Wiesenberger G, Fox T D
Section of Genetics and Development, Cornell University, Ithaca, New York 14853-2703, USA.
Mol Cell Biol. 1997 May;17(5):2816-24. doi: 10.1128/MCB.17.5.2816.
Nuclear mutations that inactivate the Saccharomyces cerevisiae gene PET127 dramatically increased the levels of mutant COX3 and COX2 mitochondrial mRNAs that were destabilized by mutations in their 5' untranslated leaders. The stabilizing effect of pet127 delta mutations occurred both in the presence and in the absence of translation. In addition, pet127 delta mutations had pleiotropic effects on the stability and 5' end processing of some wild-type mRNAs and the 15S rRNA but produced only a leaky nonrespiratory phenotype at 37 degrees C. Overexpression of PET127 completely blocked respiratory growth and caused cells to lose wild-type mitochondrial DNA, suggesting that too much Pet127p prevents mitochondrial gene expression. Epitope-tagged Pet127p was specifically located in mitochondria and associated with membranes. These findings suggest that Pet127p plays a role in RNA surveillance and/or RNA processing and that these functions may be membrane bound in yeast mitochondria.
使酿酒酵母基因PET127失活的核突变显著增加了突变型COX3和COX2线粒体mRNA的水平，这些mRNA因其5'非翻译前导序列中的突变而不稳定。pet127δ突变的稳定作用在有翻译和无翻译的情况下均会发生。此外，pet127δ突变对一些野生型mRNA和15S rRNA的稳定性及5'末端加工具有多效性影响，但在37℃时仅产生渗漏性非呼吸表型。PET127的过表达完全阻断了呼吸生长，并导致细胞失去野生型线粒体DNA，这表明过多的Pet127p会阻止线粒体基因表达。带有表位标签的Pet127p特异性定位于线粒体并与膜相关。这些发现表明，Pet127p在RNA监测和/或RNA加工中发挥作用，并且这些功能可能在酵母线粒体中与膜结合。
