在组装质量控制过程中识别孤儿子单位的机制
Yuichi Yagita1, Eszter Zavodszky1, Sew-Yeu Peak-Chew1
1MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
Cell
|July 22, 2023
概括
研究人员确定了细胞如何识别和降解细胞中 Chaperonin CCT (含有 Chaperonin 的 T 复合物 1) 的孤儿子单元. 在这种关键的细胞质量控制过程中,E3泛素连接酶HERC2和适配器ZNRD2是关键.
科学领域:
- 细胞生物学
- 分子机制
- 蛋白质质量控制
背景情况:
- 细胞从多个子单元组建复杂的分子机器.
- 生产失衡或组装故障导致孤儿子单位,这些子单位通过不太了解的途径降解.
- 细胞质沙佩罗宁CCT是一个大型的,必不可少的多个子单元组件.
研究的目的:
- 阐明细胞性沙佩罗宁CCT的孤儿子单元被识别并被向降解的分子机制.
- 确定未组装的CCT子单位的质量控制途径所涉及的因素.
主要方法:
- 使用未组装的CCT子单元,E3无素连接酶HERC2和适配器ZNRD2进行招募测试.
- 细胞降解试验以评估HERC2和ZNRD2的必要性.
- 用纯化的因子进行体外无化试验.
- 对HERC2-ZNRD2-CCT交互模块进行域映射和结构预测.
- 使用细胞中的点突变对结构模型预测的验证.
主要成果:
- 孤儿CCT子单元通过适应蛋白ZNRD2招募E3无素连接酶HERC2.
- HERC2和ZNRD2对于细胞中孤儿CCT亚单元的降解至关重要.
- 纯化的HERC2和ZNRD2足以在体外无处不在的CCT子单元.
- 一个结构模型揭示了ZNRD2如何选择性地结合多个孤儿CCT子单元而不识别组装的CCT.
- HERC2-ZNRD2-CCT模块对于细胞的最佳适应性至关重要.
结论:
- HERC2-ZNRD2复合体作为未组装的CCT子单元的传感器,标记它们的降解.
- 这项研究揭示了识别孤儿子单位的特定分子机制,这是细胞质量控制基质的主要来源.
- 这些发现为了解其他多个子单元蛋白质复合体中孤儿子单元的识别提供了一个范式.
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