结构开关:细胞内G四重复体调节了Deinococcus radiodurans中的DNA修复和基因组维护
Himani Tewari1,2, Shruti Mishra1,2, Swathi Kota1,2
1Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.
mBio
|September 29, 2025
概括
在Deinococcus radiodurans中形成关氨酸四重体 (G4s),并动态调节基因表达和DNA修复. 它们的形成和分辨率受到金属离子和修复蛋白的影响,影响基因组稳定性.
科学领域:
- * 分子生物学 * 分子生物学
- * 结构生物学 * 结构生物学
- * 极端生物生物学
背景情况:
- * 关氨酸四重复体 (G4s) 是核酸二次结构,在真核生物中起着调节作用,但它们在真核生物中的活体功能在很大程度上是未知的.
- *Deinococcus radiodurans是一种因其抗辐射能力而闻名的极端分子,具有富含GC的基因组,有许多潜在的G-四重复形成序列.
- *以前的研究表明,G4结合联体在D.radiodurans在辐射后恢复 (PIR) 期间增加对电离辐射的敏感性.
研究的目的:
- * 研究Deinococcus radiodurans中G4结构的体内形成,动力学和调节作用.
- *阐明G4结构对基因表达,DNA修复和在正常和压力条件下的基因组维护的影响.
- * 探索双价离子 (Mn2+,Mg2+) 和G4溶解蛋白对G4稳定性和细胞过程的影响.
主要方法:
- *对D. radiodurans.的潜在G-四倍体形成序列进行了体外折叠研究.
- * 检测体内G4形成使用thioflavin T和抗G-quadruplex抗体对DNA损伤剂的反应.
- *在各种条件下分析基因表达,8-oxo关氨酸水平和DNA修复动态 (例如,存在G4结合药物,没有RecQ).
主要成果:
- *体外研究表明,G4结构采用不同的拓,受二价离子的影响;Mn2+破坏了G4的稳定性,而Mg2+支持了它们的形成.
- *在D. radiodurans中检测到体内G4形成和动态,在玛辐射后观察到的最高水平.
- *G4结构根据其基因组位置 (5'或3'端) 不同调节基因表达.
- * PIR期间的G4结合药物阻止了G4动态,增加了8-oxo关氨酸,并延迟了DNA修复.
- *没有RecQ蛋白导致G4积累,并增加了基因组的不稳定性.
结论:
- *D. radiodurans体内体内G4的形成是动态的,并且根据细胞条件,包括压力和金属离子度而有所变化.
- * 在这种细菌中,G4结构在调节基因表达,DNA修复和基因组维护方面发挥着重要作用.
- *G4的结构动力学对于细胞对DNA损伤的反应和维护D. radiodurans基因组稳定性至关重要.
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