Journal of Biochemistry Advance Access published online on May 23, 2007
Journal of Biochemistry, doi:10.1093/jb/mvm118
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© 2007 The Japanese Biochemical Society
Proteomic Study on X-Irradiation-Responsive Proteins and Aging: 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
4Department of Applied Chemistry, Shibaura Institute of Technology, 3-7-5 Toyosu, Kohtoh-ku, Tokyo 135-8548, Japan
Address correspondence to: Yuri Miura: Research Team for Functional Genomics, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan. 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 (2-D) PAGE, and the effects of aging 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 aging, suggesting that the response to high-dose radiation decreased with aging. 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 aging. Since radiation adaptive response in cultured astrocytes was observed 3 h but not 24 h after 0.1 Gy-irradiation and suppressed by aging 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, aging 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, aging, oxidative stress, proteomics, radiation