Howard Hughes Medical Institute, New York University Langone Health, New York, New York 10016, USA.
Department of Biochemistry and Molecular Pharmacology, New York University Langone Medical School, New York, New York 10016, USA.
Genes Dev. 2021 Jan 1;35(1-2):40-58. doi: 10.1101/gad.344531.120.
Major advances in the chromatin and epigenetics fields have uncovered the importance of core histones, histone variants and their post-translational modifications (PTMs) in modulating chromatin structure. However, an acutely understudied related feature of chromatin structure is the role of linker histone H1. Previous assumptions of the functional redundancy of the 11 nonallelic H1 variants are contrasted by their strong evolutionary conservation, variability in their potential PTMs, and increased reports of their disparate functions, sub-nuclear localizations and unique expression patterns in different cell types. The commonly accepted notion that histone H1 functions solely in chromatin compaction and transcription repression is now being challenged by work from multiple groups. These studies highlight histone H1 variants as underappreciated facets of chromatin dynamics that function independently in various chromatin-based processes. In this review, we present notable findings involving the individual somatic H1 variants of which there are seven, underscoring their particular contributions to distinctly significant chromatin-related processes.
染色质和表观遗传学领域的重大进展揭示了核心组蛋白、组蛋白变体及其翻译后修饰（PTMs）在调节染色质结构中的重要性。然而，染色质结构中一个研究得很少的相关特征是连接组蛋白 H1 的作用。11 种非等位 H1 变体的功能冗余的先前假设与它们在进化上的强烈保守性、潜在 PTM 的可变性以及在不同细胞类型中功能、亚核定位和独特表达模式的不同报告形成鲜明对比。组蛋白 H1 仅在染色质紧缩和转录抑制中起作用的这一普遍观点正受到多个研究小组的挑战。这些研究强调了组蛋白 H1 变体作为染色质动力学中未被充分认识的方面，它们在各种基于染色质的过程中独立发挥作用。在这篇综述中，我们介绍了涉及七个个体体细胞 H1 变体的显著发现，强调了它们对明显重要的染色质相关过程的特殊贡献。
