Hsp90,DnaK和ClpB在蛋白质活性化过程中进行协作
Joel R Hoskins1, Anushka C Wickramaratne1, Connor P Jewell2
1Laboratory of Molecular Biology, National Cancer Institute, NIH, Bethesda, MD 20892.
概括
像Hsp70,Hsp90和ClpB这样的分子伴侣维持蛋白质静止. 这项研究表明,大肠杆菌Hsp90 (Hsp90Ec) 与DnaK和ClpB合作,分解和重新激活蛋白质,即使在高DnaK度下也是如此.
科学领域:
- 分子生物学分子生物学
- 蛋白质的生物化学 蛋白质的生物化学
- 细胞平衡是细胞的平衡.
背景情况:
- 分子伴侣,包括Hsp70,Hsp90和ClpB/Hsp100,对于维持蛋白质静止至关重要.
- Hsp70和Hsp90的功能是协同的,以重新激活蛋白质,需要直接相互作用.
- 涉及Hsp70和ClpB/Hsp104的双系统分解蛋白质和粉样蛋白,也取决于直接相互作用.
研究的目的:
- 调查大肠杆菌的同类DnaK (Hsp70),Hsp90Ec (Hsp90) 和ClpB,以及DnaJ和GrpE的共,是否可以促进蛋白质分解和重新激活.
- 确定Hsp90Ec和ClpB在基于DnaK的系统中的作用,特别是在限制DnaK度的条件下.
主要方法:
- 利用体外测试来评估DnaK,Hsp90Ec,ClpB,DnaJ和GrpE的联合活性.
- 研究了ATP水解和基质结合对于伴侣功能的必要性.
- 在蛋白质重新激活过程中分析了伴侣作用的时间顺序.
主要成果:
- 在高度下,Hsp90Ec有效地克服了DnaK的抑制,促进了蛋白质分解和重新激活.
- 通过DnaK,Hsp90Ec和ClpB进行ATP水解和基质结合,对于它们的协作功能至关重要.
- 在重新激活过程中,ClpB的功能很早就开始了,随后的阶段是Hsp90Ec.
结论:
- DnaK,Hsp90Ec和ClpB的组合,以及cochaperones,可以有效地管理蛋白质分解和重新激活.
- Hsp90Ec在提高护送系统效率方面发挥着至关重要的作用,特别是在DnaK丰富的情况下.
- 这些发现强调了陪伴者协作在维持细胞蛋白质稳定中的重要性.
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