Chemical proteomics reveals a γH2AX-53BP1 interaction in the DNA damage response.
Chemical proteomics reveals a γH2AX-53BP1 interaction in the DNA damage response.
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DOI：
10.1038/nchembio.1908
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发表时间：
2015-10
影响因子：
14.8
通讯作者：
Kapoor TM
中科院分区：
文献类型：
--
作者：
Kleiner RE;Verma P;Molloy KR;Chait BT;Kapoor TM
DNA双链断裂修复涉及组蛋白变异体H_2AX(‘γH_2AX’)的磷酸化，它聚集在损伤部位的病灶中。在目前的模型中，多个DNA修复蛋白在γH_2AX焦点上的招募主要取决于单个蛋白MDC1对这一‘标记’的识别。然而，γ修复蛋白在没有mdc1的MDC1h2AX位点积累，这表明存在其他“读者”。在这里，我们使用定量化学蛋白质组学的方法来分析天然蛋白质组中直接的、磷酸选择性的γH2 AX结合蛋白。我们鉴定了γH_2AX结合子，包括DNA修复介体53BP1，我们发现它通过它的BRCT域识别γH_2AX。此外，我们还研究了野生型53BP1或缺乏DNAH2AX结合的突变形式对内源性和外源性γ损伤造成的染色体断裂的靶向性。我们的结果显示了DNAH2AX的直接识别如何调节γ损伤部位的蛋白质定位，并表明特定的染色质“标记”-“阅读器”相互作用如何有助于确保基因组稳定性的基本机制。
DNA double-strand break repair involves phosphorylation of histone variant H2AX (‘γH2AX’), which accumulates in foci at sites of damage. In current models, the recruitment of multiple DNA repair proteins to γH2AX foci depends mainly on recognition of this ‘mark’ by a single protein, MDC1. However, DNA repair proteins accumulate at γH2AX sites without MDC1, suggesting that other ‘readers’ exist. Here, we use a quantitative chemical proteomics approach to profile direct, phospho-selective γH2AX binders in native proteomes. We identify γH2AX binders, including the DNA repair mediator, 53BP1, which we show recognizes γH2AX through its BRCT domains. Furthermore, we investigate targeting of wild-type 53BP1 or a mutant form deficient in γH2AX binding, to chromosomal breaks resulting from endogenous and exogenous DNA damage. Our results show how direct recognition of γH2AX modulates protein localization at DNA damage sites, and suggest how specific chromatin ‘mark’-‘reader’ interactions contribute to essential mechanisms ensuring genome stability.