Ralston R, Bishop J M
Proc Natl Acad Sci U S A. 1985 Dec;82(23):7845-9. doi: 10.1073/pnas.82.23.7845.
We have observed a modification of the cellular protein kinase pp60c-src, elicited in murine 3T3 fibroblasts by platelet-derived growth factor (PDGF). The modification occurred rapidly after addition of PDGF to the culture medium and was first detected as a reduction in the electrophoretic mobility of a portion of the pp60c-src molecules. A similarly modified form of the viral homologue pp60v-src occurs in vivo in the absence of stimulation by PDGF. The occurrence of modified forms of both pp60c-src and pp60v-src was associated with a novel phosphorylation at tyrosine in the amino-terminal domains of the proteins. The time-course and dose-response for this modification of pp60c-src paralleled PDGF-induced increases in phosphorylation of pp36, a major cellular substrate for several tyrosine-specific protein kinases. In parallel experiments, treatment of cells with PDGF increased the kinase activity of pp60c-src in an immunocomplex assay. These results suggest pp60c-src may play a role in the mitogenic response to PDGF.
我们观察到血小板衍生生长因子（PDGF）在鼠3T3成纤维细胞中引发了细胞蛋白激酶pp60c-src的修饰。在向培养基中添加PDGF后，这种修饰迅速发生，最初检测到的是一部分pp60c-src分子的电泳迁移率降低。在没有PDGF刺激的情况下，病毒同源物pp60v-src在体内也会出现类似修饰的形式。pp60c-src和pp60v-src修饰形式的出现与蛋白质氨基末端结构域中酪氨酸的新磷酸化有关。pp60c-src这种修饰的时间进程和剂量反应与PDGF诱导的pp36磷酸化增加平行，pp36是几种酪氨酸特异性蛋白激酶的主要细胞底物。在平行实验中，用PDGF处理细胞会在免疫复合物测定中增加pp60c-src的激酶活性。这些结果表明，pp60c-src可能在对PDGF的促有丝分裂反应中发挥作用。
