一个保存的PIWI静音复合体检测了piRNA目标的接触
Dipayan De1, Sucharita Sarkar1, Luca F R Gebert1
1Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA, USA.
Molecular cell
|September 5, 2025
概括
PIWI蛋白质使用piRNA来防御自私的遗传元素. 这项研究揭示了一种与PIWI相关的复合物,该复合物识别和分裂转子RNA,为动物提供关键的防御机制.
科学领域:
- 分子生物学
- 遗传学
- 结构生物学
背景情况:
- PIWI蛋白和PIWI相互作用RNA (piRNAs) 是动物生殖细胞中自私基因元素沉默的重要组成部分.
- 通过piRNA引导的转体子识别激活PIWI蛋白质进行防御的确切机制尚不完全理解.
研究的目的:
- 阐明PIWI蛋白质对转子体的识别和沉默的分子机制.
- 确定参与piRNA介导的对转子体的防御的蛋白质复合体.
主要方法:
- 生物化学测定以描述蛋白质与蛋白质相互作用和酶活性.
- 电子显微镜 (cryo-EM) 来确定复合物的结构基础.
- 结构预测以评估进化保护.
主要成果:
- 在丝虫中发现一种新型的转子子识别复合体,包括Siwi,GTSF1和Maelstrom.
- 证明扩展的piRNA-目标配对诱导Siwi的特定构造,使GTSF1和Maelstrom的招募成为可能.
- 结构分析显示,Maelstrom和GTSF1协同激活Siwi的内核酶活动,从而导致目标RNA分裂和Sindle-E的招募.
结论:
- 这项研究将一种保存的PIWI相关复合体 (PIWI*) 定义为piRNA介导的转子体防御中的关键效应因子.
- 这种PIWI*组装和激活的机制在从海绵到人类的元动物中保持着.
- 这些发现为了解动物如何保护其基因组免受移动遗传因素的影响提供了结构和机制框架.
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