RNA EDITING AS A SOURCE OF GENETIC-VARIATION
RNA EDITING AS A SOURCE OF GENETIC-VARIATION
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DOI：
10.1038/363179a0
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发表时间：
1993-05-13
期刊：
影响因子：
64.8
通讯作者：
GILBERT, W
中科院分区：
文献类型：
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作者：
LANDWEBER, LF;GILBERT, W
KINETOPLASTID RNA编辑通过添加和删除尿苷残基来改变线粒体RNA转录物1，产生开放阅读框，其长度可能是原始RNA2的两倍。虽然在布鲁氏锥虫中编码细胞色素c氧化酶亚基III的COIII基因沿其整个长度进行了编辑2，但在两种相关的锥虫，利什曼绦虫和束状棘虫中可能同源的基因仅在其5'端进行了少量编辑1。我们使用比较方法来研究编辑基因的进化，并确定编辑如何很好地创造保守的蛋白质序列。由于RNA编辑可能涉及到几个引导RNA分子与信使rna3,4的配对，我们期望编辑的蛋白质能够抵抗进化变化。在这里，我们报道了RNA编辑在四种昆虫寄生虫Herpetomonas的线粒体中广泛存在，这可能是T. bruei和L. tarentolae5的进化前体，并且发现RNA编辑是进化过程中移态突变的新来源。经过编辑的蛋白质积累突变的速度几乎是未经编辑的蛋白质的两倍。
KINETOPLASTID RNA editing alters mitochondrial RNA transcripts by addition and deletion of uridine residues1, producing open reading frames that may be twice as long as the original RNA2. Although the COIII gene encoding cytochrome c oxidase subunit III in Trypanosoma brucei is edited along its entire length2, the presumably homologous genes in two related trypanosomes, Leishmania tarentolae and Crithidia fasciculata, are only modestly edited at their 5' ends1. We used a comparative approach to investigate the evolution of an edited gene and to determine how well editing creates conserved protein sequences. As RNA editing probably involves the pairing of several guide RNA molecules with the messenger RNA3,4, We expected the edited proteins to be resistant to evolutionary change. Here we report that RNA editing is extensive in the mitochondria of four species of the insect parasite Herpetomonas, which is possibly an evolutionary precursor of T. brucei and L. tarentolae5, and the discovery that RNA editing is a novel source ot frameshift mutations over evolutionary time. The edited proteins accumulate mutations nearly twice as rapidly as the unedited versions.