We have shown with in vitro experiments that uterus estradiol receptor undergoes dephosphorylation by and endogenous nuclear phosphotyrosine phosphatase and phosphorylation on tyrosine by and endogenous calmodulin-stimulated kinase (Migliaccio, Rotondi and Auricchio: Proc.Natl.Acad.Sci.USA.1984,81,5921). This process regulates the hormone binding activity of the receptor: phosphorylation confers hormone binding to the receptor and dephosphorylaton abolishes this binding. We found that caif uterus estradiol receptor as well rat liver glucocorticoid receptor interact with high affinity and specifity with antiphosphotyrosine antibodies coupled with Sepharose . we used a two step procedure , heparine-sepharose followed by anti-P-tyr-Sepharose to obtain high purified estradiol and glucocorticoid receptors. Dephosphorylation of the estradiol receptor by and endogenous phosphotyrosine phosphatase abolishes both hormone binding and interaction of the receptor with antibodies. This fact suggests that phosphorylation on tyrosine of the estradiol receptor is responsible for the binding of the receptor to antiphosphotyrosine antibodies and consequently, that also in vivo this receptor is phosphorylated on tyrosine. Our experiment also suggest the intriguing possibility that he glucocorticoid receptor is phosphorylated on tyrosine.
Interaction of steroid receptors with monoclonal antiphosphotyrosine antibody.
CASTORIA, Gabriella;MIGLIACCIO, Antimo;DI DOMENICO, Marina;
1986
Abstract
We have shown with in vitro experiments that uterus estradiol receptor undergoes dephosphorylation by and endogenous nuclear phosphotyrosine phosphatase and phosphorylation on tyrosine by and endogenous calmodulin-stimulated kinase (Migliaccio, Rotondi and Auricchio: Proc.Natl.Acad.Sci.USA.1984,81,5921). This process regulates the hormone binding activity of the receptor: phosphorylation confers hormone binding to the receptor and dephosphorylaton abolishes this binding. We found that caif uterus estradiol receptor as well rat liver glucocorticoid receptor interact with high affinity and specifity with antiphosphotyrosine antibodies coupled with Sepharose . we used a two step procedure , heparine-sepharose followed by anti-P-tyr-Sepharose to obtain high purified estradiol and glucocorticoid receptors. Dephosphorylation of the estradiol receptor by and endogenous phosphotyrosine phosphatase abolishes both hormone binding and interaction of the receptor with antibodies. This fact suggests that phosphorylation on tyrosine of the estradiol receptor is responsible for the binding of the receptor to antiphosphotyrosine antibodies and consequently, that also in vivo this receptor is phosphorylated on tyrosine. Our experiment also suggest the intriguing possibility that he glucocorticoid receptor is phosphorylated on tyrosine.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.