Institute of Molecular Biotechnology (IMBA), Vienna Biocenter (VBC), Austria.
Chapman University School of Pharmacy (CUSP), Harry and Diane Health Science Campus, Chapman University, Irvine, CA, USA.
FEBS J. 2018 Aug;285(15):2746-2761. doi: 10.1111/febs.14478. Epub 2018 Apr 30.
Ubiquitin modification (ubiquitination) of target proteins can vary with respect to chain lengths, linkage type, and chain forms, such as homologous, mixed, and branched ubiquitin chains. Thus, ubiquitination can generate multiple unique surfaces on a target protein substrate. Ubiquitin-binding domains (UBDs) recognize ubiquitinated substrates, by specifically binding to these unique surfaces, modulate the formation of cellular signaling complexes and regulate downstream signaling cascades. Among the eight different homotypic chain types, Met1-linked (also termed linear) chains are the only chains in which linkage occurs on a non-Lys residue of ubiquitin. Linear ubiquitin chains have been implicated in immune responses, cell death and autophagy, and several UBDs - specific for linear ubiquitin chains - have been identified. In this review, we describe the main principles of ubiquitin recognition by UBDs, focusing on linear ubiquitin chains and their roles in biology.
泛素修饰（ubiquitination）的目标蛋白可以在链长、连接类型和链形式方面有所不同，如同源、混合和分支泛素链。因此，泛素化可以在靶蛋白底物上产生多个独特的表面。泛素结合结构域（UBD）通过特异性结合这些独特的表面来识别泛素化的底物，调节细胞信号复合物的形成，并调节下游信号级联反应。在八种不同的同质链类型中，Met1 连接（也称为线性）链是唯一在泛素的非赖氨酸残基上发生连接的链。线性泛素链已被牵涉到免疫反应、细胞死亡和自噬中，并且已经鉴定出几种特异性识别线性泛素链的 UBD。在这篇综述中，我们描述了 UBD 识别泛素的主要原则，重点介绍了线性泛素链及其在生物学中的作用。
