Estrogen receptor phosphorylation. Hormonal dependence and consequence on specific DNA binding.
We have shown that the 32P-phosphorylation of the nuclear estrogen receptor from human MCF-7 cells or the calf uterus is estrogen-dependent. Within 2 min of estradiol treatment the phosphorylation of the estrogen receptor from MCF-7 cells doubled, and increased 4-fold within 20-40 min of estradiol treatment. Progesterone was ineffective in stimulating the phosphorylation of the estrogen receptor. Phosphoamino acid analysis indicated that the estrogen-stimulated phosphorylation of the human or calf estrogen receptor occurred only on serine residue(s). Phosphotryptic peptide analysis of the human estrogen receptor by two-dimensional peptide mapping or reverse-phase high pressure liquid chromatography revealed that only a single tryptic peptide (site) was phosphorylated. Treatment of the estrogen receptor with potato acid phosphatase resulted in the dephosphorylation of the 32P-labeled estrogen receptor and a decrease of the receptor's affinity for specific DNA sequences. These data suggest that transcriptional activation by the estrogen receptor involves an estrogen-dependent phosphorylation of the receptor resulting in its increased affinity for specific DNA sequences.
Denton
R R
RR
Department of Biophysics, University of Rochester School of Medicine and Dentistry, New York 14642.
Koszewski
N J
NJ
Notides
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AC
D000230:Adenocarcinoma / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000378:metabolism; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004247:DNA / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004958:Estradiol / Q000502:physiology*; D005260:Female; D006801:Humans; D007700:Kinetics; D010449:Peptide Mapping; D010766:Phosphorylation; D011960:Receptors, Estrogen / Q000378:metabolism*; D013379:Substrate Specificity; D014407:Tumor Cells, Cultured; D014599:Uterus / Q000378:metabolism
D011960:Receptors, Estrogen; D004958:Estradiol; D004247:DNA