线粒体的伴侣素hsp60是需要自己的组装
M Y Cheng1, F U Hartl, A L Horwich
1Howard Hughes Medical Institute, Department of Human Genetics, Yale School of Medicine, New Haven, Connecticut 06510.
Nature
|November 29, 1990
概括
在线粒体中的热冲击蛋白60 (hsp60) 组装需要先前存在的复合体. 这表明蛋白质折叠机制本身需要指导才能在细胞内形成正确的结构.
科学领域:
- 线粒体生物学 线粒体生物学
- 蛋白质折叠过程中的蛋白质折叠
- 分子的伴侣是分子的伴侣.
背景情况:
- 热冲击蛋白60 (hsp60) 对于线粒体内的蛋白质折叠至关重要.
- Hsp60作为一个伴侣蛋白,形成14-mer复合物,对蛋白质组合至关重要.
- hsp60复杂组件本身的机制仍然不清楚.
研究的目的:
- 为了研究热冲击蛋白60 (hsp60) 综合体的组装机制.
- 要确定hsp60子单元是否可以自组装或需要现有结构.
主要方法:
- 研究了一种在hsp60.0.中缺陷的酵母突变 (mif4) 中的hsp60组合.
- 在完整的细胞和孤立的线粒体中观察到野生型hsp60子单元的组装.
- 在体外分析进口hsp60子单元的组装动力学.
主要成果:
- 新进口的hsp60子单位在hsp60缺陷的酵母突变体中没有自组装.
- 为了组装新的14-mer复合体,需要一个功能性,先前存在的hsp60复合体.
- 在实验室中hsp60子单元的组装发生得很快 (5-10分钟半程时间),表明催化过程.
结论:
- 功能性热冲击蛋白60 (hsp60) 复合物的组装不是一个自发的自我组装过程.
- 需要现有的hsp60结构来促进新进口子单元的组装.
- 这挑战了简单自我组装的概念,作为实现蛋白质构成的主要机制 in vivo.
相关概念视频
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Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
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Mitochondrial Precursor Proteins
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Most of the mitochondrial precursors...
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Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
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Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
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Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
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Molecular Chaperones and Protein Folding
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