Independent and sequential recruitment of NHEJ and HR factors to DNA damage sites in mammalian cells.
Independent and sequential recruitment of NHEJ and HR factors to DNA damage sites in mammalian cells.
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DOI：
10.1083/jcb.200411083
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发表时间：
2005-08-01
影响因子：
7.8
通讯作者：
Yokomori, Kyoko
中科院分区：
文献类型：
--
作者：
Kim, Jong-Soo;Krasieva, Tatiana B;Kurumizaka, Hitoshi;Chen, David J;Taylor, A Malcolm R;Yokomori, Kyoko
通过修复/检查点因子进行损伤识别是DNA损伤反应的关键第一步。DNA双链断裂(DSB)激活检查点信号，并通过非同源末端连接(NHEJ)和同源重组(HR)途径修复。然而，个体因子反应的体内动力学和途径选择的机制还不是很清楚。我们报告了细胞周期和时间过程的分析，共济失调-毛细血管扩张突变的检查点激活和修复因子的损伤部位招募响应激光诱导的双链断裂。我们发现MRN作为DNA损伤标志物，持续定位于未修复的损伤部位。NHEJ因素的损伤识别先于HR因素。HR因子招募不受NHEJ因子组装的影响，并贯穿于整个间期。NHEJ因子在损伤部位的滞留是暂时的，而HR因子在未修复的损伤处持续存在，揭示了这两条通路在哺乳动物细胞中的独特作用。
Damage recognition by repair/checkpoint factors is the critical first step of the DNA damage response. DNA double strand breaks (DSBs) activate checkpoint signaling and are repaired by nonhomologous end-joining (NHEJ) and homologous recombination (HR) pathways. However, in vivo kinetics of the individual factor responses and the mechanism of pathway choice are not well understood. We report cell cycle and time course analyses of checkpoint activation by ataxia-telangiectasia mutated and damage site recruitment of the repair factors in response to laser-induced DSBs. We found that MRN acts as a DNA damage marker, continuously localizing at unrepaired damage sites. Damage recognition by NHEJ factors precedes that of HR factors. HR factor recruitment is not influenced by NHEJ factor assembly and occurs throughout interphase. Damage site retention of NHEJ factors is transient, whereas HR factors persist at unrepaired lesions, revealing unique roles of the two pathways in mammalian cells.