Koslowsky D J, Riley G R, Feagin J E, Stuart K
Seattle Biomedical Research Institute, Washington 98109.
Mol Cell Biol. 1992 May;12(5):2043-9. doi: 10.1128/mcb.12.5.2043-2049.1992.
RNA editing of several mitochondrial transcripts in Trypanosoma brucei is developmentally regulated. The cytochrome b and cytochrome oxidase II mRNAs are edited in procyclic-form parasites but are primarily unedited in bloodstream forms. The latter forms lack the mitochondrial respiratory system present in procyclic forms. Editing of the NADH dehydrogenase 7 (ND7) and ND8 transcripts is also developmentally regulated but occurs preferentially in bloodstream forms. Other transcripts, cytochrome oxidase III and ATPase 6, are edited in both life forms. We have identified many minicircle-encoded guide RNAs (gRNAs) for ATPase 6, ND7, and ND8. The characteristics of these gRNAs reveal how extensively edited RNA can be edited in the 3'-to-5' direction. Northern (RNA) blot and primer extension analyses indicate that gRNAs for transcripts whose editing is developmentally regulated are present in both procyclic and bloodstream form parasites. These results suggest that the developmental regulation of editing in these transcripts is not controlled by the presence or absence of gRNAs.
布氏锥虫中几种线粒体转录本的RNA编辑受发育调控。细胞色素b和细胞色素氧化酶II的mRNA在前循环型寄生虫中被编辑，但在血流型中主要未被编辑。后者缺乏前循环型中存在的线粒体呼吸系统。NADH脱氢酶7（ND7）和ND8转录本的编辑也受发育调控，但优先发生在血流型中。其他转录本，细胞色素氧化酶III和ATP酶6，在两种生活型中都被编辑。我们已经鉴定出许多用于ATP酶6、ND7和ND8的微小环编码引导RNA（gRNA）。这些gRNA的特征揭示了经过编辑的RNA在3'到5'方向上能被编辑的程度。Northern（RNA）印迹和引物延伸分析表明，其编辑受发育调控的转录本的gRNA在前循环型和血流型寄生虫中都存在。这些结果表明，这些转录本编辑的发育调控不受gRNA的有无控制。
