Anti-(insulin receptor) monoclonal antibody-stimulated tyrosine phosphorylation in cells transfected with human insulin receptor cDNA.

摘要: The effects of insulin and anti-(insulin receptor) monoclonal antibodies on tyrosine phosphorylation were investigated in fibroblasts transfected with human receptor cDNA (NIH 3T3HIR3.5 cells) using anti-phosphotyrosine immunoblotting. Insulin increased levels two major proteins molecular mass 97 kDa (pp97, assumed to be the beta-subunit) 185 (pp185). Insulin-mimetic anti-receptor also stimulated both pp97 pp185. observation antibody-stimulated phosphorylation, as detected by immunoblotting, is contrast previous data which failed show autophosphorylation NIH cells labelled [32P]P1. effect was maximal within 1 min, but response antibody apparent only after a lag 1-2 min rose steadily over 20 min. absolute level pp185 about 20% maximum induced equivalent concentrations insulin, even at sufficient for full occupancy receptors. Another insulin-mimetic agent, wheat-germ agglutinin, kinetics similar those produced antibody. It suggested that relatively slow responses agents may function dependence cross-linking. These are consistent role kinase activity mechanism action antibodies.