Transcript-RNA-templated DNA recombination and repair.
Transcript-RNA-templated DNA recombination and repair.
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DOI：
10.1038/nature13682
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发表时间：
2014-11-20
期刊：
影响因子：
64.8
通讯作者：
Storici F
中科院分区：
文献类型：
--
作者：
Keskin H;Shen Y;Huang F;Patel M;Yang T;Ashley K;Mazin AV;Storici F
同源重组（HR）是一个在DNA代谢中起着多种重要作用的分子过程，无论是DNA修复还是所有生命形式的遗传变异。通常，HR涉及两个相同或几乎相同的DNA分子之间的遗传信息交换;然而，HR也可以发生在RNA分子之间，如RNA病毒所示。先前的研究表明，合成的RNA寡核苷酸（oligos）可以在酵母和人类细胞中作为DNA双链断裂（DSB）修复的模板，而注入纤毛虫细胞中的人工长RNA模板可以指导基因组重排。在这里，我们报告，内源性转录RNA介导的HR与染色体DNA在酵母酿酒酵母。我们开发了一个系统来检测事件的HR启动转录RNA修复后发生的染色体DSB的同源，但远程基因座（反式），或在同一个转录产生基因座（顺式）在逆转录缺陷的酵母菌株。我们发现RNA-DNA重组被核糖核酸酶（RNase）H1和H2阻断。在RNA酶H存在的情况下，DSB修复通过cDNA中间体进行，而在它们不存在的情况下，它直接通过RNA进行。转录物与其染色体DNA伴侣的顺式接近促进了DSB修复期间Rad 52驱动的HR。在雅阁，我们证明，酵母和人类Rad 52蛋白有效地催化退火RNA的DSB样DNA末端在体外。我们的研究结果揭示了一种新的机制，HR和DNA修复的转录RNA模板。因此，考虑到细胞中大量的RNA转录物，RNA对基因组稳定性和可塑性的影响可能是巨大的。
Homologous recombination (HR) is a molecular process that plays multiple important roles in DNA metabolism, both for DNA repair and genetic variation in all forms of life. Generally, HR involves exchange of genetic information between two identical or nearly identical DNA molecules; however, HR can also occur between RNA molecules, as shown for RNA viruses. Previous research showed that synthetic RNA oligonucleotides (oligos) can template DNA double-strand break (DSB) repair in yeast and human cells, and artificial long RNA templates injected in ciliate cells can guide genomic rearrangements. Here we report that endogenous transcript RNA mediates HR with chromosomal DNA in yeast Saccharomyces cerevisiae. We developed a system to detect events of HR initiated by transcript RNA following repair of a chromosomal DSB occurring either in a homologous but remote locus (in trans), or in the same transcript-generating locus (in cis) in reverse transcription defective yeast strains. We found that RNA-DNA recombination is blocked by ribonucleases (RNases) H1 and H2. In the presence of RNases H, DSB repair proceeds through a cDNA intermediate, whereas in their absence, it proceeds directly through RNA. The proximity of the transcript to its chromosomal DNA partner in cis facilitates Rad52-driven HR during DSB repair. In accord, we demonstrate that yeast and human Rad52 proteins efficiently catalyze annealing of RNA to a DSB-like DNA end in vitro. Our results reveal a novel mechanism of HR and DNA repair templated by transcript RNA. Thus, considering the abundance of RNA transcripts in cells, the impact of RNA on genomic stability and plasticity could be vast.