title: DNA methylation promotes Aurora-B-driven phosphorylation of histone H3 in chromosomal subdomains.
abstract: Confinement of enzymatic reactions to nuclear and chromosomal subdomains regulates functional organization of the nucleus. Aurora-B kinase regulates cell-cycle-dependent phosphorylation of chromosomal substrates through sequential localization to a series of sites on chromosomes and the mitotic spindle. In G2 nuclei, Aurora-B recruitment to heterochromatin restricts histone H3S10 phosphorylation to a domain around centromeres (pericentromeres). However, no intrinsic chromosomal determinants have been implicated in Aurora-B recruitment to interphase pericentromeres. Using cyclin B1 as a cell-cycle marker, we found that the great majority of nuclei exhibiting H3S10 phosphorylated foci were positive for cyclin B1, thus revealing that H3S10 phosphorylation arises at pericentromeres during late S phase and persists in G2. By immunofluorescent in situ hybridization, Aurora-B and H3S10 phosphorylated foci were found more frequently at larger pericentromeres than at smaller ones, revealing a preferential phosphorylation of pericentromeres, exhibiting a high density of methyl cytosines. Disruption of DNA methylation inhibited pericentromeric Aurora-B targeting and H3S10 phosphorylation in G2 nuclei, thus demonstrating the role of DNA methylation in Aurora-B targeting to pericentromeres. These results favour the idea that DNA methylation maintains a local environment essential for regulating the functional properties of sub-chromosomal domains during S-G2 progression.
authors.affiliation: The Scripps Research Institute, Department of Cell Biology, CB163, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA. kmonier@ens-lyon.fr
authors.forename: Karine
authors.initials: K
authors.lastname: Monier
authors.forename: Sandrine
authors.initials: S
authors.lastname: Mouradian
authors.forename: Kevin F
authors.initials: KF
authors.lastname: Sullivan
mesh_terms: D064107:Aurora Kinase B; D064127:Aurora Kinases; D001374:Azacitidine / Q000494:pharmacology; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology; D002503:Centromere / Q000201:enzymology*; D002875:Chromosomes / Q000737:chemistry / Q000201:enzymology*; D019175:DNA Methylation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016195:G2 Phase / Q000502:physiology; D006657:Histones / Q000378:metabolism*; D006801:Humans; D009474:Neurons / Q000166:cytology; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D016196:S Phase / Q000502:physiology; D013234:Stem Cells / Q000166:cytology
chemical_list: D004791:Enzyme Inhibitors; D006657:Histones; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D001374:Azacitidine