Specific recruitment of human cohesin to laser-induced DNA damage
Specific recruitment of human cohesin to laser-induced DNA damage
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DOI：
10.1074/jbc.m209123200
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发表时间：
2002-11-22
影响因子：
4.8
通讯作者：
Yokomori, K
中科院分区：
文献类型：
--
作者：
Kim, JS;Krasieva, TB;Yokomori, K
凝聚素是一种保守的多蛋白复合物，在姐妹染色单体凝聚中起着重要作用。在分裂间期，DNA复制后的凝聚力的建立需要cohesin。由于粘附素突变体导致对DNA损伤的敏感性增加，因此也提出了粘附素在DNA修复中的作用。然而，目前还不清楚这是否是由于一般扰动的凝聚力或凝聚素是否有一个专门的作用，在损伤部位。因此，我们使用激光微束在细胞核中的离散位点产生DNA损伤，并通过免疫荧光检测观察到这些位点的蛋白质的特异性体内组装。我们观察到，人的cohesin在损伤诱导后立即被募集到损伤部位。对突变细胞的分析表明，粘附素募集到损伤部位依赖于DNA双链断裂修复因子Mre 11/Rad 50，而不是ATM或Nbs 1。一致的是，Mre 11/Rad 50和cohesin以间期特异性方式相互作用。这种相互作用在S/G（2）期达到峰值，在此期间，粘附素被募集到DNA损伤中。我们的研究结果表明，S/G（2）特异性和Mre 11/Rad 50依赖性募集的人cohesin的DNA损伤，表明细胞周期特异性DNA双链断裂修复的专门的子功能的cohesin。
Cohesin is a conserved multiprotein complex that plays an essential role in sister chromatid cohesion. During interphase, cohesin is required for the establishment of cohesion following DNA replication. Because cohesin mutants resulted in increased sensitivity to DNA damage, a role for cohesin in DNA repair was also suggested. However, it was unclear whether this was due to general perturbation of cohesion or whether cohesin has a specialized role at the damage site. We therefore used a laser microbeam to create DNA damage at discrete sites in the cell nucleus and observed specific in vivo assembly of proteins at these sites by immunofluorescent detection. We observed that human cohesin is recruited to the damage site immediately after damage induction. Analysis of mutant cells revealed that cohesin recruitment to the damage site is dependent on the DNA double-strand break repair factor Mre11/Rad50 but not ATM or Nbs1. Consistently, Mre11/Rad50 and cohesin interact with each other in an interphase-specific manner. This interaction peaks in S/G(2) phase, during which cohesin is recruited to the DNA damage. Our results demonstrate the S/G(2)-specific and Mre11/Rad50-dependent recruitment of human cohesin to DNA damage, suggesting a specialized subfunction for cohesin in cell cycle-specific DNA double strand break repair.