title: Aurora-B phosphorylates Histone H3 at serine28 with regard to the mitotic chromosome condensation.
abstract: BACKGROUND
  Histone H3 (H3) phosphorylation plays important roles in mitotic chromosome condensation. We reported that H3 phosphorylation occurs at Ser28, as well as at Ser10 during mitosis, at least in mammals. Aurora B was recently demonstrated to be responsible for Ser10 phosphorylation in S. cerevisiae, C. elegans, Drosophila and Xenopus egg extract.
  
  
  RESULTS
  We compared the distribution of Aurora-B with that of H3 phosphorylation. Aurora-B was primarily localized in the heterochromatin of late G2 phase cells, where only Ser10 phosphorylation was observed. The treatment of such cells with calyculin A induced Ser28 phosphorylation in the Aurora-B-localized area. During prophase to metaphase, Aurora-B was distributed in condensing chromosomes where Ser10 and Ser28 were phosphorylated. Aurora-B can phosphorylate H3-Ser10 and -Ser28 in nucleosomes in vitro. Transfection of a dominant-negative mutant of Aurora-B resulted in a reduction of H3 phosphorylation, not only at Ser10 but also Ser28, during mitosis.
  
  
  CONCLUSIONS
  With regard to mitotic chromosome condensation, Aurora-B directly phosphorylated H3, not only at Ser10 but also at Ser28. The level of Ser28 phosphorylation is diminished to undetectable levels by PP1 phosphatase prior to entry into mitosis.
authors.affiliation: Division of Biochemistry, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya, Aichi464-8681, Japan.
authors.forename: Hidemasa
authors.initials: H
authors.lastname: Goto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yasui
authors.forename: Erich A
authors.initials: EA
authors.lastname: Nigg
authors.forename: Masaki
authors.initials: M
authors.lastname: Inagaki
mesh_terms: D064107:Aurora Kinase B; D064127:Aurora Kinases; D002875:Chromosomes / Q000502:physiology*; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D008938:Mitosis / Q000502:physiology*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012694:Serine
chemical_list: D006657:Histones; D012694:Serine; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases