eIF5B从翻译启动到延长的过渡
Jinfan Wang1, Alex G Johnson1,2, Christopher P Lapointe1
1Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.
Nature
|September 20, 2019
概括
从核糖体释放5B的真核细胞启动因子 (eIF5B) 作为蛋白质合成的检查点. 由GTP水解引发的解离,标志着从翻译启动到延伸的过渡.
科学领域:
- 分子生物学
- 生物化学
- 细胞生物学
背景情况:
- 翻译启动对于蛋白质合成至关重要,通过设置mRNA读取框架来确定蛋白质数量和身份.
- 转化启动的动态,特别是真核细胞的长度过渡,仍然不完全理解.
- 许多翻译启动因子参与了对聚合成的核糖体的准备.
研究的目的:
- 在真核系统中研究晚期翻译启动和过渡到延长的动态.
- 阐明5B真核启动因子 (eIF5B) 在从翻译启动到延长的转变中的作用.
- 了解从翻译启动到延伸的监管机制.
主要方法:
- 使用体外单分子光显微镜.
- 使用纯化的酵母Saccharomyces cerevisiae转化系统.
- 实时监测迟到的翻译启动和过渡到延长的路径.
主要成果:
- 在酵母中,从翻译启动到延伸的转变比大肠杆菌慢.
- 在核糖体子单元结合后,观察到eIF5B在80S核糖体上的停留时间延长.
- 在子单元结合后抑制eIF5B的GTPase活动可以防止eIF5B的解离和随后的延长.
结论:
- eIF5B 分离是从翻译启动到延伸的动力检查点.
- 触发GTP水解的核糖体构造变化可能影响eIF5B的释放.
- 了解这个检查点对于理解真核细胞蛋白质合成调节至关重要.
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