title: Expression and radiation-induced phosphorylation of histone H2AX in mammalian cells.
abstract: The mouse histone H2AX (H2AX) has unique C-terminal Ser residues, which are phosphorylated in response to DNA double-strand breaks (DSBs) by ionizing radiation, suggesting that it plays a role in the maintenance of genomic stability. Here, we show that the H2AX protein was detected in most cells in various tissues, and was abundant in the S phase of the cell cycle. Following X-ray irradiation, H2AX was phosphorylated (gamma-H2AX) in the thymus, small intestine and testis. However, H2AX in epithelial cells in the villi of the small intestine were not strongly phosphorylated, even after X-irradiation. Thus, H2AX was expressed in almost all cells. However, the cells that expressed H2AX were not always phosphorylated by X-irradiation, suggesting a different mechanism of kination in those cells.
authors.affiliation: Department of Molecular Genetics, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Kayo
authors.initials: K
authors.lastname: Yoshida
authors.forename: Shu-Hei
authors.initials: SH
authors.lastname: Yoshida
authors.forename: Chikashi
authors.initials: C
authors.lastname: Shimoda
authors.forename: Takashi
authors.initials: T
authors.lastname: Morita
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004249:DNA Damage; D006657:Histones / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D010766:Phosphorylation / Q000528:radiation effects; D011832:Radiation Injuries / Q000235:genetics* / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D006657:Histones; C475961:gamma-H2AX protein, mouse