title: Deacetylation and methylation at histone H3 lysine 9 (H3K9) coordinate chromosome condensation during cell cycle progression.
abstract: Interphasic chromatin condenses into the chromosomes in order to facilitate the correct segregation of genetic information. It has been previously reported that the phosphorylation and methylation of the N-terminal tail of histone H3 are responsible for chromosome condensation. In this study, we demonstrate that the deacetylation and methylation of histone H3 lysine 9 (H3K9) are required for proper chromosome condensation. We confirmed that H3K9ac levels were reduced, whereas H3K9me3 levels were increased in mitotic cells, via immunofluorescence and Western blot analysis. Nocodazole treatment induced G2/M arrest but co-treatment with TSA, an HDAC inhibitor, delayed cell cycle progression. However, the HMTase inhibitor, AdoX, had no effect on nocodazole-induced G2/M arrest, thereby indicating that sequential modifications of H3K9 are required for proper chromosome condensation. The expression of SUV39H1 and SETDB1, H3K9me3-responsible HMTases, are specifically increased along with H3K9me3 in nocodazole-arrested buoyant cells, which suggests that the increased expression of those proteins is an important step in chromosome condensation. H3K9me3 was highly concentrated in the vertical chromosomal axis during prophase and prometaphase. Collectively, the results of this study indicate that sequential modifications at H3K9 are associated with correct chromosome condensation, and that H3K9me3 may be relevant to the condensation of chromosome length.
authors.affiliation: Medical and Bio-Material Research Center and Department of Biology, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Korea.
authors.forename: Jin-Ah
authors.initials: JA
authors.lastname: Park
authors.forename: Ae-Jin
authors.initials: AJ
authors.lastname: Kim
authors.forename: Yoonsung
authors.initials: Y
authors.lastname: Kang
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Jung
authors.forename: Hyong Kyu
authors.initials: HK
authors.lastname: Kim
authors.forename: Keun-Cheol
authors.initials: KC
authors.lastname: Kim
mesh_terms: D000107:Acetylation; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism; D002877:Chromosomes, Human / Q000737:chemistry / Q000378:metabolism*; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D019877:Hydroxymethyl and Formyl Transferases / Q000378:metabolism*; D008239:Lysine / Q000737:chemistry / Q000378:metabolism*; D008745:Methylation; D015739:Nocodazole / Q000494:pharmacology; D009690:Nucleic Acid Conformation; D011499:Protein Processing, Post-Translational
chemical_list: D002843:Chromatin; D006657:Histones; D019877:Hydroxymethyl and Formyl Transferases; D008239:Lysine; D015739:Nocodazole