POLYPEPTIDES TRAVERSE THE MITOCHONDRIAL ENVELOPE IN AN EXTENDED STATE
POLYPEPTIDES TRAVERSE THE MITOCHONDRIAL ENVELOPE IN AN EXTENDED STATE
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DOI：
10.1016/0014-5793(90)81469-5
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发表时间：
1990-11-26
期刊：
影响因子：
3.5
通讯作者：
NEUPERT, W
中科院分区：
文献类型：
--
作者：
RASSOW, J;HARTL, FU;NEUPERT, W
大多数线粒体蛋白质作为前体在胞质溶胶中合成，并通过线粒体外膜和内膜之间的接触位点输入。前体蛋白膜转位的分子机制在很大程度上还不清楚。在本报告中，细胞色素b 2前体部分和整个二氢叶酸还原酶（DHFR）之间的各种杂合蛋白在线粒体接触位点积累。我们意外地发现，转运中的多肽链的约30个氨基酸残基足以跨越两个膜。这表明多肽链的线性易位，并提供了穿越线粒体膜的多肽高度展开的证据。
Most mitochondrial proteins are synthesized as precursors in the cytosol and imported through the contact sites between outer and inner mitochondrial membranes. The molecular mechanism of membrane translocation of precursor proteins is largely unclear. For this report, various hybrid proteins between portions of the precursor of cytochromeb2and the entire dihydrofolate reductase (DHFR) were accumulated in mitochondrial contact sites. We unexpectedly found that about 30 amino acid residues of the polypeptide chain in transit were sufficient to span both membranes. This suggests linear translocation of the polypeptide chain and presents evidence for a high degree of unfolding of polypeptides traversing the mitochondrial membranes.