突破诱导的复制编排了切割依赖的模板切换
Tianpeng Zhang1, Yashpal Rawal2, Haoyang Jiang1
1Department of Cancer Biology, Penn Center for Genome Integrity, Basser Center for BRCA, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Nature
|June 14, 2023
概括
破裂诱导的端粒合成 (BITS) 使用最小的复制体进行DNA修复. 在此过程中,SNM1A核酶指导无处不在的PCNA促进切除和病变绕道.
科学领域:
- 分子生物学
- DNA 修复
- 端粒生物学
背景情况:
- 断裂诱导的端粒合成 (BITS) 是一个RAD51独立的途径,对替代端粒延长至关重要.
- BITS涉及最小的复制体,包括增殖细胞核抗原 (PCNA) 和DNA聚合酶-δ,用于广泛的DNA修复合成.
- BITS对复制应激和二次DNA结构的反应尚不清楚.
研究的目的:
- 在复制压力下的BITS中调查DNA损伤反应.
- 确定在长途同源重组修复过程中参与维护过程性的关键蛋白质.
- 阐明BITS耐受复杂DNA结构的机制.
主要方法:
- 双链断裂的同步诱导
- 孤立染色体段 (PICh) 的蛋白质组学,以分析端粒DNA损伤反应蛋白质组.
- 对依赖RAD18的PCNA无化和SNM1A核酶活性进行分析.
主要成果:
- BITS引发了一种复制应激反应,其特征是依赖RAD18的PCNA无处不在.
- 该SNM1A核酶被确定为无处不在的PCNA依赖DNA损伤耐受性的关键效应因子.
- 在破裂诱导的复制体中,SNM1A识别了无处不在的PCNA,指导其核酶活性以促进切除.
结论:
- 突破诱导的复制策划了切除依赖的病变绕道.
- 在哺乳动物细胞中,SNM1A核酶活性对无处不在的PCNA导向重组至关重要.
- 这项研究揭示了BITS中DNA损伤耐受性的新机制.
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