensitive factor (NSF).
The fusion of intracellular membranes is driven by the formation of a highly stable four-helix bundle of SNARE proteins embedded in the vesicle and target membranes. N-Ethylmaleimide sensitive factor recycles SNAREs after fusion by binding to the SNARE complex through an adaptor protein, αSNAP, and using the energy of ATP hydrolysis to disassemble the complex. Although only a single molecule of...
متن کاملA conserved membrane attachment site in alpha-SNAP facilitates N-ethylmaleimide-sensitive factor (NSF)-driven SNARE complex disassembly.
The ATPase NSF (N-ethylmaleimide-sensitive factor) and its SNAP (soluble N-ethylmaleimide-sensitive factor attachment protein) cofactor constitute the ubiquitous enzymatic machinery responsible for recycling of the SNARE (SNAP receptor) membrane fusion machinery. The enzyme uses the energy of ATP hydrolysis to dissociate the constituents of the SNARE complex, which is formed during the fusion o...
متن کاملThe Role of the N-D1 Linker of the N-Ethylmaleimide-Sensitive Factor in the SNARE Disassembly
N-ethylmaleimide-sensitive factor (NSF) is a member of the type II AAA+ (ATPase associated with various cellular activities) family. It plays a critical role in intracellular membrane trafficking by disassembling soluble NSF attachment protein receptor (SNARE) complexes. Each NSF protomer consists of an N-terminal domain (N domain) followed by two AAA ATPase domains (D1 and D2) in tandem. The N...
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