title: Immunodetection of the ligand-activated receptor for epidermal growth factor.
abstract: Many receptors for cellular growth factors are known to be protein tyrosine kinases which become activated upon ligand binding at their extracellular domain. We describe here a method to detect the activation state of Epidermal Growth Factor receptor (EGFr) with a monoclonal antibody (mAb74). This antibody was found to preferentially recognize the ligand-activated EGFr as detected by immunoprecipitation, Western blotting and immunocytochemical techniques. mAb74 did not recognize other tyrosine-phosphorylated proteins and was not inhibited by phosphotyrosine, suggesting that it is recognizing an epitope specific for the ligand-activated EGF receptor. The reactivity of mAb74 towards EGFr was closely correlated with the EGF-dependent tyrosine phosphorylation of endogenous substrates. This antibody allows one to detect the activated EGF receptor in vitro or in vivo even in a complex mixture of other tyrosine kinases and substrates.
authors.affiliation: Department of Biochemistry, University of Kentucky, Lexington 40536-0093.
authors.forename: R
authors.initials: R
authors.lastname: Campos-González
authors.forename: J R
authors.initials: JR
authors.lastname: Glenney
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D002460:Cell Line; D004815:Epidermal Growth Factor / Q000494:pharmacology; D000939:Epitopes; D066246:ErbB Receptors / Q000276:immunology / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D010766:Phosphorylation; D019000:Phosphotyrosine; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D019000:Phosphotyrosine; D014443:Tyrosine; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases