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Environmental estrogens induce transcriptionally active estrogen receptor dimers in yeast: activity potentiated by the coactivator RIP140.

Sheeler CQ, Dudley MW, Khan SA - Environ. Health Perspect. (2000)

Bottom Line: Incubating yeast in the presence of increasing concentrations of estradiol and OP (1 microM) or BPA (1 microM) neither blocked nor altered the effect of estradiol on hER activity.We observed no agonistic activity of o,p'-DDE in any of the yeast models used.These results suggest that OP, BPA, and o,p'-DDT exert their estrogen-like activity through the ER in a manner similar to that of estradiol, and the coactivator RIP140 markedly potentiates this activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0521, USA.

ABSTRACT
We used three yeast genetic systems to investigate the estrogen-like activity of octylphenol (OP), bisphenol-A (BPA), o,p'-DDT, and o, p'-DDE to induce human estrogen receptor (hER) dimerization and transcriptional activation. We have demonstrated that OP, BPA, and o, p'-DDT can induce hER ligand-dependent dimerization using a yeast two-hybrid assay. All three xenoestrogens, plus estradiol, enhanced estrogen response element (ERE)-dependent transcriptional activation of hER. In the presence of receptor interacting protein 140 (RIP140), ERE-dependent activity was dramatically amplified by 100-fold for estradiol, OP, BPA, and o,p'-DDT. A yeast whole-cell [(3)H]estradiol binding assay was developed to determine the site of interaction on the hER. We determined nonspecific binding by parallel incubations run in the presence of 5 microM unlabelled estradiol in PCY2 yeast. At the concentrations tested, unlabeled estradiol, OP, and BPA displaced [(3)H]estradiol in this binding assay, whereas the concentrations of o,p'-DDT and o,p'-DDE tested were insufficient to inhibit binding. Incubating yeast in the presence of increasing concentrations of estradiol and OP (1 microM) or BPA (1 microM) neither blocked nor altered the effect of estradiol on hER activity. We observed no agonistic activity of o,p'-DDE in any of the yeast models used. These results suggest that OP, BPA, and o,p'-DDT exert their estrogen-like activity through the ER in a manner similar to that of estradiol, and the coactivator RIP140 markedly potentiates this activity.

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Environmental estrogens induce transcriptionally active estrogen receptor dimers in yeast: activity potentiated by the coactivator RIP140.

Sheeler CQ, Dudley MW, Khan SA - Environ. Health Perspect. (2000)

© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC1637889&req=5

Bottom Line: Incubating yeast in the presence of increasing concentrations of estradiol and OP (1 microM) or BPA (1 microM) neither blocked nor altered the effect of estradiol on hER activity.We observed no agonistic activity of o,p'-DDE in any of the yeast models used.These results suggest that OP, BPA, and o,p'-DDT exert their estrogen-like activity through the ER in a manner similar to that of estradiol, and the coactivator RIP140 markedly potentiates this activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0521, USA.

ABSTRACT
We used three yeast genetic systems to investigate the estrogen-like activity of octylphenol (OP), bisphenol-A (BPA), o,p'-DDT, and o, p'-DDE to induce human estrogen receptor (hER) dimerization and transcriptional activation. We have demonstrated that OP, BPA, and o, p'-DDT can induce hER ligand-dependent dimerization using a yeast two-hybrid assay. All three xenoestrogens, plus estradiol, enhanced estrogen response element (ERE)-dependent transcriptional activation of hER. In the presence of receptor interacting protein 140 (RIP140), ERE-dependent activity was dramatically amplified by 100-fold for estradiol, OP, BPA, and o,p'-DDT. A yeast whole-cell [(3)H]estradiol binding assay was developed to determine the site of interaction on the hER. We determined nonspecific binding by parallel incubations run in the presence of 5 microM unlabelled estradiol in PCY2 yeast. At the concentrations tested, unlabeled estradiol, OP, and BPA displaced [(3)H]estradiol in this binding assay, whereas the concentrations of o,p'-DDT and o,p'-DDE tested were insufficient to inhibit binding. Incubating yeast in the presence of increasing concentrations of estradiol and OP (1 microM) or BPA (1 microM) neither blocked nor altered the effect of estradiol on hER activity. We observed no agonistic activity of o,p'-DDE in any of the yeast models used. These results suggest that OP, BPA, and o,p'-DDT exert their estrogen-like activity through the ER in a manner similar to that of estradiol, and the coactivator RIP140 markedly potentiates this activity.

Show MeSH
Related in: MedlinePlus