内生p21水平通过抑制多余和抑制新生的DNA合成来保护基因组稳定性
Nicolás L Calzetta1, Sabrina F Mansilla1, Candelaria Mares Ahlers1
1Fundación Instituto Leloir (IIBBA-CONICET), Buenos Aires, Argentina.
Science advances
|October 8, 2025
概括
内源的p21水平调节DNA合成速率和基因组稳定性. 不足的p21通过启用替代DNA聚合酶来促进不稳定性,而足够的p21通过PCNA结合来阻止这种情况.
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:
- 对于完整的DNA复制来说,DNA合成速度至关重要.
- 在调节DNA合成和保持基因组稳定性方面,p21起着至关重要的作用.
- 在DNA复制中,p21的功能是复杂的,并且取决于环境.
研究的目的:
- 阐明p21在控制新生DNA合成速度中的作用.
- 为了研究不同水平的p21如何影响DNA复制途径.
- 了解p21表达,DNA合成和染色体不稳定之间的联系.
主要方法:
- 在不同的p21表达水平下评估新生的DNA合成速率.
- 研究DNA聚合酶 (Pol ι,PrimPol,Pol κ) 和p53.3的参与.
- 分析p21对不同细胞环境中的染色体稳定性的影响,包括p53-null细胞.
主要成果:
- 在正常复制过程中,p21促进新生的DNA合成与Pol ι/p53复合体.
- 下调的p21导致更长,不连续的DNA合成,由PrimPol.
- 完全消除p21导致较短,持续的DNA合成,依赖于Pol κ.
- 两种PrimPol和Pol κ介导的合成都可以诱导染色体的不稳定性.
- 在p53-null细胞中的残留p21影响了PrimPol/Pol κ参与和随后的不稳定性.
结论:
- 固有的p21水平,即使低于CDK抑制值,对于防止基因组不稳定性至关重要.
- 通过结合PCNA,p21防止了基因组的不稳定,从而限制了PrimPol和Pol κ在新生DNA合成中的作用.
- 这些发现突出了p21作为DNA复制忠实性和基因组完整性的关键调节者.
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