From the Division of Developmental Biology and.
the Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan.
J Biol Chem. 2019 Feb 8;294(6):1904-1914. doi: 10.1074/jbc.RA118.005550. Epub 2018 Dec 14.
The variant histone H3.3 is incorporated into the genome in a transcription-dependent manner. This histone is thus thought to play a role in epigenetic regulation. However, our understanding of how H3.3 controls gene expression and epigenome landscape has remained incomplete. This is partly because precise localization of H3.3 in the genome has been difficult to decipher particularly for cells To circumvent this difficulty, we generated knockin mice, by homologous recombination, to replace both of the two H3.3 loci ( and ) with the hemagglutinin-tagged H3.3 cDNA cassette, which also contained a GFP gene. We show here that the hemagglutinin-tagged H3.3 and GFP are expressed in the majority of cells in all adult tissues tested. ChIP-seq data, combined with RNA-seq, revealed a striking correlation between the level of transcripts and that of H3.3 accumulation in expressed genes. Finally, we demonstrate that H3.3 deposition is markedly enhanced upon stimulation by interferon on interferon-stimulated genes, highlighting transcription-coupled H3.3 dynamics. Together, these H3.3 knockin mice serve as a useful experimental model to study epigenome regulation in development and in various adult cells .
变体组蛋白 H3.3 以依赖转录的方式被整合到基因组中。因此，人们认为这种组蛋白在表观遗传调控中发挥作用。然而，我们对 H3.3 如何控制基因表达和表观基因组景观的理解仍然不完整。部分原因是 H3.3 在基因组中的精确定位一直难以解读，特别是对于细胞。为了规避这一困难，我们通过同源重组生成了敲入小鼠，用带有绿色荧光蛋白（GFP）基因的带有血凝素标签的 H3.3 cDNA 盒替换了两个 H3.3 基因座（和）。我们在这里表明，在所有测试的成年组织的大多数细胞中，均表达了带有血凝素标签的 H3.3 和 GFP。ChIP-seq 数据与 RNA-seq 相结合，揭示了在表达基因中，转录物的水平与 H3.3 积累之间存在惊人的相关性。最后，我们证明干扰素刺激基因上的干扰素刺激后，H3.3 的沉积明显增强，突出了转录偶联的 H3.3 动力学。总之，这些 H3.3 敲入小鼠可作为研究发育过程中和各种成年细胞中表观基因组调控的有用实验模型。
