Ubiquitylation is a critical post-translational modification that controls a wide variety of processes in eukaryotes. Ubiquitin chains of different topologies are specialized for different cellular functions and control the stability, activity, interaction properties, and localization of many different proteins. Recent work has highlighted a role for branched ubiquitin chains in the regulation of cell signaling and protein degradation pathways. Similar to their unbranched counterparts, branched ubiquitin chains are remarkably diverse in terms of their chemical linkages, structures, and the biological information they transmit. In this review, we discuss emerging themes related to the architecture, synthesis, and functions of branched ubiquitin chains. We also describe methodologies that have recently been developed to identify and decode the functions of these branched polymers.

泛素化是一种关键的翻译后修饰，可控制真核生物中的各种过程。不同拓扑结构的泛素链专门用于不同的细胞功能，并控制许多不同蛋白质的稳定性、活性、相互作用特性和定位。最近的工作强调了分支泛素链在调节细胞信号传导和蛋白质降解途径中的作用。与其未分支的对应物类似，分支泛素链在化学键、结构和传递的生物信息方面非常多样化。在这篇综述中，我们讨论了与分支泛素链的架构、合成和功能相关的新兴主题。