Journal of Biochemistry Advance Access originally published online on May 23, 2007
Journal of Biochemistry 2007 142(2):145-155; doi:10.1093/jb/mvm118
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© 2007 The Japanese Biochemical Society.
Proteomic Study on X-irradiation-responsive Proteins and Ageing: Search for Responsible Proteins for Radiation Adaptive Response
1Research Team for Functional Genomics; 2Research Team for Molecular Biomarker, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan; 3Analytical & Measuring Instruments Division, Shimadzu Corporation, 1, Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto 604-8511, Japan; and 4Department of Applied Chemistry, Shibaura Institute of Technology, 3-7-5 Toyosu, Kohtoh-ku, Tokyo 135-8548, Japan
*To whom correspondence should be addressed. Tel: +81-3-3964-3241, Fax: +81-3-3579-4776, E-mail: miura{at}center.tmig.or.jp
Received May 2, 2007; Accepted May 13, 2007
| Abstract |
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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-1ß and phospho-ß-actin being altered by 0.1 Gy irradiation; however, ageing did not affect the alteration of phospho-EF-1ß and phospho-ß-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.
Key Words: adaptive response, ageing, oxidative stress, proteomics, radiation
Abbreviations: 2D PAGE, 2-dimensional polyacrylamide gel electrophoresis; IEF, isoelectric focusing; MALDI-TOF, matrix-assisted laser desorption/ionization-time of flight; MS, mass spectrometry; PRDX, peroxiredoxin; EF, elongation factor