Dellaire Graham, Bazett-Jones David P
Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada.
Cell Cycle. 2007 Aug 1;6(15):1864-72. doi: 10.4161/cc.6.15.4560. Epub 2007 Jun 11.
In the mid to late 1990s several groups identified DNA damage-dependent focal accumulations in nuclei of both DNA repair factors and the phosphorylated form of the histone variant H2A.X. The term "repair foci" has since been used to describe these protein accumulations. As a molecular marker for DNA damage, they have been immensely useful in the study of signal transduction pathways triggered by DNA damage while aiding in the identification of new factors involved in DNA repair. In spite of their importance, many other changes in the nuclear landscape correlate with DNA damage and repair processes. These include dramatic changes in chromatin ultrastructure and epigenetic modifications, which occur at the site of DNA breaks as well as globally throughout the nucleus. Besides chromatin, DNA damage also affects the dynamic behaviour, morphology and biochemical composition of various subnuclear domains, including the nucleolus, promyelocytic leukemia (PML) nuclear bodies and Cajal bodies. These changes in the nuclear landscape, the topic of this review, appear to be intimately linked to the cellular response to DNA damage and may prove as useful as repair foci in elucidating mechanisms of DNA repair.
在20世纪90年代中后期,几个研究小组在DNA修复因子和组蛋白变体H2A.X的磷酸化形式的细胞核中发现了依赖DNA损伤的局灶性聚集。从那时起,“修复灶”一词就被用来描述这些蛋白质聚集。作为DNA损伤的分子标记,它们在研究由DNA损伤触发的信号转导途径以及帮助鉴定参与DNA修复的新因子方面非常有用。尽管它们很重要,但核内环境中的许多其他变化与DNA损伤和修复过程相关。这些变化包括染色质超微结构和表观遗传修饰的显著改变,这些改变发生在DNA断裂位点以及整个细胞核中。除了染色质,DNA损伤还影响各种核内亚结构域的动态行为、形态和生化组成,包括核仁、早幼粒细胞白血病(PML)核体和卡哈尔体。核内环境的这些变化是本综述的主题,似乎与细胞对DNA损伤的反应密切相关,并且在阐明DNA修复机制方面可能与修复灶一样有用。