【摘要】 电离辐射诱导的DNA双链断裂(DSBs)导致组蛋白H 2 AX迅速发生磷酸化，大量磷酸化的H 2 AX(称为γ-H 2 AX)聚集在DSBs位点形成分子斑点。其他外源基因毒性剂、复制胁迫、V(D)J和CSR重组、减数分裂、功能紊乱的端粒、凋亡等也能诱导γ-H 2 AX的产生并形成分子斑点。γ-H 2 AX对信号和修复蛋白聚集并保持在DSBs位点是必不可少的，并且在DNA修复、细胞周期检查点控制、减数分裂重组、免疫球蛋白基因重排、基因组稳定的维持和肿瘤抑制中起着重要作用。许多人认为γ-H 2 AX通过调节染色质的重构使信号和修复因子聚集在DSBs位点。

    【关键词】 组蛋白H 2 AX;DNA双链断裂;DNA修复;基因组稳定性

    Phosphorylation of histone H 2 AX and its role in maintenance of genomic stabili-ty

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    XIA Jing-Guang，WANG Ju-Fang，LI Wen-Jian.Institute of Modern Physics，Chinese Academy of Sciences，Lanzhou730000，China.

    【Abstract】 Phosphorylation of H 2 AX occurs rapidly after ionizing radiation and a large number of phosphorylated H 2 AX molecules(namedγ-H 2 AX)form foci surrounding DNA DSBs.Other external genotoxic agents，replication stress，V(D)J and CSR recombination，meiotic recombination，dysfunctional telomeres，and apoptosis can also cause the formation ofγ-H 2 AX foci.Many experiments demonstrate thatγ-H 2 AX is essentially required for the accumu-lation and maintenance of signalling and repair proteins at sites of DSBs，and play an important role in DNA repair ......