Characterization of epidermal growth factor receptor in a rat thyroid cell line, FRTL-5.
A rat thyroid cell line FRTL-5 showed no significant binding of epidermal growth factor(EGF) either in the presence or absence of thyrotropin(TSH). Conditioned medium from FRTL-5 did not inhibit the specific binding of [125I]EGF to HeLa cell which has EGF receptors (EGF-R). Two bands of 170KD and 80KD obtained by immunoprecipitation with solubilized FRTL-5 and anti-EGF-R monoclonal antibody indicated autophosphorylation activity. The activity was enhanced by several thyroid cell growth factors including TSH. dibutyryl-cAMP(db-cAMP), insulin like growth factor I(IGF-I). Interleukin 1 beta (IL-1 beta) and phorbol ester. EGF alone enhanced the autophosphorylation activity. These data indicate that FRTL-5 possesses unique EGF-R with low affinity to EGF and that the tyrosine kinase of the receptor is activated during cell proliferation.
Department of Laboratory Medicine, Kyoto University School of Medicine, Japan.
H
H
Sugawa
M
M
Beniko
H
H
Imura
T
T
Mori
D000818:Animals; D000911:Antibodies, Monoclonal; D003994:Bucladesine / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002478:Cells, Cultured; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D010766:Phosphorylation; D011233:Precipitin Tests; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013972:Thyrotropin / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D007375:Interleukin-1; D004815:Epidermal Growth Factor; D003994:Bucladesine; D007334:Insulin-Like Growth Factor I; D013972:Thyrotropin; D066246:ErbB Receptors; D013755:Tetradecanoylphorbol Acetate