5-甲基细胞氨酸不是哺乳动物细胞中普遍存在的RNA修饰
Jasmin A Dehnen1, Alexander V Gopanenko1, Carola Scholz1
1Institute of Molecular Biology (IMB), Mainz, Germany.
Nature communications
|November 11, 2025
概括
哺乳动物5-formylcytidine (f5C) 主要在线粒体tRNA中发现,而不是mRNA. ALKBH1酶调解了这种修饰,挑战了关于其作用和位置的先前假设.
科学领域:
- 生物化学 生物化学
- 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:
- 在哺乳动物中,RNA修饰5-formylcytidine (f5C) 的研究不足.
- 之前的研究表明mRNA中的f5C水平较低,可能是由于TET/ALKBH1酶对5-methylcytidine (m5C) 的氧化或去甲基化.
研究的目的:
- 在哺乳动物RNA中准确量化和定位f5C.
- 研究负责f5C生成的酶,特别是TET和ALKBH1.1.
- 为了澄清f5C在哺乳动物细胞中的功能作用.
主要方法:
- 使用了液体染色学-双重质谱法 (LC-MS/MS) 和化学辅助测序.
- 开发了一种新方法,FIBo-seq,以提高f5C检测的特异性和灵敏性.
- 对小鼠胚胎干细胞 (mESCs) 进行了分析.
主要成果:
- 发现在pyridine-borane-sequencing方法错误地识别了其他RNA修饰 (ac4C) 和cytidines作为f5C.
- 没有证据支持TET酶在f5C生成中的作用;ALKBH1的作用得到证实.
- 在mRNA中没有检测到f5C;大多数存在于线粒体tRNA甲氨酸 (mt-tRNAMet).
结论:
- 哺乳动物f5C主要位于mt-tRNAMet中,并且依赖ALKBH1.
- 以前在mRNA中发现f5C的发现很可能是测序方法的工件.
- 在哺乳动物中,f5C可能在tRNA之外没有指导性功能.
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