基因断裂的弥合激活了PARP2-HPF1以修改色素
Silvija Bilokapic1, Marcin J Suskiewicz2, Ivan Ahel2
1Department of Structural Biology, St Jude Children's Research Hospital, Memphis, TN, USA.
Nature
|September 17, 2020
概括
研究人员揭示了PARP2-HPF1如何通过弥合核子组来识别DNA断裂,这是双链断裂修复的关键步骤. 这种对多基酶 (PARP) 激活的结构洞察力可能会改善癌症疗法.
科学领域:
- 分子生物学
- 结构生物学
- 生物化学
背景情况:
- DNA 链断裂触发了多基酶 (PARP1/2) 对DNA损伤反应的招募.
- 对于PARP1/2来说,HPF1对于修改血清残留至关重要,从而促进染色质变化和修复因子的招募.
- 了解PARP酶对染色体中的DNA断裂的识别对于DNA修复机制至关重要.
研究的目的:
- 阐明PARP酶识别染色体内DNA断裂的分子机制.
- 确定PARP2-HPF1与DNA断裂中的核细胞相互作用的结构基础.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定与核体结合的人类PARP2-HPF1的结构.
- 结构分析的重点是PARP2-HPF1,核细胞和破碎的DNA之间的相互作用.
主要成果:
- 该结构揭示了PARP2-HPF1连接了两个破碎的DNA,用于结合,说明了双链断裂修复的早期步骤.
- 通过PARP2-HPF1结合,PARP2的形状发生变化,导致DNA断裂识别并激活催化域.
- 证据表明,PARP2通过NAD+和基质交换的结构状态循环,可能使染色体的过程作用成为可能.
结论:
- 这项研究揭示了PARP2-HPF1在识别DNA断裂和启动修复方面的结构机制.
- 描述的PARP激活和催化周期为PARP抑制剂耐药性提供了洞察力.
- 这些发现将指导改进的PARP抑制剂用于癌症治疗.
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