在RAD51依赖的DNA跨链交叉连接修复的机制
David T Long1, Markus Räschle, Vladimir Joukov
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
Science (New York, N.Y.)
|July 2, 2011
概括
在S阶段使用同源重组来修复DNA链间交叉链 (ICL). 在双链断裂形成之前,RAD51结合了停滞不前的复制分叉,将Fanconi贫血路径与重组联系起来.
科学领域:
- 分子生物学分子生物学
- 修复DNA修复DNA的修复
- 细胞循环规则 细胞循环规则
背景情况:
- 基因组链间交叉链 (ICL) 对基因组稳定性构成重大威胁.
- 在S阶段有效修复ICL对于真核细胞生存至关重要.
- 连接ICL传感到修复通路激活的精确机制仍然不完全理解.
研究的目的:
- 在S阶段阐明ICL修复的机制.
- 调查同源重组在修复ICL诱导的DNA双链断裂 (DSBs) 中的作用.
- 确定Fanconi贫血 (FA) 途径和RAD51介导的重组之间的功能关系.
主要方法:
- 使用Xenopus蛋提取物在体外研究ICL修复.
- 研究了在ICL处理中复制分叉融合,双切口和DSB形成的作用.
- 对相对于FANCI-FANCD2和DSB形成的RAD51结合动态进行了研究.
- 通过同源重组来评估DSB的修复.
主要成果:
- ICL修复由融合的复制叉启动,导致双切口和一个姐妹染色体中的DSB.
- 破碎的姐妹染色体通过RAD51-依赖的链入侵完整的姐妹染色体来修复.
- RAD51与ICL停滞的复制分叉结合,独立于FANCI-FANCD2和DSB形成之前.
- 在实验室中通过同源重组证明了DSB的完全修复.
结论:
- 在ICL修复中建立了Fanconi贫血路径和同类重组机制之间的功能联系.
- 展示了RAD51的早期招募到ICL停滞的分叉,在DSB形成之前.
- 通过同源重组提供了体外证据,证明DSBs通过同源重组得到完全修复,并提供了对ICL耐受性和修复策略的见解.
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