Ferris D K, Willet-Brown J, Martensen T, Farrar W L
Program Resources Inc., Frederick Cancer Research Facility, MD 21701-1013.
Biochem Biophys Res Commun. 1988 Aug 15;154(3):991-6. doi: 10.1016/0006-291x(88)90237-9.
Interleukin 3 stimulates the proliferation of FDC-P1, a murine myeloid cell line, however the biochemical events subsequent to binding of IL3 have only recently begun to be investigated. We have previously described the activation of protein kinase C (PK-C) and serine/threonine phosphorylation of a 68 kd protein following IL3 treatment of FDC-P1 cells. Here we have used an anti-phosphotyrosine antibody to purify proteins containing phosphotyrosine following IL3 administration to FDC-P1 cells. We find that tyrosine phosphorylation of two proteins of 50 (pp50) and 70 (pp70) kilodaltons occurs rapidly following IL3 treatment. In addition to phosphotyrosine both proteins also contained phosphoserine. Together with previous evidence these results suggest that coactivation of serine/threonine and tyrosine kinase activities which target unique proteins may be an important element in IL3 signal transduction.
白细胞介素3可刺激小鼠髓样细胞系FDC-P1的增殖，然而，白细胞介素3结合后的生化事件直到最近才开始被研究。我们之前曾描述过，用白细胞介素3处理FDC-P1细胞后，蛋白激酶C（PK-C）的激活以及一种68千道尔顿蛋白的丝氨酸/苏氨酸磷酸化。在此，我们使用抗磷酸酪氨酸抗体，在向FDC-P1细胞施用白细胞介素3后纯化含磷酸酪氨酸的蛋白。我们发现，用白细胞介素3处理后，两种分别为50千道尔顿（pp50）和70千道尔顿（pp70）的蛋白会迅速发生酪氨酸磷酸化。除磷酸酪氨酸外，这两种蛋白还含有磷酸丝氨酸。结合之前的证据，这些结果表明，靶向独特蛋白的丝氨酸/苏氨酸激酶和酪氨酸激酶活性的共同激活可能是白细胞介素3信号转导中的一个重要因素。
