在不受干扰的条件下,BRCA1/BARD1无处不在地化PCNA,以促进持续的DNA合成
Daniel Salas-Lloret1, Néstor García-Rodríguez2,3, Emily Soto-Hidalgo3
1Department of Cell and Chemical Biology, Leiden University Medical Centre, Leiden, The Netherlands.
Nature communications
|May 20, 2024
概括
对于DNA修复或Olaparib耐药性来说,BRCA1/BARD1 E3活动并不必不可少. 然而,它使PCNA无处不在,防止DNA缺口和促进复制,突出其在同源重组中的作用.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 癌症研究 癌症研究
背景情况:
- 瘤抑制基因BRCA1的缺陷与遗传性乳腺癌和卵巢癌有关.
- 与BARD1一起的BRCA1具有对DNA修复途径至关重要的泛素E3结合酶活性.
- 关于BRCA1/BARD1 E3活性在瘤抑制和DNA修复中的确切作用仍在争论中.
研究的目的:
- 调查BRCA1/BARD1泛素E3活性对同源重组 (HR) 和Olaparib耐药性的必要性.
- 为了识别BRCA1/BARD1复合体的直接无处不在基质.
- 阐明BRCA1/BARD1 E3活性在DNA复制和基因组稳定中的作用.
主要方法:
- 使用TULIP2方法直接识别E3特异性无处可见基质.
- 评估了BRCA1/BARD1 E3活性对同源重组和对Olaparib的反应的影响.
- 在未受到干扰的条件下,独立于RAD18.1,研究了BRCA1/BARD1的PCNA泛化.
主要成果:
- 对于同源重组和Olaparib耐药性而言,BRCA1/BARD1泛素E3活性是不可或缺的.
- 鉴定PCNA为直接基质,被BRCA1/BARD1泛基化.
- 通过BRCA1/BARD1进行PCNA无化,可以防止在复制过程中形成单链DNA间隙,并确保持续的DNA合成.
结论:
- 对于BRCA1/BARD1在HR或药物耐药性方面的正规作用,不需要UBIQUITIN E3结合酶活性.
- 在DNA复制过程中,BRCA1/BARD1直接 ubiquitinates PCNA,这是维持基因组完整性的关键步骤.
- 这些发现揭示了BRCA1/BARD1 E3活性在促进DNA合成和稳定性方面的新功能,独立于其在HR中的作用.
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