Rpm2, the protein subunit of mitochondrial RNase P in Saccharomyces cerevisiae, also has a role in the translation of mitochondrially encoded subunits of cytochrome c oxidase.
Rpm2, the protein subunit of mitochondrial RNase P in Saccharomyces cerevisiae, also has a role in the translation of mitochondrially encoded subunits of cytochrome c oxidase.
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Rpm2 是酿酒酵母中线粒体 RNase P 的蛋白质亚基，也在线粒体编码的细胞色素 C 氧化酶亚基的翻译中发挥作用。
DOI：
10.1093/genetics/158.2.573
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发表时间：
2001
期刊：
影响因子：
3.3
通讯作者：
Martin,NC
中科院分区：
文献类型：
--
作者：
Stribinskis,V;Gao,GJ;Ellis,SR;Martin,NC
RPM2是一个酿酒酵母核基因，编码线粒体RNase P的蛋白亚基，对发酵生长具有未知的功能。缺乏线粒体RNase P的细胞不能呼吸并在线粒体DNA中积累损伤。一个新的RPM2等位基因rpm2-100的作用揭示了RPM2在线粒体生物发生中的新功能。以rpm2-100为Rpm2p唯一来源的细胞已正确处理线粒体tRNA，但仍有呼吸缺陷。与野生型相比，rpm2-100细胞线粒体mRNA和rRNA水平降低。MRNA的普遍减少并不反映在线粒体蛋白质合成的类似减少上。与野生型相比，突变体标记的前体对线粒体编码的Atp6、ATP8、Atp9和Cytb蛋白的掺入增加，而对Cox1p、Cox2p、Cox3p和Var1p的掺入减少。线粒体翻译的脉冲追逐分析显示COX1、COX2和COX3mRNAs的翻译速率降低。这种下降导致Cox1p、Cox2p和Cox3p的稳态水平较低，aa3细胞色素的可见光谱丢失，以及突变线粒体中细胞色素c氧化酶的活性降低。因此，RPM2除了作为线粒体RNase P的一个亚单位外，在线粒体的生物发生中还具有以前未被认识的作用。此外，这一新的呼吸功能的破坏与野生型mtDNA的丢失之间存在着一种合成的致命性相互作用。这种人工合成的相互作用解释了为什么完全删除RPM2是致命的。
RPM2is aSaccharomyces cerevisiaenuclear gene that encodes the protein subunit of mitochondrial RNase P and has an unknown function essential for fermentative growth. Cells lacking mitochondrial RNase P cannot respire and accumulate lesions in their mitochondrial DNA. The effects of a newRPM2allele,rpm2-100, reveal a novel function ofRPM2in mitochondrial biogenesis. Cells withrpm2-100as their only source of Rpm2p have correctly processed mitochondrial tRNAs but are still respiratory deficient. Mitochondrial mRNA and rRNA levels are reduced inrpm2-100cells compared to wild type. The general reduction in mRNA is not reflected in a similar reduction in mitochondrial protein synthesis. Incorporation of labeled precursors into mitochondrially encoded Atp6, Atp8, Atp9, and Cytb protein was enhanced in the mutant relative to wild type, while incorporation into Cox1p, Cox2p, Cox3p, and Var1p was reduced. Pulse-chase analysis of mitochondrial translation revealed decreased rates of translation of COX1, COX2, and COX3 mRNAs. This decrease leads to low steady-state levels of Cox1p, Cox2p, and Cox3p, loss of visible spectra of aa3cytochromes, and low cytochrome c oxidase activity in mutant mitochondria. Thus,RPM2has a previously unrecognized role in mitochondrial biogenesis, in addition to its role as a subunit of mitochondrial RNase P. Moreover, there is a synthetic lethal interaction between the disruption of this novel respiratory function and the loss of wild-type mtDNA. This synthetic interaction explains why a complete deletion ofRPM2is lethal.