Recruitment of Bacillus subtilis RecN to DNA double-strand breaks in the absence of DNA end processing
Recruitment of Bacillus subtilis RecN to DNA double-strand breaks in the absence of DNA end processing
复制标题
DOI：
10.1128/jb.188.2.353-360.2006
复制
发表时间：
2006-01-01
影响因子：
3.2
通讯作者：
Alonso, JC
中科院分区：
文献类型：
--
作者：
Sanchez, H;Kidane, D;Alonso, JC
枯草芽孢杆菌中双链断裂（DSB）对3'单链DNA（ssDNA）突出端结构的识别和加工知之甚少。addA和addB中的突变或recJ（Delta recJ）、recQ（Delta recQ）或recS（Delta recS）基因中的无效突变，当存在于否则-Rec（+）细胞中时，使细胞对不同DNA损伤剂的杀伤作用中度敏感。在addAB细胞中RecQ样解旋酶（Delta recQ或Delta recS）的失活显示出累加效应;然而，当Delta recJ与addAB组合时，观察到强烈的协同效应，存活率与Delta recA细胞相似。RecF与RecJ或AddAB无上位性。在DSB诱导后，在addAB Delta recJ细胞中形成RecN-黄色荧光蛋白（YFP）灶。AddAB和RecJ是形成单个RecN病灶所必需的，因为在它们不存在的情况下，多个RecN-YFP病灶在细胞内积累。绿色荧光蛋白-RecA不能在addAB Delta recJ细胞中形成丝状结构（称为线）。我们提出RecN是在活细胞中响应于DSB而被检测为离散焦点的第一个重组蛋白之一，并且AddAB或RecQ（S）-RecJ是产生具有RecA的细丝形成所需的3 '-ssDNA尾的双链体所必需的。
The recognition and processing of double-strand breaks (DSBs) to a 3' single-stranded DNA (ssDNA) overhang structure in Bacillus subtilis is poorly understood. Mutations in addA and addB or null mutations in recJ (Delta recJ), recQ (Delta recQ), or recS (Delta recS) genes, when present in otherwise-Rec(+) cells, render cells moderately sensitive to the killing action of different DNA-damaging agents. Inactivation of a RecQ-like helicase (Delta recQ or Delta recS) in addAB cells showed an additive effect; however, when Delta recJ was combined with addAB, a strong synergistic effect was observed with a survival rate similar to that of Delta recA cells. RecF was nonepistatic with RecJ or AddAB After induction of DSBs, RecN-yellow fluorescent protein (YFP) foci were formed in addAB Delta recJ cells. AddAB and RecJ were required for the formation of a single RecN focus, because in their absence multiple RecN-YFP foci accumulated within the cells. Green fluorescent protein-RecA failed to form filamentous structures (termed threads) in addAB Delta recJ cells. We propose that RecN is one of the first recombination proteins detected as a discrete focus in live cells in response to DSBs and that either AddAB or RecQ(S)-RecJ are required for the generation of a duplex with a 3'-ssDNA tail needed for filament formation of RecA.