Lu Jun, Suzuki Toshikazu, Satoh Mamoru, Chen Shiping, Tomonaga Takeshi, Nomura Fumio, Suzuki Nobuo
Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8670, Japan.
Biochem Biophys Res Commun. 2008 May 9;369(3):948-52. doi: 10.1016/j.bbrc.2008.02.122. Epub 2008 Mar 5.
To find novel proteins involved in radio-resistance of human cells, we searched for nuclear proteins, whose expression levels alter after X-ray irradiation in HeLa cells, using agarose fluorescent two-dimensional differential gel electrophoresis following mass spectrometry. We identified 6 proteins, whose levels were increased in nuclei 24h after irradiation at 5Gy, including aldolase A. Nuclear aldolase A levels increased twofold after the irradiation, however, total aldolase A levels did not change. When the expression of aldolase A was suppressed by its specific siRNA, sensitization of the suppressed cells to X-ray-induced cell death was observed. In addition, UV(r)-1 cells with higher aldolase A expression exhibited lower sensitivity to X-ray-induced cell death than the parental RSa cells with lower aldolase A expression. These results suggest that aldolase A may play a role in the radio-response of human cells, probably in nuclei, in addition to its glycolytic role in the cytosol.
