在Saccharomyces cerevisiae中的DNA双链断裂部位的染色体重塑
Toyoko Tsukuda1, Alastair B Fleming, Jac A Nickoloff
1Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud Albuquerque, New Mexico 87131, USA.
Nature
|November 18, 2005
概括
双链DNA断裂引发了基因组修饰和核细胞体损失,这对基因组稳定至关重要. MRX复合体和INO80重塑器协调这些染色质变化,促进DNA修复蛋白的招募.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 细胞生物学 细胞生物学
背景情况:
- DNA双链断裂 (DSBs) 威胁着基因组的稳定性,并通过非同源端连接和同源重组来修复.
- 在DSB之后的染色质变化对于有效的修复至关重要,涉及像H2A.X酸化这样的基因组修饰.
研究的目的:
- 为了研究Saccharomyces cerevisiae中DSB附近的染色质结构变化.
- 阐明特定蛋白质复合体在调解这些染色质变化的作用及其对DNA修复的影响.
主要方法:
- 通过微球菌核酶消化对基因组修饰 (H2A酸化) 和核细胞损失的分析.
- 调查DNA损伤传感器MRX和核细胞重塑复合体INO80对基因素损失的需求.
- 评估修复蛋白Rad51.1.的招募动态
主要成果:
- DSB的形成会诱导H2A的酸化,然后是H2B和H3的损失,从而增加染色质的可访问性.
- 歇斯顿损失和H2A酸化是独立发生的,需要MRX复合体和INO80.0.
- 缺少组蛋白损失延迟了Rad51的招募,这表明MRX介导的核细胞体重塑调节了同源重组因子的获取.
结论:
- 该MRX复合体协调了不同的染色质修饰途径:核细胞位移用于同源重组蛋白招募和H2A酸化用于检查点信号.
- 依赖MRX的核细胞重塑对于修复因子有效地进入DSB至关重要,这突出了同源重组的关键监管步骤.
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