自催化子单元处理对在20S蛋白质组中形成活性位点,直到组装完成
1Department of Biochemistry and Molecular Biology, The University of Chicago, Illinois 60637, USA.
Cell
|September 20, 1996
概括
酵母 Doa3 蛋白质是酵母中的 Doa3 蛋白质.
科学领域:
- 细胞生物学 细胞生物学
- 蛋白质降解 蛋白质降解
- 分子机制的分子机制
背景情况:
- 欧核生物20S蛋白质酶对细胞蛋白质降解至关重要.
- 蛋白酶体的组装过程和活性位形成尚未完全理解.
- 酵母Doa3蛋白,是一种蛋白酶子单元,作为前体合成.
研究的目的:
- 阐明N端在Doa3结合和蛋白酶组合中的作用.
- 为了研究20S蛋白质组中活性位点成熟的机制.
- 了解蛋白质酶生物发生过程中蛋白质分解位形成的调节.
主要方法:
- 使用酵母模型研究了Doa3的纳入蛋白质组.
- 分析了蛋白质酶组装中的N端的功能.
- 研究了的加工及其对活性位点成熟的影响.
- 检查了前体的自催化处理及其对蛋白酶体粒子协会的依赖.
主要成果:
- Doa3 的 N-终端是它被纳入蛋白酶体的必不可少的,并且在转基因中起作用,这表明它具有伴侣类型的作用.
- 蛋白质酶组合不需要的处理,但对于特定活性位点的成熟至关重要.
- 成熟的Doa3的N终端氨酸可能是这些活性位点的核友.
- 前体处理是自催化性的,需要蛋白质酶半体的关联,防止过早的活性部位形成.
结论:
- Doa3的N终端在蛋白质酶生物发生过程中发挥着关键作用,作为一个陪伴者.
- 蛋白质酶组合和活性位点成熟是通过处理调节的不同的过程.
- 自催化处理,再加上粒子结合,确保了受控的蛋白质溶解部位的形成,保护细胞完整性.
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