title: Transforming growth factor-alpha binds to the epidermal growth factor receptor in gastric mucosa.
abstract: The ability of transforming growth factor-alpha (TGF-alpha) to interact with the gastric mucosal epidermal growth factor (EGF) receptor was investigated using a mucosal membrane preparation. TGF-alpha inhibited specific binding of [125I]EGF to its receptor, but the IC50 for TGF-alpha was at least 100 fold greater than that observed for unlabeled EGF. Cross-linking studies revealed no attachment of [125I]TGF-alpha to EGF-receptor size components, and the unlabeled TGF-alpha was only weakly effective in inhibiting cross-linking of [125I]EGF to the 170 kDa receptor. However, when the cytosolic fraction was reconstituted with the membrane preparation, an enhancement in binding of [125I]TGF-alpha to the EGF receptor occurred in a manner dependent on the concentration of cytosolic protein. Hence the binding characteristics of TGF-alpha to the EGF receptor in gastric mucosa are different from those for EGF.
authors.affiliation: Research Center, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark 07103-2425.
authors.forename: W J
authors.initials: WJ
authors.lastname: Bielanski
authors.forename: J P
authors.initials: JP
authors.lastname: Keogh
authors.forename: S L
authors.initials: SL
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: S J
authors.initials: SJ
authors.lastname: Konturek
authors.forename: A
authors.initials: A
authors.lastname: Slomiany
authors.forename: B L
authors.initials: BL
authors.lastname: Slomiany
mesh_terms: D000818:Animals; D001667:Binding, Competitive / Q000502:physiology; D003432:Cross-Linking Reagents; D003600:Cytosol / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism*; D007457:Iodine Radioisotopes; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D016211:Transforming Growth Factor alpha / Q000378:metabolism*
chemical_list: D003432:Cross-Linking Reagents; D007457:Iodine Radioisotopes; D016211:Transforming Growth Factor alpha; D066246:ErbB Receptors