title: Reconstitution of epidermal growth factor receptor transmodulation by platelet-derived growth factor in Chinese hamster ovary cells.
abstract: Platelet-derived growth factor (PDGF) causes an acute decrease in the high affinity binding of epidermal growth factor (EGF) to cell surface receptors and an increase in the phosphorylation state of the EGF receptor at threonine654. The hypothesis that PDGF action to regulate the EGF receptor is mediated by the activation of protein kinase C and the subsequent phosphorylation of EGF receptor threonine654 was tested. The human receptors for PDGF and EGF were expressed in Chinese hamster ovary cells that lack expression of endogenous receptors for these growth factors. The heterologous regulation of the EGF receptor by PDGF was reconstituted in cells expressing [Thr654]EGF receptors or [Ala654]EGF receptors. PDGF action was also observed in phorbol ester down-regulated cells that lack detectable protein kinase C activity. Together these data indicate that neither protein kinase C nor the phosphorylation of EGF receptor threonine654 is required for the regulation of the apparent affinity of the EGF receptor by PDGF.
authors.affiliation: Department of Biochemistry, University of Massachusetts Medical School, Worcester 01655.
authors.forename: J L
authors.initials: JL
authors.lastname: Countaway
authors.forename: N
authors.initials: N
authors.lastname: Gironès
authors.forename: R J
authors.initials: RJ
authors.lastname: Davis
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000235:genetics; D004261:DNA Replication; D066246:ErbB Receptors / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D007700:Kinetics; D010053:Ovary; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
chemical_list: D010982:Platelet-Derived Growth Factor; D011956:Receptors, Cell Surface; D004247:DNA; D066246:ErbB Receptors; D017479:Receptors, Platelet-Derived Growth Factor; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate