Somatomedin-C stimulates the phosphorylation of the beta-subunit of its own receptor.

摘要: Phosphorylation of the somatomedin-C receptor was investigated both in intact IM-9 cells and that had been solubilized with Triton X-100. Intact were incubated [32P]H3PO4 for 1 h an additional 5 min absence or presence insulin somatomedin-C. The then subjected to wheat germ agglutinin Sepharose chromatography. extent phosphorylation receptors assessed by immunoprecipitating eluates monoclonal antibodies specific each analyzing immunoprecipitates sodium dodecyl sulfate-polyacrylamide gel electrophoresis. beta-subunits phosphorylated hormone, enhanced hormones. However, hormone more potent than other enhancing its own receptor. beta-subunit also when purified on [gamma-32P]ATP. In this soluble preparation, occurred tyrosyl residues concentrations range 2.5 250 ng/ml, which is consistent affinity. Tyrosyl highly receptor, prepared affinity chromatography followed immunoprecipitation, This indicates responsible kinase activity intrinsic tightly associated it.