A genomewide screen for petite-negative yeast strains yields a new subunit of the i-AAA protease complex
A genomewide screen for petite-negative yeast strains yields a new subunit of the i-AAA protease complex
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DOI：
10.1091/mbc.e05-06-0585
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发表时间：
2006-01-01
影响因子：
3.3
通讯作者：
Jensen, RE
中科院分区：
文献类型：
--
作者：
Dunn, CD;Lee, MS;Jensen, RE
与许多其他生物不同，酿酒酵母可以容忍线粒体DNA（mtDNA）的丢失。虽然已经鉴定了一些蛋白质是酵母细胞在没有mtDNA的情况下生存所必需的，但mtDNA非依赖性生长的机制尚未完全理解。为了探索线粒体基因组和细胞活力之间的关系，我们进行了基于微阵列的全基因组筛选线粒体DNA依赖性酵母突变体。在我们发现的几个基因中，MGR 1编码位于线粒体内膜中的i-AAA蛋白酶复合物的一个新亚基。mgr 1 Delta突变体保留了一些i-AAA蛋白酶活性，但缺乏Mgr 1 p的线粒体含有错误组装的i-AAA蛋白酶，并且线粒体内膜蛋白的周转有缺陷。我们的研究结果强调了在缺乏线粒体DNA的细胞中，i-AAA复合物和内膜蛋白水解的重要性。
Unlike many other organisms, the yeast Saccharomyces cerevisiae can tolerate the loss of mitochondrial DNA (mtDNA). Although a few proteins have been identified that are required for yeast cell viability without mtDNA, the mechanism of mtDNA-independent growth is not completely understood. To probe the relationship between the mitochondrial genome and cell viability, we conducted a microarray-based, genomewide screen for mitochondrial DNA-dependent yeast mutants. Among the several genes that we discovered is MGR1, which encodes a novel subunit of the i-AAA protease complex located in the mitochondrial inner membrane. mgr1 Delta mutants retain some i-AAA protease activity, yet mitochondria lacking Mgr1p contain a misassembled i-AAA protease and are defective for turnover of mitochondrial inner membrane proteins. Our results highlight the importance of the i-AAA complex and proteolysis at the inner membrane in cells lacking mitochondrial DNA.