一种基于结构的机制,用于启动AP-3涂层囊泡的形成
Matthew Begley1, Mahira Aragon2, Richard W Baker1,3
1Department of Biochemistry and Biophysics, UNC Chapel Hill School of Medicine; Chapel Hill, NC 27516, USA.
bioRxiv : the preprint server for biology
|June 19, 2024
概括
适配蛋白复合体3 (AP-3) 调节货物的分类. 这项研究揭示了AP-3的存在.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 适配蛋白复合体3 (AP-3) 对于蛋白质分类到 lysosomes 和相关细胞器至关重要.
- 与AP-1和AP-2不同,AP-3存在于一个构成性的开放形状,这引发了关于其调节的问题.
- 了解AP-3调控是阐明内体-溶体贩运途径的关键.
研究的目的:
- 研究AP-3膜招募和激活的机制.
- 为了确定在囊泡形成过程中AP-3形状变化的结构基础.
- 阐明Arf1在调节AP-3功能中的作用.
主要方法:
- 人类AP-3核心复合物的重建.
- 电子冷显微镜 (cryo-EM) 用于确定溶性和膜结合状态的结构.
- 用于创建Arf1-AP-3膜结合复合体的脂质纳米盘.
主要成果:
- 人类AP-3保持着构成性开放的形状,具有灵活的货物绑定域.
- 观察到AP-3在Arf1绑定和货物绑定时的逐步形状变化.
- 载荷结合稳定了AP-3,促进了第二次Arf1相互作用,并启动了涂层聚合的二分化.
- 证据表明,AP-3中的两螺旋体在膜变形中发挥了作用.
结论:
- AP-3的激活和外套组装与货物接触密切相关.
- 这种机制确保了有效和规范的货物分类到特定的器官.
- 这些发现为AP-3介导的囊泡层形成和膜贩运的初始阶段提供了洞察力.
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