Rachael E. Matthews, Joshua Miguel C. Danac, Emily L. Naden, Laura E. Farleigh Smith, Sri Lestari, Akhila Gungi, Alex Appert, Toby Buttress, Ankit Verma, Oliver Sinclair, Faye Chong, John Suberu, Robin Antrobus, Boyan Bonev, Mark A. Dawson, Adam J. Reid, Richard T. Timms, Julie Ahringer, Iva A. Tchasovnikarova
{"title":"CRAMP1 drives linker histone expression to enable Polycomb repression","authors":"Rachael E. Matthews, Joshua Miguel C. Danac, Emily L. Naden, Laura E. Farleigh Smith, Sri Lestari, Akhila Gungi, Alex Appert, Toby Buttress, Ankit Verma, Oliver Sinclair, Faye Chong, John Suberu, Robin Antrobus, Boyan Bonev, Mark A. Dawson, Adam J. Reid, Richard T. Timms, Julie Ahringer, Iva A. Tchasovnikarova","doi":"10.1016/j.molcel.2025.05.031","DOIUrl":null,"url":null,"abstract":"In contrast to the well-understood role of core histones in DNA packaging, the function of the linker histone (H1) remains enigmatic. Challenging the prevailing view that linker histones are a general feature of heterochromatin, here we show a critical requirement for H1 in Polycomb repressive complex 2 (PRC2) function. A CRISPR-Cas9 genetic screen using a fluorescent PRC2 reporter identified an essential role for the poorly characterized gene <em>CRAMP1</em> in PRC2-mediated repression. CRAMP1 localizes to the promoters of expressed H1 genes and positively regulates their transcription. CRAMP1 ablation simultaneously depletes all linker histones, which results in selective decompaction of H3K27me3-marked loci and derepression of PRC2 target genes without concomitant loss of PRC2 occupancy or enzymatic activity. Strikingly, we find that linker histones preferentially localize to genomic loci marked by H3K27me3 across diverse cell types and organisms. Altogether, these data demonstrate a prominent role for linker histones in epigenetic repression by PRC2.","PeriodicalId":18950,"journal":{"name":"Molecular Cell","volume":"1 1","pages":""},"PeriodicalIF":14.5000,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Cell","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1016/j.molcel.2025.05.031","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
In contrast to the well-understood role of core histones in DNA packaging, the function of the linker histone (H1) remains enigmatic. Challenging the prevailing view that linker histones are a general feature of heterochromatin, here we show a critical requirement for H1 in Polycomb repressive complex 2 (PRC2) function. A CRISPR-Cas9 genetic screen using a fluorescent PRC2 reporter identified an essential role for the poorly characterized gene CRAMP1 in PRC2-mediated repression. CRAMP1 localizes to the promoters of expressed H1 genes and positively regulates their transcription. CRAMP1 ablation simultaneously depletes all linker histones, which results in selective decompaction of H3K27me3-marked loci and derepression of PRC2 target genes without concomitant loss of PRC2 occupancy or enzymatic activity. Strikingly, we find that linker histones preferentially localize to genomic loci marked by H3K27me3 across diverse cell types and organisms. Altogether, these data demonstrate a prominent role for linker histones in epigenetic repression by PRC2.
期刊介绍:
Molecular Cell is a companion to Cell, the leading journal of biology and the highest-impact journal in the world. Launched in December 1997 and published monthly. Molecular Cell is dedicated to publishing cutting-edge research in molecular biology, focusing on fundamental cellular processes. The journal encompasses a wide range of topics, including DNA replication, recombination, and repair; Chromatin biology and genome organization; Transcription; RNA processing and decay; Non-coding RNA function; Translation; Protein folding, modification, and quality control; Signal transduction pathways; Cell cycle and checkpoints; Cell death; Autophagy; Metabolism.