小柯机器人

切换到桌面版
组蛋白编辑阐明哺乳动物中H3K27甲基化和乙酰化的功能作用
2022-06-11 14:50
来源：小柯机器人

丹麦哥本哈根大学Kristian Helin研究团队利用组蛋白编辑阐明哺乳动物中H3K27甲基化和乙酰化的功能作用。2022年6月6日，《自然—遗传学》杂志在线发表了这项成果。

研究人员在小鼠胚胎干细胞（mESC）中使用CRISPR碱基编辑来解析了组蛋白H3第27位赖氨酸（H3K27）的调节作用，这是Polycomb repressive complex 2（PRC2）介导的甲基化和CBP/EP300介导的乙酰化的底物。通过产生泛H3K27R（pK27R）突变体mESC，其中H3.1、H3.2和H3.3的所有28个等位基因都发生了突变，研究人员证明基因的转录模式和分化与PRC2缺失突变体相似。此外，H3K27乙酰化对于与H3K27甲基化丧失有关的基因去抑制，或在细胞命运过渡到外胚层样细胞（EpiLC）期间基因的从头激活并不重要。
 
总之，这些研究结果表明，H3K27是中胚层细胞中PRC2的一个重要底物，而除了H3K27乙酰化外，其他翻译后修饰（PTM）也可能参与介导CBP/EP300功能。该工作证明了大规模多拷贝基因编辑在哺乳动物细胞中审视组蛋白PTM功能的可行性。
 
据了解，组蛋白的PTM与特定的染色质和基因表达状态有关。尽管对黑腹果蝇的研究揭示了染色质修饰酶与其组蛋白底物之间的表型关联，但对哺乳动物模型的可比性研究还不存在。
 
附：英文原文
 
Title: Histone editing elucidates the functional roles of H3K27 methylation and acetylation in mammals

Author: Sankar, Aditya, Mohammad, Faizaan, Sundaramurthy, Arun Kumar, Wang, Hua, Lerdrup, Mads, Tatar, Tulin, Helin, Kristian

Issue&Volume: 2022-06-06

Abstract: Posttranslational modifications of histones (PTMs) are associated with specific chromatin and gene expression states1,2. Although studies in Drosophila melanogaster have revealed phenotypic associations between chromatin-modifying enzymes and their histone substrates, comparable studies in mammalian models do not exist3,4,5. Here, we use CRISPR base editing in mouse embryonic stem cells (mESCs) to address the regulatory role of lysine 27 of histone H3 (H3K27), a substrate for Polycomb repressive complex 2 (PRC2)-mediated methylation and CBP/EP300-mediated acetylation6,7. By generating pan-H3K27R (pK27R) mutant mESCs, where all 28 alleles of H3.1, H3.2 and H3.3 have been mutated, we demonstrate similarity in transcription patterns of genes and differentiation to PRC2-null mutants. Moreover, H3K27 acetylation is not essential for gene derepression linked to loss of H3K27 methylation, or de novo activation of genes during cell-fate transition to epiblast-like cells (EpiLCs). In conclusion, our results show that H3K27 is an essential substrate for PRC2 in mESCs, whereas other PTMs in addition to H3K27 acetylation are likely involved in mediating CBP/EP300 function. Our work demonstrates the feasibility of large-scale multicopy gene editing to interrogate histone PTM function in mammalian cells.

DOI: 10.1038/s41588-022-01091-2

Source: https://www.nature.com/articles/s41588-022-01091-2

Nature Genetics：《自然—遗传学》，创刊于1992年。隶属于施普林格·自然出版集团，最新IF：41.307
官方网址：https://www.nature.com/ng/
投稿链接：https://mts-ng.nature.com/cgi-bin/main.plex


本期文章：《自然—遗传学》：Online/在线发表

分享到:

0