BRCA2 阻止了 R 循环积累,并与 TREX-2 mRNA 出口因子 PCID2 相关联
Vaibhav Bhatia1, Sonia I Barroso1, María L García-Rubio1
1Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla, Avenida Américo Vespucio s/n, 41092 Seville, Spain.
Nature
|June 5, 2014
概括
与衰老和癌症相关的基因组不稳定性,可以来自称为R-循环的RNA-DNA混合体. TREX-2复合物防止这种不稳定性,而BRCA2处理R环,突出了它们在癌症相关基因组不稳定性中的作用.
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:
- 基因组不稳定是导致衰老,癌症和疾病的关键因素.
- 预mRNA拼接和信使核糖核蛋白 (mRNP) 生物生成/出口的基因突变会导致DNA损伤和基因组不稳定.
- 通过DNA-RNA混合体形成的R环结构经常调解这种不稳定性.
研究的目的:
- 研究人类TREX-2复合体在维持基因组完整性的作用.
- 探索TREX-2,R环和基因组不稳定性之间的关系.
- 确定BRCA2在R循环处理中的参与及其与基因组稳定性的联系.
主要方法:
- 消耗TREX-2子单元 (PCID2,GANP,DSS1) 和评估基因组不稳定性标记物 (γ-H2AX,53BP1焦点,单细胞电泳).
- 同免疫沉研究BRCA2,DSS1和PCID2.2之间的关联.
- 使用增强的绿色光蛋白标记RNase H1和TREX-2和BRCA2-贫乏细胞中的S9.6抗体的混合结合域检测R环.
主要成果:
- 在TREX-2子单元PCID2,GANP和DSS1的耗尽导致基因组不稳定.
- BRCA2与PCID2相互作用,并且对于R循环处理是必需的,因为R循环积聚在BRCA2贫乏的细胞中.
- 在缺乏TREX-2的细胞中没有检测到R环,这表明TREX-2的作用是防止它们的形成或促进它们的分解.
结论:
- 在预防基因组不稳定方面,TREX-2复合体起着至关重要的作用.
- 在细胞中普遍存在的R循环中,BRCA2对于处理R循环至关重要.
- R环是复制压力的重要来源,可能导致与癌症相关的基因组不稳定性.
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