Recruitment of DNA damage checkpoint proteins to damage in transcribed and nontranscribed sequences
Recruitment of DNA damage checkpoint proteins to damage in transcribed and nontranscribed sequences
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DOI：
10.1128/mcb.26.1.39-49.2006
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发表时间：
2006-01-01
影响因子：
5.3
通讯作者：
Sancar, A
中科院分区：
文献类型：
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作者：
Jiang, GC;Sancar, A
我们开发了一种染色质免疫沉淀方法，用于分析修复蛋白和检查点蛋白与人类基因组任何区域DNA碱基病变的结合。在细胞周期的G(1)期和S期，我们研究了DNA损伤检查点蛋白RPA、Rad9和ATR在野生型和切除修复缺陷的人细胞的转录区和非转录区对紫外线和乙酰氧基乙酰氨基芴诱导的碱基损伤的募集。我们发现，在没有DNA复制或修复的情况下，测试的所有3个损伤传感器都在损伤位点或损伤附近组装，并且转录增强了检查点蛋白在损伤位点的招募。此外，我们发现紫外线照射切除修复缺陷的人类细胞会导致细胞周期G(1)期和S期Chk1激酶的磷酸化，这表明原发性DNA损伤以及停滞的转录复合物可能作为启动DNA损伤检查点反应的信号。
We developed a chromatin immunoprecipitation method for analyzing the binding of repair and checkpoint proteins to DNA base lesions in any region of the human genome. Using this method, we investigated the recruitment of DNA damage checkpoint proteins RPA, Rad9, and ATR to base damage induced by UV and acetoxyacetylaminofluorene in transcribed and nontranscribed regions in wild-type and excision repair-deficient human cells in G(1) and S phases of the cell cycle. We find that all 3 damage sensors tested assemble at the site or in the vicinity of damage in the absence of DNA replication or repair and that transcription enhances recruitment of checkpoint proteins to the damage site. Furthermore, we find that UV irradiation of human cells defective in excision repair leads to phosphorylation of Chk1 kinase in both G(1) and S phase of the cell cycle, suggesting that primary DNA lesions as well as stalled transcription complexes may act as signals to initiate the DNA damage checkpoint response.