Wegierski T, Dmochowska A, Jabłonowska A, Dziembowski A, Bartnik E, Stepień P P
Department of Genetics, University of Warsaw, Poland.
Acta Biochim Pol. 1998;45(4):935-40.
Saccharomyces cerevisiae nuclear genes SUV3 and DSS1 encode putative RNA helicase and RNase II, respectively, which are subunits of the mitochondrial degradosome (mtEXO): a three-protein complex which has a 3' to 5' exoribonuclease activity and plays a major role in regulating stability of mitochondrial RNA. Lack of either of the two gene products results in a respiratory negative phenotype, while on the molecular level it causes a total block of mitochondrial translation, loss of the in vitro exoribonuclease activity and changes in stability and processing of many mtRNAs. We have found that the yeast nuclear gene PET127 present on a low or high copy number vector can effectively suppress the effects of the SUV3 or DSS1 gene disruptions. Since the product of the PET127 gene is involved in processing of the 5' ends of mitochondrial mRNAs, we suggest that there is a functional coupling between the 5' and 3' ends of mitochondrial mRNAs.
酿酒酵母的核基因SUV3和DSS1分别编码假定的RNA解旋酶和核糖核酸酶II，它们是线粒体降解体（mtEXO）的亚基：一种具有3'到5'外切核糖核酸酶活性的三蛋白复合物，在调节线粒体RNA稳定性方面起主要作用。缺少这两种基因产物中的任何一种都会导致呼吸阴性表型，而在分子水平上，它会导致线粒体翻译完全受阻、体外外切核糖核酸酶活性丧失以及许多线粒体RNA的稳定性和加工过程发生变化。我们发现，存在于低拷贝或高拷贝载体上的酵母核基因PET127可以有效抑制SUV3或DSS1基因破坏的影响。由于PET127基因的产物参与线粒体mRNA 5'端的加工，我们认为线粒体mRNA的5'端和3'端之间存在功能耦合。
