通过p53调节LINE1逆转移素衍生的R循环
Pratyashaa Paul1, Arun Kumar1, Ankita Subhadarsani Parida1
1Department of Biological Sciences, Indian Institute of Science Education and Research Berhampur, Berhampur, Odisha, India.
The Journal of biological chemistry
|January 19, 2025
概括
瘤抑制剂p53通过沉默长间隔核元素1 (LINE1) 转位子来防止基因组的不稳定. 它抑制了RNA-DNA混合体 (R-循环) 的形成,并与基因组甲基转移酶一起工作以抑制L1激活.
科学领域:
- 遗传学 是一个遗传学.
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
背景情况:
- 长间隔核元素1 (LINE1) 逆转移子在人类基因组中很丰富,可以在癌症中变得活跃.
- 瘤抑制剂p53已被证明可以使LINE1元素沉默,但机制尚未完全理解.
- RNA-DNA混合体 (R环) 是LINE1逆转换中的中间体.
研究的目的:
- 研究LINE1元素及其中间体的p53介导抑制的分子机制.
- 探索p53在调节LINE1衍生的R循环中的作用.
- 了解p53如何与表观遗传修饰剂合作控制LINE1活动.
主要方法:
- 用DNA-RNA免疫沉降测序 (DRIP-seq) 来检测R循环.
- 使用p53-null (p53-/-) 和野生类型 (WT) 细胞的实验.
- 使用基因素脱乙酶抑制剂 (HDACi) 和逆转录酶抑制剂进行治疗.
- 在LINE1位点对基因子修饰的分析.
主要成果:
- 在p53-/-细胞中,R环积累 (cis和trans) 增加,与HDAC抑制剂协同作用.
- 反转录酶抑制降低了R循环水平,证实了逆转换的作用.
- 在WT细胞中,HDAC抑制剂的退出导致LINE1抑制,标志着抑制性基因素标记 (H3K9me3,H3K27me3) 和减少的激活标记.
- p53与SETDB1和G9A合作,将H3K9me3沉积在LINE1的促销器上,使转位子沉默.
结论:
- p53在防止LINE1衍生的R循环的形成方面发挥着新的作用.
- 通过与基因组甲基转移酶合作,p53抑制过度活化的LINE1元素.
- 这些发现突显了p53在通过LINE1调节来维持基因组稳定的关键功能.
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