Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
Curr Opin Plant Biol. 2021 Jun;61:101991. doi: 10.1016/j.pbi.2020.101991. Epub 2021 Jan 9.
The dynamic properties of the nucleosome are central to genomic activity. Variants of the core histones that form the nucleosome play a pivotal role in modulating nucleosome structure and function. Despite often small differences in sequence, histone variants display remarkable diversity in genomic deposition and post-translational modification. Here, we summarize the roles played by histone variants in the establishment, maintenance and reprogramming of plant chromatin landscapes, with a focus on histone H3 variants. Deposition of replicative H3.1 during DNA replication controls epigenetic inheritance, while local replacement of H3.1 with H3.3 marks cells undergoing terminal differentiation. Deposition of specialized H3 variants in specific cell types is emerging as a novel mechanism of selective epigenetic reprogramming during the plant life cycle.
核小体的动态特性对基因组的活性至关重要。构成核小体的核心组蛋白的变体在调节核小体结构和功能方面起着关键作用。尽管在序列上通常只有微小的差异，但组蛋白变体在基因组的沉积和翻译后修饰方面表现出显著的多样性。在这里，我们总结了组蛋白变体在建立、维持和重编程植物染色质景观方面所扮演的角色，重点是组蛋白 H3 变体。在 DNA 复制过程中复制性 H3.1 的沉积控制着表观遗传的遗传，而 H3.1 被 H3.3 局部取代则标记着正在进行终端分化的细胞。在植物生命周期中，专门的 H3 变体在特定细胞类型中的沉积正成为一种新的选择性表观遗传重编程机制。
