title: Proteomic study on X-irradiation-responsive proteins and ageing: search for responsible proteins for radiation adaptive response.
abstract: We investigated high- or low-dose irradiation-responsive proteins using proteomics on two-dimensional (2D) PAGE, and the effects of ageing on cell responses to radiation in variously aged rat astrocytes. After 5 Gy irradiation, the relative abundance of peroxiredoxin 2, an antioxidant enzyme, and latexin, an inhibitor of carboxypeptidase, increased. The induction of these proteins was suppressed by ageing, suggesting that the response to high-dose radiation decreased with ageing. The relative abundance of elongation factor 2 (EF-2) fragment increased 3 h and reduced 24 h after 0.1 Gy irradiation. Temporal enhancement of the EF-2 fragment due to low-dose irradiation was suppressed by ageing. Since radiation adaptive response in cultured astrocytes was observed 3 h but not 24 h after 0.1 Gy irradiation and suppressed by ageing as previously reported, alteration of the EF-2 fragment corresponded to the radiation adaptive response. We also examined phospho-protein profiles, resulting in the relative abundance of phospho-EF-1beta and phospho-beta-actin being altered by 0.1 Gy irradiation; however, ageing did not affect the alteration of phospho-EF-1beta and phospho-beta-actin, unlike the EF-2 fragment. The results suggested that the EF-2 fragment was a possible candidate for the protein responsible for the radiation adaptive response in cultured astrocytes.
authors.affiliation: Research Team for Functional Genomics, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan. miura@center.tmig.or.jp
authors.forename: Yuri
authors.initials: Y
authors.lastname: Miura
authors.forename: Mayumi
authors.initials: M
authors.lastname: Kano
authors.forename: Masaki
authors.initials: M
authors.lastname: Yamada
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishine
authors.forename: Shiro
authors.initials: S
authors.lastname: Urano
authors.forename: Shozo
authors.initials: S
authors.lastname: Suzuki
authors.forename: Tamao
authors.initials: T
authors.lastname: Endo
authors.forename: Tosifusa
authors.initials: T
authors.lastname: Toda
mesh_terms: D000064:Acclimatization; D000595:Amino Acid Sequence; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D008969:Molecular Sequence Data; D020652:Peptide Elongation Factor 2 / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000032:analysis; D010766:Phosphorylation; D040901:Proteomics; D012333:RNA, Messenger / Q000378:metabolism; D011836:Radiation Tolerance; D051381:Rats; D017208:Rats, Wistar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D020652:Peptide Elongation Factor 2; D010750:Phosphoproteins; D012333:RNA, Messenger