Kharbanda S, Saleem A, Datta R, Yuan Z M, Weichselbaum R, Kufe D
Division of Cancer Pharmacology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115.
Cancer Res. 1994 Mar 15;54(6):1412-4.
Eukaryotic cells respond to ionizing radiation exposure with cell cycle arrest. However, little is known about the signaling mechanisms responsible for this effect. The present work has asked whether ionizing radiation exposure is associated with changes in phosphorylation of proteins in HL-60 myeloid leukemia cells. The results demonstrate increased tyrosine phosphorylation of a M(r) 34,000 substrate. This effect was detectable at 1 to 10 min after irradiation and was induced by doses of 50 to 500 cGy. Immunoprecipitation studies further suggest that this substrate is the serine/threonine p34cdc2 protein kinase. Since p34cdc2 is required for entry into mitosis, these findings support the posttranslational modification of a cell cycle regulatory protein in the response to ionizing radiation.
真核细胞对电离辐射暴露的反应是细胞周期停滞。然而，对于导致这种效应的信号传导机制知之甚少。目前的研究探讨了电离辐射暴露是否与HL-60髓系白血病细胞中蛋白质磷酸化的变化有关。结果表明，一种分子量为34,000的底物的酪氨酸磷酸化增加。这种效应在照射后1至10分钟即可检测到，且由50至500 cGy的剂量诱导产生。免疫沉淀研究进一步表明，该底物是丝氨酸/苏氨酸p34cdc2蛋白激酶。由于进入有丝分裂需要p34cdc2，这些发现支持了在对电离辐射的反应中细胞周期调节蛋白的翻译后修饰。
