Zim17, a novel zinc finger protein essential for protein import into mitochondria
Zim17, a novel zinc finger protein essential for protein import into mitochondria
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DOI：
10.1074/jbc.m409194200
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发表时间：
2004-11-26
影响因子：
4.8
通讯作者：
Lithgow, T
中科院分区：
文献类型：
--
作者：
Burri, L;Vascotto, K;Lithgow, T
前体蛋白跨线粒体膜的易位需要外膜和内膜中多亚基易位酶的协调作用，跨内膜易位的驱动力由位于基质的热休克蛋白70（mtHsp70）提供。蛋白质输入机制的核心部件至关重要。在这里，我们描述了 Zim17，一种必需蛋白，在 otif 下有一个 (ZI)，在 otif 下有一个 (ZI)，参与蛋白质输入线粒体。比较基因组学建议对 YNL310c（酿酒酵母中编码 Zim17 的基因）的开放阅读框进行修正。修订后的开放阅读框编码经典的线粒体靶向信号，该信号由线粒体基质中的 Zim17 进行处理。 Zim17 的缺失选择性地减少了蛋白质向线粒体基质的输入，但这种 Zim17 的缺失被 J 蛋白 Pam18/Tim14 的过度表达部分抑制。我们建议 Zim17 作为“断裂”J 蛋白的一个例子，其中像 Zim17 这样的蛋白为 III 型 J 蛋白提供锌指结构域，从而为 Hsp70 提供底物负载。
Translocation of precursor proteins across the mitochondrial membranes requires the coordinated action of multisubunit translocases in the outer and inner membrane, and the driving force for translocation across the inner membrane is provided by the matrix-located heat shock protein 70 (mtHsp70). The central components of the protein import machinery are essential. Here we describe Zim17, an essential protein with a (ZI) under bar nc finger (M) under bar otif involved in protein import into mitochondria. Comparative genomics suggested a correction to the open reading frame of YNL310c, the gene encoding Zim17 in Saccharomyces cerevisiae. The revised open reading frame codes for a classic mitochondrial targeting signal, which is processed from Zim17 in the mitochondrial matrix. Loss of Zim17 selectively diminishes import of proteins into the matrix of mitochondria, but this loss of Zim17 is partially suppressed by overexpression of the J-protein Pam18/Tim14. We propose that Zim17 functions as an example of a "fractured" J-protein, where a protein like Zim17 contributes a zinc finger domain to Type III J-proteins, in toto providing for substrate loading onto Hsp70.