eIF3d和eIF4G2介绍了一个取决于上限但独立于eIF4E的替代翻译启动机制
Jacob N K Quartey1, Dixie J Goss2
1Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, New York, USA; Department of Chemistry, Hunter College of the City University of New York, New York, New York, USA.
The Journal of biological chemistry
|February 19, 2025
概括
一种新型的cap-dependent mRNA转化途径涉及真核启动因子3d (eIF3d) 和真核启动因子4G2 (eIF4G2),绕过了eIF4E的需求,使细胞应激期间的翻译成为可能.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 细胞生物学 细胞生物学
背景情况:
- 细胞mRNA翻译通常需要5'帽结构和细胞启动因子4E (eIF4E).
- 一些细胞mRNA可以独立于eIF4E进行翻译,这表明了替代的翻译机制.
- eIF4G2 (DAP5),一个缺乏eIF4E绑定域的eIF4G1同类体,涉及到eIF4E独立的翻译.
研究的目的:
- 为了研究eIF3d和eIF4G2在cap-dependent mRNA翻译中的作用.
- 量化评估eIF3d和eIF4G2复合体与特定mRNA的结合.
- 阐明这些因素在没有eIF4E的情况下促进翻译的机制.
主要方法:
- 基于光异性质的平衡结合研究,以量化蛋白质-mRNA相互作用.
- 在体外翻译试验中使用 luciferase 记者进行测试.
- 分析mRNA子集及其翻译效率.
主要成果:
- 证明了eIF3d和eIF3d/eIF4G2复合物的直接结合到人类mRNA的一个子集.
- 表明甲基化5'mRNA帽结构对于eIF3d和eIF3d/eIF4G2复合物的识别和招募至关重要.
- 与翻译效率相关的上限识别能力,突出了独立于eIF4E的上限依赖机制.
结论:
- eIF3d和eIF4G2提供了可靠的mRNA翻译的替代途径,特别是在eIF4E被抑制或隔离的情况下.
- 这种新的翻译机制对于细胞生长和在压力期间的生存至关重要.
- 确定了eIF3d和eIF4G2作为调节mRNA翻译的潜在治疗点.
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