酵母EndoG通过降解核外DNA物种来防止基因组不稳定
Yang Yu1, Xin Wang2,3, Jordan Fox1
1Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, USA.
Nature communications
|September 3, 2024
概括
像Nuc1这样的酵母核酶通过降解细胞质DNA来防止核基因组的不稳定性. 这一过程限制了线粒体DNA (mtDNA) 和逆转移子cDNA的插入,从而保持了基因组的完整性.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 细胞生物学 细胞生物学
背景情况:
- 细胞质中的核外DNA,如线粒体DNA (mtDNA) 和逆转移体cDNA,可以在甲基动物中引发无菌炎症.
- 外核DNA降解在防止核基因组不稳定性方面的作用在很大程度上仍未被探索.
研究的目的:
- 调查核酶对核外DNA的降解是否能防止酵母中的核基因组不稳定.
- 阐明酵母核酶,特别是Nuc1 (EndoG) 处理核外DNA及其对基因组稳定性的特定机制.
主要方法:
- 在酵母中利用基于安普利康序列的方法来分析数百万个双链断裂 (DSB) 修复产品.
- 检查了DNA修复机制,包括在不分裂的静态相细胞中进行Pol4介导的非同类末端结合 (NHEJ).
- 研究了酵母核酶Nuc1在调节核外DNA转移和集成到核中的作用.
主要成果:
- 非同源端结合 (NHEJ) 活性在静止阶段酵母中增加,导致频繁插入短DNA片段 (1-3核酸),线粒体DNA (mtDNA) 和逆转移子cDNA.
- 酵母EndoG (Nuc1) 限制了逆转移子cDNA和非常长mtDNA (>10 kb) 的核插入,防止不稳定的圆形DNA的形成.
- Nuc1促进短核mtDNA插入的形成 (NUMTs,~45-200 bp) 并调节衰老和半分裂期间的核外DNA转移.
结论:
- 通过降解潜在有害的逆转移子cDNA和长 mtDNA片段,Nuc1 保持了基因组的稳定性.
- 短NUMT可能来自不完全降解的mtDNA,这表明核酶在管理核外DNA残留物中的作用.
- 核酶对核外DNA的降解是维持核基因组稳定的关键机制.
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