Interaction with RPA Is Necessary for Rad52 Repair Center Formation and for Its Mediator Activity
Interaction with RPA Is Necessary for Rad52 Repair Center Formation and for Its Mediator Activity
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DOI：
10.1074/jbc.m804881200
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发表时间：
2008-10-24
影响因子：
4.8
通讯作者：
Mortensen, Uffe H.
中科院分区：
文献类型：
--
作者：
Plate, Iben;Hallwyl, Swee C. L.;Mortensen, Uffe H.
同源重组（HR）是一种主要的DNA修复途径，因此对维持基因组的完整性至关重要。HR由RAD 52上位组基因编码的蛋白质催化，包括重组酶Rad51及其介体Rad52。与绿色荧光蛋白融合的HR蛋白在受损DNA处形成病灶，反映了具有高浓度修复蛋白的修复中心的组装。Rad52介导Rad51和其他HR蛋白对DNA损伤的募集。为了了解Rad52依赖性DNA修复中心的组装机制，我们使用突变策略来鉴定Rad52结构域对其招募到DNA修复灶至关重要。我们目前的证据表明，在Rad52的酸性结构域在DNA修复焦点的形成。该结构域中的突变赋予显著的DNA损伤敏感性和重组缺陷。重要的是，这些Rad52突变体与单链DNA结合因子RPA的相互作用特异性受损。基于这些发现，我们提出了一个模型，Rad52取代RPA从单链DNA使用的酸性结构域作为分子杠杆。
Homologous recombination (HR) is a major DNA repair pathway and therefore essential for maintaining the integrity of the genome. HR is catalyzed by proteins encoded by genes of the RAD52 epistasis group, including the recombinase Rad51 and its mediator Rad52. HR proteins fused with green fluorescent protein form foci at damaged DNA reflecting the assembly of repair centers that harbor a high concentration of repair proteins. Rad52 mediates the recruitment of Rad51 and other HR proteins to DNA damage. To understand the mechanism for the assembly of Rad52-dependent DNA repair centers, we used a mutational strategy to identify a Rad52 domain essential for its recruitment to DNA repair foci. We present evidence to implicate an acidic domain in Rad52 in DNA repair focus formation. Mutations in this domain confer marked DNA damage sensitivity and recombination deficiency. Importantly, these Rad52 mutants are specifically compromised for interaction with the single-stranded DNA-binding factor RPA. Based on these findings, we propose a model where Rad52 displaces RPA from single-stranded DNA using the acidic domain as a molecular lever.