Penta K, Sawyer S T
Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2287, USA.
J Biol Chem. 1995 Dec 29;270(52):31282-7. doi: 10.1074/jbc.270.52.31282.
We have investigated whether Signal Transducing and Activators of Transcription (STAT) proteins become activated following the binding of erythropoietin (EPO) to immature erythroid cells from the spleens of mice infected with the anemia strain of Friend virus. STAT1 and STAT5 proteins are phosphorylated and translocated to the nucleus in EPO-treated cells. STAT1 and STAT5 DNA binding activities were also activated in an EPO-dependent manner. The presence of these STAT proteins in the DNA binding complex was confirmed by Western blot analysis of the proteins bound to the DNA element in the gel mobility shift assays. This EPO-dependent activation of STAT proteins was maximum within 10 min of exposure of the cells to 10 units of EPO/ml, the concentration of EPO required for maximum STAT activation. The magnitude of the EPO-dependent STAT5 activation appeared to be greater than the EPO-dependent activation of STAT1. The significance of STAT protein activation in EPO signal transduction is discussed.
我们研究了在促红细胞生成素（EPO）与感染了贫血型Friend病毒的小鼠脾脏中的未成熟红细胞结合后，信号转导及转录激活因子（STAT）蛋白是否会被激活。在经EPO处理的细胞中，STAT1和STAT5蛋白发生磷酸化并转位至细胞核。STAT1和STAT5的DNA结合活性也以EPO依赖的方式被激活。通过对凝胶迁移率变动分析中与DNA元件结合的蛋白质进行蛋白质免疫印迹分析，证实了这些STAT蛋白存在于DNA结合复合物中。细胞暴露于10单位EPO/ml（最大STAT激活所需的EPO浓度）后10分钟内，STAT蛋白的这种EPO依赖性激活达到最大值。EPO依赖性STAT5激活的程度似乎大于EPO依赖性STAT1激活的程度。文中讨论了STAT蛋白激活在EPO信号转导中的意义。
