Abstract:
The post-translational modification of proteins with ubiquitin plays a central role in nearly all aspects of eukaryotic biology. Historically, studies have focused on the conjugation of ubiquitin to lysine residues in substrates, but it is now clear that ubiquitylation can also occur on cysteine, serine, and threonine residues, as well as on the N-terminal amino group of proteins. Paradigm-shifting reports of non-proteinaceous substrates have further extended the reach of ubiquitylation beyond the proteome to include intracellular lipids and sugars. Additionally, results from bacteria have revealed novel ways to ubiquitylate (and deubiquitylate) substrates without the need for any of the enzymatic components of the canonical ubiquitylation cascade. Focusing mainly upon recent findings, this review aims to outline the current understanding of non-lysine ubiquitylation and speculate upon the molecular mechanisms and physiological importance of this non-canonical modification.
摘要:
具有泛素的蛋白质的翻译后修饰在真核生物学的几乎所有方面都起着核心作用。历史上,研究集中在泛素与底物中赖氨酸残基的缀合,但现在很清楚,泛素化也可以发生在半胱氨酸上,丝氨酸,和苏氨酸残基,以及蛋白质的N端氨基。非蛋白质底物的范式转变报道进一步扩展了泛素化的范围,超出了蛋白质组,包括细胞内脂质和糖。此外,来自细菌的结果揭示了新的方法来泛素化(和去泛素化)底物,而不需要任何经典泛素化级联的酶成分。主要关注最近的发现,这篇综述旨在概述目前对非赖氨酸泛素化的理解,并推测这种非规范修饰的分子机制和生理重要性。