McMullin T W, Haffter P, Fox T D
Section of Genetics and Development, Cornell University, Ithaca, New York 14853-2703.
Mol Cell Biol. 1990 Sep;10(9):4590-5. doi: 10.1128/mcb.10.9.4590-4595.1990.
Mitochondrial translation of the mRNA encoding cytochrome c oxidase subunit III (coxIII) specifically requires the action of three position activator proteins encoded in the nucleus of Saccharomyces cerevisiae. Some mutations affecting one of these activators, PET122, can be suppressed by mutations in an unlinked nuclear gene termed PET123. PET123 function was previously demonstrated to be required for translation of all mitochondrial gene products. We have now generated an antibody against the PET123 protein and have used it to demonstrate that PET123 is a mitochondrial ribosomal protein of the small subunit. PET123 appears to be present at levels comparable to those of other mitochondrial ribosomal proteins, and its accumulation is dependent on the presence of the 15S rRNA gene in mitochondria. Taken together with the previous genetic data, these results strongly support a model in which the mRNA-specific translational activator PET122 works by directly interacting with the small ribosomal subunit to promote translation initiation on the coxIII mRNA.
编码细胞色素c氧化酶亚基III（coxIII）的mRNA的线粒体翻译特别需要酿酒酵母细胞核中编码的三种位置激活蛋白的作用。一些影响其中一种激活蛋白PET122的突变可以被一个名为PET123的非连锁核基因中的突变所抑制。先前已证明PET123功能是所有线粒体基因产物翻译所必需的。我们现在已经产生了一种针对PET123蛋白的抗体，并使用它来证明PET123是小亚基的线粒体核糖体蛋白。PET123的含量似乎与其他线粒体核糖体蛋白相当，并且其积累依赖于线粒体中15S rRNA基因的存在。结合先前的遗传数据，这些结果有力地支持了一个模型，即mRNA特异性翻译激活因子PET122通过直接与小核糖体亚基相互作用来促进coxIII mRNA上的翻译起始。
