Protein Metabolism Medical Research Center and Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 110-799, Korea; Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul 110-799, Korea.
Protein Metabolism Medical Research Center and Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 110-799, Korea; Technion Integrated Cancer Center (TICC), The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel.
Trends Biochem Sci. 2017 Nov;42(11):873-886. doi: 10.1016/j.tibs.2017.09.002. Epub 2017 Sep 22.
The conjugation of the 76 amino acid protein ubiquitin to other proteins can alter the metabolic stability or non-proteolytic functions of the substrate. Once attached to a substrate (monoubiquitination), ubiquitin can itself be ubiquitinated on any of its seven lysine (Lys) residues or its N-terminal methionine (Met1). A single ubiquitin polymer may contain mixed linkages and/or two or more branches. In addition, ubiquitin can be conjugated with ubiquitin-like modifiers such as SUMO or small molecules such as phosphate. The diverse ways to assemble ubiquitin chains provide countless means to modulate biological processes. We overview here the complexity of the ubiquitin code, with an emphasis on the emerging role of linkage-specific degradation signals (degrons) in the ubiquitin-proteasome system (UPS) and the autophagy-lysosome system (hereafter autophagy).
泛素化是将 76 个氨基酸的蛋白质泛素连接到其他蛋白质上，这可以改变底物的代谢稳定性或非蛋白水解功能。一旦连接到底物上（单泛素化），泛素本身可以在其七个赖氨酸（Lys）残基或其 N 端甲硫氨酸（Met1）上进行泛素化。一个单一的泛素聚合物可能包含混合键和/或两个或更多分支。此外，泛素可以与 SUMO 等泛素样修饰物或磷酸盐等小分子结合。组装泛素链的多种方式为调节生物过程提供了无数的方法。我们在这里概述了泛素码的复杂性，重点介绍了连接特异性降解信号（degrons）在泛素-蛋白酶体系统（UPS）和自噬溶酶体系统（自噬）中的新兴作用。
