通过mPSF识别低频多化信号的分子基础
Lin Huang1, Hsu-Feng Chu1, Liang Tong1
1Department of Biological Sciences, Columbia University, New York, NY 10027, United States.
Nucleic acids research
|September 10, 2025
概括
这项研究揭示了如何通过哺乳动物多化特异性因子 (mPSF) 识别低频多化信号. 结构分析显示了这些信号的独特结合模式,解释了它们在基因调节中的较低发生率.
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:
- 前mRNA 3'-end 处理依赖于多基化信号 (PAS),这是一个六核酸基因.
- 哺乳动物多化特异性因子 (mPSF) 识别了PAS六合体.
- 虽然AAUAAA和AUAAA占主导地位,但对低频PAS六合体的识别仍然不清楚.
研究的目的:
- 通过mPSF研究识别低频多化信号的分子基础.
- 确定mPSF与各种PAS六合素相互作用的结合亲和性和结构基础.
主要方法:
- 确定多个PAS六分子的结合亲和度 (Kd值).
- 低温电子显微镜 (cryo-EM) 以高分辨率 (3.1 Å和2.5 Å) 解析与AAUAAU和AGUAAA结合的人类mPSF的结构.
主要成果:
- 结合亲和力通常与PAS六合体频率相反相关.
- 观察到低频六合素AAGAAA和AACAAA的良好裂解活性.
- 冷-EM结构显示,低频六合体与AAUAAA类似地结合,具有特定的基基修饰 (例如,AAUAAU中破坏的Hoogsteen基对,AGUAAA的G2基的构造变化) 允许与CPSF30的相互作用.
结论:
- 这项研究阐明了由mPSF.mPSF识别多种多基化信号的基础分子机制.
- 结构洞察力解释了低频PAS变体如何保持功能相互作用,从而导致基因表达调节的复杂性.
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