Department of Biochemistry & Biophysics, University of California, 600 16th Street, San Francisco, California 94158 2200, USA.
EMBO Rep. 2012 Jun 29;13(7):619-30. doi: 10.1038/embor.2012.78.
The organization of eukaryotic chromosomes into transcriptionally active euchromatin and repressed heterochromatin requires mechanisms that establish, maintain and distinguish these canonical chromatin domains. Post-translational modifications are fundamental in these processes. Monoubiquitylation of histones was discovered more than three decades ago, but its precise function has been enigmatic until recently. It is now appreciated that the spectrum of chromatin ubiquitylation is not restricted to monoubiquitylation of histones, but includes degradatory ubiquitylation of histones, histone-modifying enzymes and non-histone chromatin factors. These occur in a spatially and temporally controlled manner. In this review, we summarize our understanding of these mechanisms with a particular emphasis on how ubiquitylation shapes the physical landscape of chromatin.
真核染色体的组织被分为转录活跃的常染色质和受抑制的异染色质，这需要建立、维持和区分这些规范染色质结构域的机制。翻译后修饰在这些过程中是至关重要的。组蛋白的单泛素化在三十多年前就被发现了，但直到最近，其确切功能才变得扑朔迷离。现在人们已经意识到，染色质泛素化的范围不仅限于组蛋白的单泛素化，还包括组蛋白、组蛋白修饰酶和非组蛋白染色质因子的降解泛素化。这些修饰是在空间和时间上受到控制的。在这篇综述中，我们总结了对这些机制的理解，特别强调了泛素化如何塑造染色质的物理景观。
