Ohtake Fumiaki, Tsuchiya Hikaru
Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Sciences, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
J Biochem. 2017 Feb 1;161(2):125-133. doi: 10.1093/jb/mvw088.
Ubiquitylation is an essential post-translational modification (PTM) of proteins with diverse cellular functions. Polyubiquitin chains with different topologies have different cellular roles, and are referred to as a 'ubiquitin code'. Recent studies have begun to reveal that more complex ubiquitin architectures function as important signals in several biological pathways. These include PTMs of ubiquitin itself, such as acetylated ubiquitin and phospho-ubiquitin. Moreover, important roles for heterogeneous polyubiquitin chains, such as mixed or branched chains, have been reported, which significantly increase the diversity of the ubiquitin code. In this review, we describe mass spectrometry-based methods to characterize the ubiquitin signal. We also describe recent advances in our understanding of complex ubiquitin architectures, including our own findings concerning ubiquitin acetylation and branching within polyubiquitin chains.
泛素化是一种对具有多种细胞功能的蛋白质进行的重要翻译后修饰（PTM）。具有不同拓扑结构的多聚泛素链具有不同的细胞作用，被称为“泛素密码”。最近的研究开始揭示，更复杂的泛素结构在几种生物途径中作为重要信号发挥作用。这些包括泛素自身的翻译后修饰，如乙酰化泛素和磷酸化泛素。此外，已经报道了异质多聚泛素链（如混合链或分支链）的重要作用，这显著增加了泛素密码的多样性。在这篇综述中，我们描述了基于质谱的方法来表征泛素信号。我们还描述了我们对复杂泛素结构理解的最新进展，包括我们自己关于泛素乙酰化和多聚泛素链内分支的发现。
