PARP1-dependent kinetics of recruitment of MRE11 and NBS1 proteins to multiple DNA damage sites
PARP1-dependent kinetics of recruitment of MRE11 and NBS1 proteins to multiple DNA damage sites
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DOI：
10.1074/jbc.m706734200
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发表时间：
2008-01-11
影响因子：
4.8
通讯作者：
Poirier, Guy G.
中科院分区：
文献类型：
--
作者：
Haince, Jean-Francois;McDonald, Darin;Poirier, Guy G.
聚（ADP-核糖）聚合酶1（PARP 1）是一种核酶，其被DNA链断裂快速激活，并通过将ADP-核糖单元连接到染色质相关蛋白来发出DNA损伤存在的信号。PARP抑制剂在增强电离辐射的杀伤作用中的治疗应用已被充分记录，并且作为癌症治疗吸引了越来越多的兴趣。然而，PARP 1识别多个DNA损伤的初始动力学以及PARP的抑制如何增强DNA损伤剂的活性尚不清楚。在这里，我们报告的时空动态PARP 1招聘激光微辐射诱导的DNA损伤在单个活细胞。我们提供了直接的证据表明，PARP 1能够在局部诱导的DNA双链断裂中积累。最重要的是，我们观察到MRE 11和NBS 1在DNA损伤位点的快速积累需要PARP 1。通过确定DNA损伤后蛋白质组装的动力学，我们的研究揭示了PARP 1与DNA损伤附近的双链断裂传感器MRE 11和NBS 1之间的合作。这可以解释癌细胞对PARP抑制剂的敏感性。
Poly(ADP-ribose) polymerase 1 (PARP1) is a nuclear enzyme that is rapidly activated by DNA strand breaks and signals the presence of DNA lesions by attaching ADP-ribose units to chromatin-associated proteins. The therapeutic applications of PARP inhibitors in potentiating the killing action of ionizing radiation have been well documented and are attracting increasing interest as a cancer treatment. However, the initial kinetics underlying the recognition of multiple DNA lesions by PARP1 and how inhibition of PARP potentiates the activity of DNA-damaging agents are unknown. Here we report the spatiotemporal dynamics of PARP1 recruitment to DNA damage induced by laser microirradiation in single living cells. We provide direct evidence that PARP1 is able to accumulate at a locally induced DNA double strand break. Most importantly, we observed that the rapid accumulation of MRE11 and NBS1 at sites of DNA damage requires PARP1. By determining the kinetics of protein assembly following DNA damage, our study reveals the cooperation between PARP1 and the double strand break sensors MRE11 and NBS1 in the close vicinity of a DNA lesion. This may explain the sensitivity of cancer cells to PARP inhibitors.