Department of Microbiology and Molecular Genetics, Institute of Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University, Jerusalem, Israel.
Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
Life Sci Alliance. 2022 Aug 18;5(10). doi: 10.26508/lsa.202201433. Print 2022 Oct.
Histone acetylation levels are reduced during mitosis. To study the mitotic regulation of H3K9ac, we used an array of inhibitors targeting specific histone deacetylases. We evaluated the involvement of the targeted enzymes in regulating H3K9ac during all mitotic stages by immunofluorescence and immunoblots. We identified HDAC2, HDAC3, and SIRT1 as modulators of H3K9ac mitotic levels. HDAC2 inhibition increased H3K9ac levels in prophase, whereas HDAC3 or SIRT1 inhibition increased H3K9ac levels in metaphase. Next, we performed ChIP-seq on mitotic-arrested cells following targeted inhibition of these histone deacetylases. We found that both HDAC2 and HDAC3 have a similar impact on H3K9ac, and inhibiting either of these two HDACs substantially increases the levels of this histone acetylation in promoters, enhancers, and insulators. Altogether, our results support a model in which H3K9 deacetylation is a stepwise process-at prophase, HDAC2 modulates most transcription-associated H3K9ac-marked loci, and at metaphase, HDAC3 maintains the reduced acetylation, whereas SIRT1 potentially regulates H3K9ac by impacting HAT activity.
组蛋白乙酰化水平在有丝分裂过程中降低。为了研究 H3K9ac 的有丝分裂调控，我们使用了一系列针对特定组蛋白去乙酰化酶的抑制剂。我们通过免疫荧光和免疫印迹评估了靶向酶在所有有丝分裂阶段调节 H3K9ac 的参与情况。我们确定了 HDAC2、HDAC3 和 SIRT1 是 H3K9ac 有丝分裂水平的调节剂。HDAC2 抑制增加了前期的 H3K9ac 水平，而 HDAC3 或 SIRT1 抑制增加了中期的 H3K9ac 水平。接下来，我们在靶向抑制这些组蛋白去乙酰化酶后，对有丝分裂期被捕获的细胞进行了 ChIP-seq 实验。我们发现 HDAC2 和 HDAC3 对 H3K9ac 有相似的影响，抑制这两种 HDAC 中的任何一种都会显著增加启动子、增强子和绝缘子中这种组蛋白乙酰化的水平。总之，我们的结果支持了这样一种模型，即 H3K9 去乙酰化是一个逐步的过程——在前期，HDAC2 调节大多数与转录相关的 H3K9ac 标记基因座，而在中期，HDAC3 维持降低的乙酰化水平，而 SIRT1 可能通过影响 HAT 活性来调节 H3K9ac。
