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.

中文翻译：

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缺失的链接器：H1 变体特定功能的新兴趋势

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 (PTM) 在调节染色质结构中的重要性。然而，染色质结构的一个尚未充分研究的相关特征是接头组蛋白 H1 的作用。先前对 11 个非等位基因 H1 变体功能冗余的假设与它们强大的进化保守性、潜在 PTM 的可变性以及不同细胞类型中不同功能、亚核定位和独特表达模式的报告增加形成鲜明对比。普遍接受的观点，即组蛋白 H1 仅在染色质压缩和转录抑制中起作用，现在正受到来自多个小组的工作的挑战。这些研究强调组蛋白 H1 变体是染色质动力学中未被充分认识的方面，这些方面在各种基于染色质的过程中独立发挥作用。在这篇综述中，我们提出了涉及个体体细胞 H1 变体的显着发现，其中有七个，强调了它们对明显重要的染色质相关过程的特殊贡献。