在SNARE拆卸时,需要Sec18/NSF侧载荷
Yousuf A Khan1,2,3,4, K Ian White5,6,7,8,9, Richard A Pfuetzner5,6,7,8,9
1Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA. yousuf@stanford.edu.
Nature structural & molecular biology
|July 3, 2025
概括
在细胞膜融合后,Sec18/NSF (N-乙烯胺胺敏感因子) 和Sec17/α-SNAP将SNARE蛋白束分解. 新的冷-EM结构显示Sec18/NSF线索通过其ATPase环通过SNAREs,使侧载和卸载成为可能.
科学领域:
- 细胞生物学 细胞生物学
- 分子机器的分子机器.
- 膜融合是什么? 膜融合是什么?
背景情况:
- 通过形成四螺旋,SNARE蛋白调解了膜融合.
- 在Sec18/NSF和Sec17/α-SNAP中将这些捆拆为回收使用.
- 之前的模型面临着SNARE跨膜域的拓挑战.
研究的目的:
- 通过Sec18/NSF阐明SNARE复合体拆解的机制.
- 解决SNARE通过Sec18/NSF线程的拓约束.
- 为了可视化Sec18/NSF和Sec17/α-SNAP与SNAREs的相互作用.
主要方法:
- 酵母SNARE复合物的冷电子显微镜 (冷EM).
- 质谱测量以确定蛋白质相互作用.
- 在非水解和水解条件下进行结构分析.
主要成果:
- 化EM结构显示SNARE Sso1通过Sec18/NSF的D1和D2 ATPase环进行线索.
- Sso1 的 N-终端 Habc 域与 D2 环相互作用,并保持折叠.
- 在水解条件下的结构显示基质释放和环开放.
- 在Sec18/NSF中,用于拓上受约束的SNARE,使用侧面加载和卸载.
结论:
- Sec18/NSF通过侧载机制将SNARE拆卸.
- Sec18/NSF的ATPase环开放以容纳和释放SNARE基质.
- 这种机制克服了SNARE域所带来的拓约束.
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