Stuart K, Allen T E, Heidmann S, Seiwert S D
Seattle Biomedical Research Institute, Washington 98109-1651, USA.
Microbiol Mol Biol Rev. 1997 Mar;61(1):105-20. doi: 10.1128/mmbr.61.1.105-120.1997.
Mitochondrial transcripts in kinetoplastids undergo remarkable posttranscriptional editing by uridylate insertion and deletion. The often dramatic remodeling of pre-mRNA sequences is directed by small guide RNAs (gRNAs) to produce mature mRNAs. In vitro analyses of editing have been used to determine the mechanism of editing and show that editing occurs by a series of enzyme-catalyzed steps. They also show that chimeric gRNA/mRNA molecules are not editing intermediates as proposed but are aberrant end products of editing. The complexes and molecules that catalyze editing are now being identified and characterized. The origin of editing, its developmental regulation which helps control the switching between terminal respiratory systems during the life cycle of trypanosomes, and other areas for future study are discussed.
动质体中的线粒体转录本通过尿苷酸的插入和缺失进行显著的转录后编辑。前体mRNA序列常常发生剧烈的重塑，这由小向导RNA（gRNA）引导以产生成熟的mRNA。编辑的体外分析已被用于确定编辑机制，并表明编辑是通过一系列酶催化步骤发生的。这些分析还表明，嵌合的gRNA/mRNA分子并非如所提出的那样是编辑中间体，而是编辑的异常终产物。目前正在鉴定和表征催化编辑的复合物和分子。文中还讨论了编辑的起源、其发育调控（这有助于在锥虫生命周期中控制终端呼吸系统之间的转换）以及其他未来研究领域。
