侧载Sec18对于跨细胞环境的普遍SNARE回收是必不可少的
Yousuf A Khan1,2,3,4, K Ian White1,2,3,4,5, Richard A Pfuetzner1,2,3,4,5
1Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA.
bioRxiv : the preprint server for biology
|September 11, 2024
概括
在Sec18/NSF (Sec18/N-乙烯胺胺敏感因子) 中,SNARE蛋白质复合体被分解,用于膜融合. 新结构揭示Sec18/NSF使用侧载来处理拓上受约束的SNARE,而不会展开其域.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 蛋白质的结构和功能.
背景情况:
- 通过形成四螺旋,SNARE蛋白调解了膜融合.
- 根据Sec18/NSF (Sec18/N-乙烯胺胺敏感因子) 和Sec17/α-SNAP,将这些捆绑拆卸回收.
- 之前的模型面临着SNARE域和跨膜区域的拓挑战.
研究的目的:
- 阐明Sec18/NSF在拆解SNARE复合体中的机制.
- 通过Sec18/NSF解决SNARE基板线程的拓约束.
- 为了可视化Sec18/NSF在拆卸周期中的结构状态.
主要方法:
- 在体内质谱测试以确定蛋白质相互作用.
- 电子显微镜 (Cryo-EM) 用于确定高分辨率结构.
- 在不同功能状态下对Sec18/NSF-Sec17/α-SNAP-SNARE复合物的结构分析.
主要成果:
- N端 SNARE 域与 Sec18/NSF 相互作用,使线程复杂化.
- 低温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 域保持折叠,并与 D2 环相互作用.
- 在水解条件下的结构显示了基质通过协调环开放释放.
结论:
- Sec18/NSF采用侧载机制,用于引入和拆卸具有拓限制的SNARE基板.
- 在拆卸过程中,SNARE基板不需要完全展开.
- 这种机制允许SNARE蛋白质在随后的膜融合事件中得到有效的回收.
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