在Saccharomyces cerevisiae中C端序列稳定性分析揭示了保护性蛋白质质量控制途径
Sophia Hasenjäger1, Andrea Bologna2, Lars-Oliver Essen3
1Department of Biology/Genetics, Philipps-University Marburg, Marburg, Germany.
The Journal of biological chemistry
|August 18, 2023
概括
蛋白质质量控制通过检查其C端序列来识别和降解有缺陷的蛋白质. 这项研究揭示了蛋白质末端的特定氨基酸模式,这些蛋白质标志着不稳定性,指导降解途径.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 蛋白质质量控制 (PQC) 通过消除错误折叠或损坏的蛋白质来维持细胞健康.
- 无素-蛋白酶体系统是一个关键的PQC通路,通常针对蛋白质末端.
- C端氨基酸的变化可能是各种细胞过程的结果,影响蛋白质的稳定性.
研究的目的:
- 研究C端氨基酸序列在蛋白质稳定性和降解中的作用.
- 为了识别特定的氨基酸特征,信号蛋白质缺陷.
- 了解蛋白质平衡中C端序列选择的进化基础.
主要方法:
- 在芽酵母中使用了一种记者蛋白系统,随机采集C终端 (CtPC) 的光控制暴露.
- 分析了氨基酸身份,位置和组成在C端位置 (-5至-1) 对蛋白质稳定性的影响.
- 研究了特定的PQC组件的参与,包括无素蛋白联酶Doa10和SCFDas1.
主要成果:
- 在C端确定了特定的氨基酸残留物和序列组合,使蛋白质稳定或不稳定.
- 证明了这些破坏稳定的C端降解子 (CtPC-降解子) 在蛋白质之间是可转移的.
- 观察了细胞和核蛋白中对破坏稳定的C端残留的进化选择.
- 表明停止-codon读透通常具有破坏稳定的C termini.
结论:
- C终端序列是蛋白质稳定性的关键决定因素,也是PQC的目标.
- 广泛的C端序列变异被PQC机制识别,保护蛋白质组.
- 这些发现揭示了对具有异常C termini的蛋白质的复杂监控系统.
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