通过去除压制性多ADP-ribose标记,PARG对于Polθ介导的DNA末端连接至关重要
Umeshkumar Vekariya1, Leonid Minakhin2, Gurushankar Chandramouly2
1Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.
Nature communications
|July 10, 2024
概括
聚ADP-ribose) 聚合酶1 (PARP1) 和聚ADP-ribose) 糖酶 (PARG) 调节了DNA的修复. 在DNA损伤部位,PARP1使DNA聚合酶甲基 (Polθ) 失活,而PARG则使Polθ重新激活,以进行高效的修复.
科学领域:
- 分子生物学分子生物学
- DNA 修复机制的修复机制
- 生物化学 生物化学
背景情况:
- DNA聚合酶甲基 (Polθ) 介导的末端结合 (TMEJ) 对于修复DNA双链断裂和赋予对基因毒剂的耐药性至关重要.
- 在TMEJ中,Polθ的精确分子调节仍然在很大程度上没有特征,这阻碍了对其功能的全面理解.
研究的目的:
- 阐明在TMEJ期间调节DNA聚合酶甲基 (Polθ) 的分子机制.
- 研究PARP1和PARG在调节Polθ活动和TMEJ通路功能的作用.
主要方法:
- 研究了Polθ和PARP1之间的相互作用,重点关注PARylation状态及其对Polθ活性的影响.
- 利用生物化学测试来评估修改后的Polθ.的DNA结合和末端连接活动.
- 研究了PARP1和PARG对DNA损伤部位的时空招募,并将其与TMEJ激活相关联.
主要成果:
- 确定了一种新型相互作用,其中PARP1以HPF1独立的方式PARylates Polθ,导致Polθ招募到DNA损伤部位.
- 证明PARP1的PARylation使Polθ的DNA结合和TMEJ活动失活.
- 表明PARG介导的de-PARylation重新激活Polθ,恢复其DNA结合和末端连接能力,对TMEJ至关重要.
结论:
- 建立了涉及PARP1和PARG的TMEJ两步空间时间监管机制.
- PARP1充当初始调节者,通过PARylation在DNA损伤部位招募和禁用Polθ.
- PARG 作为关键的激活剂,去除压制性的 PAR 标记,使 Polθ 介导的 DNA 修复成为可能.
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