Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK.
Trends Biochem Sci. 2011 Jul;36(7):355-63. doi: 10.1016/j.tibs.2011.04.004. Epub 2011 Jun 7.
Polyubiquitin chains are assembled via one of seven lysine (Lys) residues or the N terminus. The cellular roles of Lys48- and Lys63-linked polyubiquitin have been extensively studied; however, the cellular functions of Lys11-linked chains are less well understood. Recent insights into Lys11-linked ubiquitin chains have revealed their important function in cell cycle control. Additionally, Lys11 linkages have been identified in the context of mixed chains in many other cellular pathways. In this review, we introduce the specific enzymes that mediate Lys11-linked chain assembly and disassembly, and discuss the diverse cellular processes in which Lys11 linkages participate. Notably, mechanistic insights have revealed how the E2 ubiquitin-conjugating enzyme UBE2S achieves its Lys11 linkage specificity, and two structures of Lys11-linked polyubiquitin highlight the dynamic nature of this compact chain type.
多聚泛素链通过 7 个赖氨酸（Lys）残基之一或 N 末端进行组装。Lys48- 和 Lys63 连接的多聚泛素的细胞作用已得到广泛研究；然而，Lys11 连接的链的细胞功能则了解较少。最近对 Lys11 连接的泛素链的深入了解揭示了它们在细胞周期控制中的重要功能。此外，在许多其他细胞途径的混合链中也鉴定出了 Lys11 连接。在这篇综述中，我们介绍了介导 Lys11 连接链组装和拆卸的特定酶，并讨论了 Lys11 连接参与的各种细胞过程。值得注意的是，机制研究揭示了 E2 泛素缀合酶 UBE2S 如何实现其 Lys11 连接特异性，并且 Lys11 连接的多聚泛素的两个结构突出了这种紧凑链类型的动态性质。
