title: Role of histone modifications in marking and activating genes through mitosis.
abstract: The global inhibition of transcription at the mitotic phase of the cell cycle occurs together with the general displacement of transcription factors from the mitotic chromatin. Nevertheless, the DNase- and potassium permanganate-hypersensitive sites are maintained on potentially active promoters during mitosis, helping to mark active genes at this stage of the cell cycle. Our study focuses on the role of histone acetylation and H3 (Lys-4) methylation in the maintenance of the competency of these active genes during mitosis. To this end we have analyzed histone modifications across the promoters and coding regions of constitutively active, inducible, and inactive genes in mitotic arrested cells. Our results show that basal histone modifications are maintained during mitosis at promoters and coding regions of the active and inducible RNA polymerase II-transcribed genes. In addition we have demonstrated that, together with H3 acetylation and H3 (Lys-4) methylation, H4 (Lys-12) acetylation at the coding regions contributes to the formation of a stable mark on active genes at this stage of the cell cycle. Finally, analysis of cyclin B1 gene activation during mitosis revealed that the former occurs with a strong increase of H3 (Lys-4) trimethylation but not H3 or H4 acetylation, suggesting that histone methyltransferases are active during this stage. These data demonstrate a critical role of histone acetylation and H3 (Lys-4) methylation during mitosis in marking and activating genes during the mitotic stage of the cell cycle.
authors.affiliation: Instituto de Biología Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, Parc Cientific de Barcelona, Josep Samitier 1-5, 08028 Barcelona, Spain.
authors.forename: Ester
authors.initials: E
authors.lastname: Valls
authors.forename: Sara
authors.initials: S
authors.lastname: Sánchez-Molina
authors.forename: Marian A
authors.initials: MA
authors.lastname: Martínez-Balbás
mesh_terms: D000107:Acetylation; D002453:Cell Cycle; D002467:Cell Nucleus / Q000378:metabolism; D048750:Cell Nucleus Division; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation; D006367:HeLa Cells; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism; D006657:Histones / Q000737:chemistry*; D006801:Humans; D015151:Immunoblotting; D007399:Interphase; D008239:Lysine / Q000737:chemistry; D008745:Methylation; D008938:Mitosis; D009707:Nucleosomes / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011496:Protein Methyltransferases; D011499:Protein Processing, Post-Translational; D012319:RNA Polymerase II / Q000378:metabolism; D013696:Temperature; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: C534699:CCNB1 protein, human; D002843:Chromatin; D019926:Cyclin B; D056744:Cyclin B1; D006657:Histones; D009707:Nucleosomes; D000076983:Histone Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D012319:RNA Polymerase II; D008239:Lysine