Inhibition of the specific DNA binding activity of the dioxin receptor by phosphatase treatment.

摘要: The dioxin receptor stimulates transcription of the cytochrome P-450IA1 gene in response to dioxin. Exposure intracellular leads a rapid conversion from latent form DNA binding species which specifically recognizes dioxin-responsive positive control elements vitro. In this report, we show that treatment vivo or vitro ligand-activated with potato acid phosphatase significantly reduced abolished its specific activity. This effect was inhibited presence sodium phosphate. experiments, glucocorticoid not inactivated by treatment. Moreover, did induce any detectable degradation covalently labeled receptor, arguing against protease contamination as cause for inactivation. Finally, phosphatase-inactivated exhibited bona fide levels ligand Taken together, these data suggest phosphorylation may regulate activity ligand-occupied receptor.