在ERAD中的关键步骤是用净化组件复制的光ER蛋白质
Alexander Stein1, Annamaria Ruggiano2, Pedro Carvalho2
1Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
Cell
|September 13, 2014
概括
这项研究揭示了错误折叠的ER蛋白如何被输送到细胞质中进行降解. Hrd1p结合酶形成了一个导体,Cdc48p提取无处不在的蛋白质用于蛋白质体处理.
科学领域:
- 细胞生物学 细胞生物学
- 蛋白质降解 蛋白质降解
- 细胞内膜网膜应激压力
背景情况:
- 错误折叠的内质网膜 (ER) 蛋白质是通过ER相关蛋白质降解 (ERAD) 降解的目标.
- 在ERAD中涉及到回转移到细胞质中,聚基化和蛋白质体降解.
- 精确的ERAD分子机制,特别是对于光基板 (ERAD-L),仍然不完全理解.
研究的目的:
- 为了阐明使用纯化组件的光基质 (ERAD-L) 与ER相关的蛋白质降解的机制.
- 描述乌比基因酶Hrd1p在基质识别和逆转移中的作用.
- 在ERAD途径中划分Cdc48p ATPase复合体和Otu1p二基化酶的功能.
主要方法:
- 使用来自Saccharomyces cerevisiae的纯化蛋白质进行ERAD-L逆转移的复制.
- 生物化学试验分析蛋白质与蛋白质相互作用和酶活性.
- 使用复制的蛋白质体来研究聚比基化蛋白质的膜提取.
主要成果:
- 唯一需要的膜蛋白Hrd1p通过其膜跨域与错误折叠的基板相互作用,使其与折叠蛋白区分开来.
- 无论是Hrd1p还是基质都经历了多基化,促进了Cdc48p ATPase复合物的招募.
- 通过Cdc48p介导的ATP水解会从Hrd1p释放基质,而Otu1p在Cdc48p的招募和激活时会削减ubiquitin链.
结论:
- Hrd1p 作为膜导体,促进了 ER 光线中错误折叠的蛋白质的逆转移.
- Hrd1p,Cdc48p和Otu1p的协调作用推动了错误折叠的ER蛋白的高效提取和降解.
- 这项研究提供了ERAD-L的机制模型,突出了Hrd1p在基质选择和转移中的核心作用.
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