核糖体扩张段通过核糖体蛋白的N端处理,有助于翻译忠实性
Riku Nagai1,2, Olivia L Milam1,2, Tatsuya Niwa3
1Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, United States.
Nucleic acids research
|May 28, 2025
概括
细胞核糖体通过在核糖体蛋白上处理启动子 metionin (iMet) 来保持高的翻译保真度. 这防止了核糖体的结构变化,并确保了精确的蛋白质合成.
科学领域:
- 分子生物学分子生物学
- 核糖体功能 核糖体功能
- 蛋白质合成 蛋白质合成
背景情况:
- 细胞核糖体具有比 prokaryotic 核糖体更高的mRNA 翻译忠实性,这归因于细胞特异性核糖体RNA (rRNA) 插入.
- 在60S子单元上的扩展段27L (ES27L) 定了甲氨基酶 (MetAP),通过处理启动元甲 (iMet) 来提高保真度.
- 之前,将iMet处理与翻译准确性联系在一起的确切机制尚不清楚.
研究的目的:
- 为了研究启动子 metionin (iMet) 处理如何影响真核核糖核酶体翻译忠实性.
- 阐明 metionin aminopeptidase (MetAP) 核糖体关联在防止iMet 保持在核糖体蛋白 (RP) 上的作用.
主要方法:
- 使用酵母体内翻译 (IVT) 系统来评估翻译准确性.
- 开发了一种新的方法来监测iMet处理 in vivo.
- 来自酵母菌株的净化核糖体,具有改变的MetAP关联或活性 (ES27L Δb1-4, Δmap1).
- 重建的IVT系统与iMet-保留的核糖体子单元和野生类型的转化因子.
主要成果:
- 同翻译iMet处理的抑制没有影响正在进行的合成忠实度.
- 缺乏MetAP核糖体关联 (ES27L Δb1-4) 或主要酵母 MetAP (Δmap1) 的核糖体显示出对核糖体蛋白 (RPs) 的Imet保留增加.
- 在40S核糖体子单元上的iMet保留被确定为重组系统中翻译错误的原因.
结论:
- 扩展段27L (ES27L) 对于调节MetAP与核糖体的关联至关重要,微调关键RP的Imet处理.
- 在RP上保留iMet可以扭曲核糖体结构,损害功能并导致翻译错误.
- 适当的iMet处理对于维护真核核糖体核糖体的结构完整性和功能精度至关重要.
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