通过氧化脱硫来调节tRNA修饰的转化调节
Yufeng Mo1, Kensuke Ishiguro1,2, Kenjyo Miyauchi1
1Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Japan.
Nature communications
|March 11, 2026
概括
氧化应激可以改变转移RNA (tRNA) 的修饰,特别是xm5s2U到xm5h2U的脱硫. 这种修改会损害tRNA功能,影响人类和哺乳动物细胞中的蛋白质合成和密码子识别.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 转移RNA (tRNA) 修改对于精确的蛋白质合成至关重要.
- 5-Methyl-2-thiouridine (xm5s2U) 是一个关键的tRNA修饰在抗波动位置,提高解码效率.
- 在xm5s2U中的二氧化基基容易发生氧化脱硫,形成4-皮里米丁衍生物 (xm5h2U).
研究的目的:
- 在人类和小鼠组织中识别和确认xm5h2U衍生物的细胞形成.
- 研究xm5h2U修饰对tRNA解码和氨基化发生的功能后果.
- 阐明通过xm5h2U修饰的tRNAs识别改变的编码子的结构基础.
主要方法:
- 刺入实验以确认xm5h2U的细胞形成.
- 在体外翻译系统使用复制的人体系统来评估编码子识别.
- 低温电子显微镜 (cryo-EM) 用于确定核糖体A位点的结构变化.
主要成果:
- 在人类细胞和小鼠组织中发现并证实了xm5h2U衍生物.
- 脱硫的mcm5h2U修饰的tRNA表现出对特定tRNA (lysine,glutamate,glutamine) 的编码子识别受损和氨基化减少.
- 冷EM揭示了由mc5h2U解码的改变AAA/AAG码子在核糖体A位点的结构基础.
结论:
- 氧化脱硫的tRNA修饰动态调节的编码子识别和蛋白质合成.
- 这种机制在人类和哺乳动物细胞中对氧化应激的细胞反应中起作用.
- 这些发现提供了关于tRNA修饰状态如何影响蛋白质合成忠实性的见解.
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