Identification of Tim40 that mediates protein sorting to the mitochondrial intermembrane space
Identification of Tim40 that mediates protein sorting to the mitochondrial intermembrane space
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DOI：
10.1074/jbc.m410272200
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发表时间：
2004-11-12
影响因子：
4.8
通讯作者：
Endo, T
中科院分区：
文献类型：
--
作者：
Naoe, M;Ohwa, Y;Endo, T
大多数线粒体蛋白质在胞质溶胶中合成，输入线粒体，并分类到四个线粒体亚室之一。在这里，我们确定了一个新的内膜蛋白，蒂姆40，介导的小蒂姆蛋白的分选到膜间空间。Tim 40是酵母细胞生长所必需的，并且其在体内的功能需要六个保守的Cys残基，但不通过其N-末端疏水片段将蛋白质锚定到内膜。在体内和体外，Tim 40的消耗损害小Tim蛋白进入线粒体的进口。在野生型线粒体中，Tim 40与小Tim蛋白在体外膜间隙组装之前形成易位中间体。这些结果表明Tim 40在小Tim蛋白的分选/组装中的重要作用。
Most mitochondrial proteins are synthesized in the cytosol, imported into mitochondria, and sorted to one of the four mitochondrial subcompartments. Here we identified a new inner membrane protein, Tim40, that mediates sorting of small Tim proteins to the intermembrane space. Tim40 is essential for yeast cell growth, and its function in vivo requires six conserved Cys residues but not anchoring of the protein to the inner membrane by its N-terminal hydrophobic segment. Depletion of Tim40 impairs the import of small Tim proteins into mitochondria both in vivo and in vitro. In wild-type mitochondria, Tim40 forms a translocation intermediate with small Tim proteins prior to their assembly in the intermembrane space in vitro. These results suggest the essential role of Tim40 in sorting/assembly of small Tim proteins.