RQC 机器的故障导致蛋白质聚合和蛋白质毒性应激
Young-Jun Choe1, Sae-Hun Park1, Timm Hassemer1
1Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
Nature
|March 3, 2016
概括
由于缺少止子导致核糖体停滞导致蛋白质聚合和神经退行. 核糖体质量控制 (RQC) 机制通常可以防止这种情况发生,但其故障会破坏蛋白质平衡.
科学领域:
- 分子生物学
- 细胞生物学
- 神经科学
背景情况:
- 没有停止子的信使RNA的翻译会导致核糖体停滞和非停止蛋白质的产生.
- 核糖体质量控制 (RQC) 机制通常针对这些停滞的新生链进行蛋白质体降解.
- RQC功能失效与神经退行有关,但潜在的机制尚不清楚.
研究的目的:
- 调查由核糖体停滞的多引起蛋白质毒性的机制.
- 阐明 E3 泛素连接酶 Ltn1p 和其他 RQC 组件在处理停滞蛋白质中的作用.
- 了解蛋白质质量控制中的缺陷如何导致神经退行过程.
主要方法:
- 使用酵母模型研究删除Ltn1p的后果,这是一个关键的RQC组件.
- 分析了缺乏Ltn1p的酵母中的蛋白质聚合物和含量.
- 研究了C端氨酸/氨酸尾和聚氨酸通道在聚合物形成中的作用.
主要成果:
- 在酵母中删除Ltn1p会导致从停滞的蛋白质中形成耐洗剂聚合物和内含物.
- 聚合物形成取决于Rqc2p添加的C端氨酸/三氨酸尾部和不间断蛋白质的多氨酸通道.
- 这些聚合物隔离细胞,干扰一般蛋白质质量控制途径.
结论:
- 核糖体停滞的多可以形成破坏蛋白质稳定性的有毒聚合物.
- 包括Ltn1p和Rqc2p在内的RQC机制在防止停滞蛋白的聚合和毒性方面发挥着至关重要的作用.
- 这些发现提供了RQC功能障碍,蛋白质聚合和神经退行之间的机制联系.
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