Departamento de Genética, Universidad de Sevilla, 41080 Sevilla, Spain.
Department of Regenerative Medicine, Centro Andaluz de Biología Molecular y Medicina Regenerativa, 41092 Sevilla, Spain.
Nat Commun. 2016 Aug 9;7:12364. doi: 10.1038/ncomms12364.
There are two major and alternative pathways to repair DNA double-strand breaks: non-homologous end-joining and homologous recombination. Here we identify and characterize novel factors involved in choosing between these pathways; in this study we took advantage of the SeeSaw Reporter, in which the repair of double-strand breaks by homology-independent or -dependent mechanisms is distinguished by the accumulation of green or red fluorescence, respectively. Using a genome-wide human esiRNA (endoribonuclease-prepared siRNA) library, we isolate genes that control the recombination/end-joining ratio. Here we report that two distinct sets of genes are involved in the control of the balance between NHEJ and HR: those that are required to facilitate recombination and those that favour NHEJ. This last category includes CCAR2/DBC1, which we show inhibits recombination by limiting the initiation and the extent of DNA end resection, thereby acting as an antagonist of CtIP.
有两种主要的替代途径来修复 DNA 双链断裂：非同源末端连接和同源重组。在这里，我们鉴定并描述了参与选择这些途径的新的因素；在这项研究中，我们利用了 SeeSaw Reporter，通过该报告器，可以通过同源非依赖性或依赖性机制修复双链断裂，分别积累绿色或红色荧光。使用全基因组人类 esiRNA（内切酶制备的 siRNA）文库，我们分离出控制重组/末端连接比的基因。在这里，我们报告了两组不同的基因参与控制 NHEJ 和 HR 之间的平衡：那些有助于促进重组的基因和那些有利于 NHEJ 的基因。最后这一类包括 CCAR2/DBC1，我们发现它通过限制 DNA 末端切除的起始和程度来抑制重组，从而作为 CtIP 的拮抗剂。
