PET111, a Saccharomyces cerevisiae nuclear gene required for translation of the mitochondrial mRNA encoding cytochrome c oxidase subunit II.
PET111, a Saccharomyces cerevisiae nuclear gene required for translation of the mitochondrial mRNA encoding cytochrome c oxidase subunit II.
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DOI：
10.1093/genetics/115.4.637
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发表时间：
1987-04
期刊：
影响因子：
3.3
通讯作者：
C. Poutré;T. Fox
中科院分区：
文献类型：
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作者：
C. Poutré;T. Fox
核基因 PET111 中的突变是隐性的，并且特异性地阻止细胞色素 c 氧化酶亚基 II (coxII)（线粒体基因的产物）的积累。然而，coxII mRNA 在 pet111 突变体中的含量约为野生型的三分之一。对于这种表型最简单的解释是 PET111 是 coxII mRNA 翻译所必需的。该 mRNA 稳态水平的降低可能是由非翻译转录物降解增加引起的次要效应。 rho-mtDNA 上携带的 pet111 线粒体抑制因子绕过了 coxII 翻译中对 PET111 的要求。三个抑制子是 coxII 结构基因和其他线粒体基因之间的融合，编码嵌合蛋白，该嵌合蛋白由与 coxII 前体蛋白融合的其他线粒体编码蛋白的 N 端部分组成。当与 rho+ mtDNA 以异质状态一起存在时，这些抑制因子允许在 pet111 突变体中合成 coxII。因此，在野生型中，PET111 产物或受其控制的某些东西可能作用于 coxII 基因近端部分编码的位点，以促进 mRNA 的翻译。 PET111 通过分子克隆分离出来，并通过基因定位到 XIII 号染色体上 rna1 和 SUP8 之间的大约中间位置。
Mutations in the nuclear gene PET111 are recessive and specifically block accumulation of cytochrome c oxidase subunit II (coxII), the product of a mitochondrial gene. However, the coxII mRNA is present in pet111 mutants at a level approximately one-third that of wild type. The simplest explanation for this phenotype is that PET111 is required for translation of the coxII mRNA. The reduced steady-state level of this mRNA is probably a secondary effect, caused by increased degradation of the untranslated transcript. Mitochondrial suppressors of pet111, carried on rho-mtDNAs, bypass the requirement for PET111 in coxII translation. Three suppressors are fusions between the coxII structural gene and other mitochondrial genes, that encode chimeric proteins consisting of the N-terminal portions of other mitochondrially coded proteins fused to the coxII precursor protein. When present together with rho+ mtDNA in a heteroplasmic state, these suppressors allow coxII synthesis in pet111 mutants. Thus in wild type, the PET111 product, or something under its control, probably acts at a site coded in the proximal portion of the gene for coxII to promote translation of the mRNA. PET111 was isolated by molecular cloning and genetically mapped to a position approximately midway between rna1 and SUP8 on chromosome XIII.