4a7j | pdb_00004a7j
Symmetric Dimethylation of H3 Arginine 2 is a Novel Histone Mark that Supports Euchromatin Maintenance
Structural highlights
Function[WDR5_HUMAN] Contributes to histone modification. May position the N-terminus of histone H3 for efficient trimethylation at 'Lys-4'. As part of the MLL1/MLL complex it is involved in methylation and dimethylation at 'Lys-4' of histone H3. H3 'Lys-4' methylation represents a specific tag for epigenetic transcriptional activation. As part of the NSL complex it may be involved in acetylation of nucleosomal histone H4 on several lysine residues. May regulate osteoblasts differentiation.[1] [2] [3] [4] [5] [H31T_HUMAN] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. Publication Abstract from PubMedThe asymmetric dimethylation of histone H3 arginine 2 (H3R2me2a) acts as a repressive mark that antagonizes trimethylation of H3 lysine 4. Here we report that H3R2 is also symmetrically dimethylated (H3R2me2s) by PRMT5 and PRMT7 and present in euchromatic regions. Profiling of H3-tail interactors by SILAC MS revealed that H3R2me2s excludes binding of RBBP7, a central component of co-repressor complexes Sin3a, NURD and PRC2. Conversely H3R2me2s enhances binding of WDR5, a common component of the coactivator complexes MLL, SET1A, SET1B, NLS1 and ATAC. The interaction of histone H3 with WDR5 distinguishes H3R2me2s from H3R2me2a, which impedes the recruitment of WDR5 to chromatin. The crystallographic structure of WDR5 and the H3R2me2s peptide elucidates the molecular determinants of this high affinity interaction. Our findings identify H3R2me2s as a previously unknown mark that keeps genes poised in euchromatin for transcriptional activation upon cell-cycle withdrawal and differentiation in human cells. Symmetric dimethylation of H3R2 is a newly identified histone mark that supports euchromatin maintenance.,Migliori V, Muller J, Phalke S, Low D, Bezzi M, Mok WC, Sahu SK, Gunaratne J, Capasso P, Bassi C, Cecatiello V, De Marco A, Blackstock W, Kuznetsov V, Amati B, Mapelli M, Guccione E Nat Struct Mol Biol. 2012 Jan 8;19(2):136-44. doi: 10.1038/nsmb.2209. PMID:22231400[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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