Chromatin dynamics mediated by histone modifiers and histone chaperones in postreplicative recombination
Chromatin dynamics mediated by histone modifiers and histone chaperones in postreplicative recombination
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DOI：
10.1111/j.1365-2443.2010.01435.x
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发表时间：
2010-09-01
期刊：
影响因子：
2.1
通讯作者：
Horikoshi, Masami
中科院分区：
文献类型：
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作者：
Endo, Hirohito;Kawashima, Satoshi;Horikoshi, Masami
真核染色质受组蛋白修饰酶、染色质重塑复合体和组蛋白伴侣等染色质因子调控，参与多种dna依赖反应。在这些反应中，染色质背景下的转录得到了很好的研究。另一方面，其他dna依赖的反应，包括复制后同源重组，如何在染色质背景下被调节仍然是难以捉摸的。在这里，由组蛋白乙酰转移酶Rtt109和组蛋白伴侣Cia1/Asf1介导的组蛋白H3 Lys56乙酰化被证明是复制后姐妹染色单体重组所必需的。这种重组没有发生在cia1/asf1-V94R突变体中，该突变体缺乏组蛋白结合和组蛋白伴侣活性，不能促进Rtt109的组蛋白乙酰转移酶活性。另一组蛋白伴侣CAF-1的缺陷导致乙酰化H3-K56 （H3-K56- ac）依赖性增殖后重组的增加。据报道，泛素连接酶复合物Rtt101-Mms1-Mms22在H3-K56-Ac信号通路的下游起作用，它识别的一些DNA损伤似乎在ca -1缺陷细胞中增加。综上所述，这些数据为组蛋白修饰因子和组蛋白伴侣以多种方式控制的复制后重组机制提供了框架。
Eukaryotic chromatin is regulated by chromatin factors such as histone modification enzymes, chromatin remodeling complexes and histone chaperones in a variety of DNA-dependent reactions. Among these reactions, transcription in the chromatin context is well studied. On the other hand, how other DNA-dependent reactions, including postreplicative homologous recombination, are regulated in the chromatin context remains elusive. Here, histone H3 Lys56 acetylation, mediated by the histone acetyltransferase Rtt109 and the histone chaperone Cia1/Asf1, is shown to be required for postreplicative sister chromatid recombination. This recombination did not occur in the cia1/asf1-V94R mutant, which lacks histone binding and histone chaperone activities and which cannot promote the histone acetyltransferase activity of Rtt109. A defect in another histone chaperone, CAF-1, led to an increase in acetylated H3-K56 (H3-K56-Ac)-dependent postreplicative recombination. Some DNA lesions recognized by the putative ubiquitin ligase complex Rtt101-Mms1-Mms22, which is reported to act downstream of the H3-K56-Ac signaling pathway, seem to be increased in CAF-1 defective cells. Taken together, these data provide the framework for a postreplicative recombination mechanism controlled by histone modifiers and histone chaperones in multiple ways.