两个复制叉维护途径融合了反转的重复来重新排列染色体
Lingchuan Hu1, Tae Moon Kim, Mi Young Son
1Department of Molecular Medicine/Institute of Biotechnology, The Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245-3207, USA.
Nature
|September 10, 2013
概括
缺陷的DNA修复途径可能导致染色体重排. 这项研究确定了两个不同的途径,一个由BLM调节,另一个由RAD18,这些途径融合DNA重复,导致基因组不稳定性和潜在的疾病.
科学领域:
- 遗传学 是一个遗传学.
- 分子生物学分子生物学
- 基因组不稳定性 基因组不稳定性
背景情况:
- 复制叉维护途径对于染色体完整性至关重要.
- 功能障碍的途径,特别是非基重复,可以导致癌症和基因组疾病.
- 同源重组和无错后复制修复 (EF-PRR) 是其中的关键机制.
研究的目的:
- 在小鼠胚胎干细胞中划出负责自发融合的反转重复的独特途径.
- 调查布鲁姆综合征突变 (BLM) 酶和RAD18在这些融合途径中的作用.
- 阐明TREX2外核酶在重复融合中的参与及其与EF-PRR的关系.
主要方法:
- 使用野生型老鼠胚胎干细胞.
- 用玛辐射和紫外线诱导DNA损伤.
- 分析重复的融合事件及其由BLM,RAD18和TREX2.2等特定蛋白调节.
- 评估增殖细胞核抗原 (PCNA) 无处不在和复制叉停滞.
主要成果:
- 马辐射诱导了一条由BLM调节的通路,该通路融合了相同的重复.
- 紫外线诱导了一条依赖于RAD18的途径,该途径融合了不匹配的重复.
- TREX2抑制了相同的重复融合,但增强了不匹配的重复融合,将其与EF-PRR和UBC13联系起来.
结论:
- 两个不同的途径,由BLM和RAD18分别调节,介导自发反转重复融合.
- TREX2 作为 EF-PRR 途径的一个新型组件,可以区分相同和不匹配的重复聚变.
- 复制分叉停滞被认为是两种途径重复融合的因果机制,突出显示了复制分叉维护的重要性.
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