Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
Front Biosci (Landmark Ed). 2012 Jan 1;17(3):1051-78. doi: 10.2741/3973.
Histones are subject to several post-translational modifications, which act to regulate gene expression and other processes on the DNA template. One such modification is the addition of a single ubiquitin moiety, which has been reported to influence chromatin dynamics and exhibit cross-talk with other histone modifications. Mono-ubiquitylation of H2B has been reported in eukaryotes as divergent as budding yeast, flies and humans, and is linked to transcriptional activation and gene silencing. Furthermore, ubiquitylation of H2A is also important for transcriptional repression in higher eukaryotes, and both histones play key roles in DNA repair. In this review, we will give an overview of the enzymes important for ubiquitylation and deubiquitylation of the various histone species, before examining the role of ubiquitylated histones in shaping the chromatin landscape and thus controlling the accessibility of DNA to effector proteins, through putative roles in promoting histone-histone interactions and stabilizing the structure of nucleosomes. We will finally discuss other processes reported to involve ubiquitylation of histones, including DNA repair, recombination and mRNA processing, underlining the diverse actions of these modifications.
组蛋白会受到多种翻译后修饰，这些修饰作用可以调节 DNA 模板上的基因表达和其他过程。其中一种修饰是添加单个泛素分子，它被报道可以影响染色质动力学，并与其他组蛋白修饰发生交叉对话。在真核生物中，从芽殖酵母、果蝇到人类，H2B 的单泛素化都有报道，与转录激活和基因沉默有关。此外，H2A 的泛素化对于高等真核生物中的转录抑制也很重要，这两种组蛋白在 DNA 修复中都起着关键作用。在这篇综述中，我们将概述参与各种组蛋白泛素化和去泛素化的酶，然后研究泛素化组蛋白在塑造染色质景观以及通过促进组蛋白-组蛋白相互作用和稳定核小体结构从而控制 DNA 与效应蛋白的可及性方面的作用，以此来检验泛素化组蛋白的作用。最后，我们将讨论其他报道的涉及组蛋白泛素化的过程，包括 DNA 修复、重组和 mRNA 加工，强调这些修饰的多种作用。
