选择性核糖体分析揭示了活体中触发因子的共翻译伴侣作用
Eugene Oh1, Annemarie H Becker, Arzu Sandikci
1Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
Cell
|December 14, 2011
概括
研究人员开发了一种新的核糖体分析方法来追踪蛋白质加工因子. 研究表明,触发因子 (TF) 主要与外膜蛋白结合,并在~100个氨基酸被翻译后参与核糖体,从而挑战了先前的模型.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 蛋白质的生物发生.
背景情况:
- 从核糖体中出现的新生多与各种处理,准和折叠因素相互作用.
- 了解这些相互作用的精确时间和特异性对于蛋白质生物生成至关重要.
- 之前的体外研究表明,触发因子 (TF) 预先与核糖体结合.
研究的目的:
- 开发一种选择性核糖体分析策略,用于全球监测与新生多的因子参与.
- 研究大肠杆菌触发因子 (TF) 的体内结合动力学和基质特异性.
- 阐明TF在协译蛋白转位和加工中的作用.
主要方法:
- 开发了一种选择性核糖体分析技术,以在体内监测因子参与.
- 应用该方法研究大肠杆菌中伴侣触发因子 (TF).
- 分析了TF损失和过剩对外膜蛋白质生物发生和共翻译转位的影响.
主要成果:
- 确定了β-桶外膜蛋白作为TF的突出基质.
- 证明TF仅在大约100个氨基酸被翻译后才能在体内激活核糖体,这与体外发现相矛盾.
- 观察到广泛的外膜缺陷和TF损失时过早的转换转移.
- 发现过多的TF干扰了在共翻译处理过程中N终端甲基甲酸甲基因的去除.
结论:
- TF的体内结合动力学不同于体内预测,在多合成中发生的时间较晚.
- TF在外膜蛋白质的生物发生中发挥着关键作用.
- 支持一个分类模型,其中蛋白质生物发生取决于顺序的,微调的因子参与.
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