Human Insulin-like Growth Factor I Receptor Expressed on Chinese Hamster Ovary Cell Is Functional in Mediating Hormone-Stimulated Receptor Kinase Activity and Glycogen Synthesis

Abstract

Stable transfectants in Chinese hamster ovary cells that express the protein encoded by human insulin-like growth factor I (IGF-I) receptor cDNA (CHO. IGFIR cells) were tested for the stimulatory effect of IGF-I on poly (glu-tyr) phosphorylation and glycogen synthesis. Using ³²P-ATP, IGF-I stimulated the incorporation of ³²P into poly (gly-tyr) in a dose-dependent manner. IGF-I also stimulated glycogen synthesis in this cell line, while much less stimulation was observed in parental CHO cells. These results indicate that the human IGF-I receptor on this cell line is functional and thus likely to be a useful tool in studying the role of IGF-I receptor.