ATR保护复制分叉免受APOBEC3B诱导的有毒PARP1陷
Pedro Ortega1,2,3, Elodie Bournique1,2,3, Junyi Li1,2,3
1Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA.
bioRxiv : the preprint server for biology
|November 28, 2024
概括
由于ATR抑制导致DNA不受保护,导致复制灾难. APOBEC3B酶向这种DNA,导致叉崩和PARP1过活化,解释了对ATR和PARP抑制剂的敏感性.
科学领域:
- 遗传学 是一个遗传学.
- 分子生物学分子生物学
- 癌症生物学 癌症生物学
背景情况:
- 在DNA复制过程中,ATR对于保持基因组完整性至关重要.
- 由于未受保护的单链DNA (ssDNA),ATR抑制 (ATRi) 会导致复制灾难.
- ssDNA破裂和随后的细胞事件的确切机制尚不清楚.
研究的目的:
- 为了阐明复制灾难期间DNA破裂的机制.
- 为了确定负责向未受保护的ssDNA的酶.
- 为了解释ATR抑制剂和PARP抑制剂之间观察到的合成致死性.
主要方法:
- 研究了APOBEC3B在ATR抑制剂诱导的DNA损伤中的作用.
- 利用生物化学分析来研究 uracil 切除和底层部位裂变.
- 评估了对DNA损伤的反应中PARP1的捕获和过度激活.
- 检查了细胞对ATRi和PARP抑制剂组合的敏感性.
主要成果:
- APOBEC3B将不受保护的ssDNA向复制叉,从而启动叉崩和PARP1过度激活.
- UNG2和APE1内核酶介导APOBEC3B产生的 uracils和基底位点的裂变.
- 通过APE1介导的DNA裂变对于PARP1的捕获至关重要,无论基底位置的起源如何.
- 由APOBEC3B诱导的PARP1捕获有助于细胞对ATRi的敏感性,通过PARP抑制剂产生合成致死性.
结论:
- 在ATR抑制过程中,APOBEC3B是驱动复制分叉断裂的关键酶.
- 这项研究阐明了复制灾难和PARP1过度激活的机制.
- 这些发现解释了ATRi和PARP抑制剂之间的合成致死性,提供了治疗见解.
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