在拼接之前,queuosine被纳入前体tRNA中.
Wei Guo1,2,3, Igor Kaczmarczyk4,5, Kevin Kopietz6
1Faculty of Biosciences, Heidelberg University, Heidelberg, Germany.
Nature communications
|July 31, 2025
概括
新转录的tRNA分子需要修改功能. 这项研究表明,queuosine (Q) 修饰发生在eukaryotes的tRNA拼接之前,澄清了tRNA成熟的关键步骤.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 转移RNA (tRNA) 分子经历了广泛的转录后修改,才能变得功能性.
- 素 (Q) 是特定tRNA的位置34的关键修饰,特别是那些具有GUN抗的tRNA.
- 细胞tRNATyr前体含有反子循环中的内基序列,需要非正规拼接.
研究的目的:
- 调查tRNA拼接和tRNATyr中的Q修饰之间的时间关系.
- 为了确定Q整合是否在删除内基序列之前或之后.
- 阐明这些必不可少的tRNA成熟阶段的等级协调.
主要方法:
- 在体外和体内生物化学测定.
- 在多个模型生物 (老鼠,人类,,虫) 中分析tRNATyr前体.
- 单颗粒冷电子显微镜 (cryo-EM) 的前tRNATyr与QTRT1/2复合体.
主要成果:
- 在剪接之前,含有Intron的tRNATyr前体被用queuosine (Q) 或galactosyl-queuosine (galQ) 修改.
- 这种Q-修饰的序列,其次是拼接,在各种真核生物物种中保持着.
- 克里奥-EM证实,前tRNATyr是QTRT1/2复合物的基质,这是负责Q整合的酶.
结论:
- 这项研究建立了tRNA成熟的等级顺序,Q-修改在tRNATyr的tRNA拼接之前.
- 这一发现澄清了以前难以捉摸的细胞tRNA处理和功能化的方面.
- 这种保存的机制突显了真核细胞中协调的tRNA成熟路径的重要性.
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