在调整转录活动时,两个R循环相关的G四复合体的对立作用
Leya Yang1, Chun-Ying Lee1, Tapas Paul1
1Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, United States.
Nucleic acids research
|September 23, 2025
概括
在转录过程中,富含关氨酸 (G) 的序列形成G-四复合体 (G4) 和R-循环. 内分子G4 (IG4) 抑制转录,而分子间G4 (HG4) 增强转录,由HG4/IG4比率决定转录活性.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 在转录过程中,富含关氨酸 (G) 的序列可以形成非正规结构,如G-四复合体 (G4) 和R-循环.
- 这些G4/R循环形成序列 (PQS) 在调节转录中的作用尚未完全理解.
研究的目的:
- 调查不同的PQS如何影响G4/R循环形成和转录动态.
- 阐明分子内G4 (IG4) 和分子间G4 (HG4) R环在转录调节中的不同作用.
主要方法:
- 使用基于凝的测试和单分子光共振能量转移 (smFRET).
- 在T7RNA聚合酶转录过程中测量了RNA合成和同时形成G4和R循环.
- 分析了PQS链接长度对G4结构和转录的影响.
主要成果:
- 两种类型的R环连续形成:IG4 R环,其次是HG4 R环.
- 发现IG4 R环抑制转录,而HG4 R环增强转录.
- 较高的HG4/IG4比率与增加的转录活性正相关.
结论:
- G4/R环的结构动态,特别是HG4/IG4比率,对于控制转录至关重要.
- 在PQS中,短链接器有利于IG4的形成,抑制转录,而长链接器有利于HG4,增强转录.
- 紧紧折叠的PQS阻碍了转化为HG4,从而减少了转录增强.
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