Abstract
We describe an assay employing the competitive binding of estrogen receptor (ER) with basal transcription factors on a constitutive promoter (cytomegalovirus-hormone response element[s]-chloramphenicol acetyltransferase [CMV-(HRE)n-CAT, containing a hormone response element(s) between the TATA box and the start site of transcription]) to examine the DNA-binding ability of the human ER in whole cells. We used this promoter interference assay to examine the DNA binding of ER in cell lines containing high and low levels of endogenous ER, as well as in CHO cells expressing wild-type and mutant ERs from cotransfected expression vectors. The ER is capable of binding to the promoter interference constructs in the absence of added ligand, and estrogen (estradiol) or antiestrogen (trans-hydroxytamoxifen or ICI 164,384) enhances or stabilizes this interaction. The binding of unoccupied ER to reporter gene activation plasmids results in ligand-independent transactivation, presumably due to the TAF-1 function of the receptor. DNA binding of ER in the absence of ligand is observed in cells containing endogenous ER, or expressed ER, and occurs in cells with high or low receptor contents. Although estrogen- and antiestrogen-occupied ER complexes bind to DNA and reduce the template promoter activity, the extent of suppression achieved by ICI-bound ERs is consistently less than that achieved with the other ligands, presumably caused by the fact that ICI rapidly reduces the level of ER in most of the cells examined. However, the ICI-ER complexes that remain are in sufficient quantity to bind to gene activation reporter constructs, and in these cells, ICI still behaves as a pure antagonist of gene transcription and does not activate reporter genes. Hence, obstruction of ER DNA binding or reduction of ER in target cells may contribute to, but cannot fully explain, the pure antagonist character of the antiestrogen ICI 164,384. In addition, DNA binding by the ER alone is clearly not sufficient for ensuring full activation of transcription and argues for an intermediate in the receptor activation of promoters.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Andersson S., Davis D. L., Dahlbäck H., Jörnvall H., Russell D. W. Cloning, structure, and expression of the mitochondrial cytochrome P-450 sterol 26-hydroxylase, a bile acid biosynthetic enzyme. J Biol Chem. 1989 May 15;264(14):8222–8229. [PubMed] [Google Scholar]
- Aronica S. M., Katzenellenbogen B. S. Progesterone receptor regulation in uterine cells: stimulation by estrogen, cyclic adenosine 3',5'-monophosphate, and insulin-like growth factor I and suppression by antiestrogens and protein kinase inhibitors. Endocrinology. 1991 Apr;128(4):2045–2052. doi: 10.1210/endo-128-4-2045. [DOI] [PubMed] [Google Scholar]
- Berkenstam A., Glaumann H., Martin M., Gustafsson J. A., Norstedt G. Hormonal regulation of estrogen receptor messenger ribonucleic acid in T47Dco and MCF-7 breast cancer cells. Mol Endocrinol. 1989 Jan;3(1):22–28. doi: 10.1210/mend-3-1-22. [DOI] [PubMed] [Google Scholar]
- Berry M., Metzger D., Chambon P. Role of the two activating domains of the oestrogen receptor in the cell-type and promoter-context dependent agonistic activity of the anti-oestrogen 4-hydroxytamoxifen. EMBO J. 1990 Sep;9(9):2811–2818. doi: 10.1002/j.1460-2075.1990.tb07469.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown M., Sharp P. A. Human estrogen receptor forms multiple protein-DNA complexes. J Biol Chem. 1990 Jul 5;265(19):11238–11243. [PubMed] [Google Scholar]
- Carson-Jurica M. A., Schrader W. T., O'Malley B. W. Steroid receptor family: structure and functions. Endocr Rev. 1990 May;11(2):201–220. doi: 10.1210/edrv-11-2-201. [DOI] [PubMed] [Google Scholar]
- Chang T. C., Nardulli A. M., Lew D., Shapiro D. J. The role of estrogen response elements in expression of the Xenopus laevis vitellogenin B1 gene. Mol Endocrinol. 1992 Mar;6(3):346–354. doi: 10.1210/mend.6.3.1584211. [DOI] [PubMed] [Google Scholar]
- Chen C., Okayama H. High-efficiency transformation of mammalian cells by plasmid DNA. Mol Cell Biol. 1987 Aug;7(8):2745–2752. doi: 10.1128/mcb.7.8.2745. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clarke R., Brünner N., Katzenellenbogen B. S., Thompson E. W., Norman M. J., Koppi C., Paik S., Lippman M. E., Dickson R. B. Progression of human breast cancer cells from hormone-dependent to hormone-independent growth both in vitro and in vivo. Proc Natl Acad Sci U S A. 1989 May;86(10):3649–3653. doi: 10.1073/pnas.86.10.3649. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Elliston J. F., Tsai S. Y., O'Malley B. W., Tsai M. J. Superactive estrogen receptors. Potent activators of gene expression. J Biol Chem. 1990 Jul 15;265(20):11517–11521. [PubMed] [Google Scholar]
- Fawell S. E., Lees J. A., White R., Parker M. G. Characterization and colocalization of steroid binding and dimerization activities in the mouse estrogen receptor. Cell. 1990 Mar 23;60(6):953–962. doi: 10.1016/0092-8674(90)90343-d. [DOI] [PubMed] [Google Scholar]
- Fawell S. E., White R., Hoare S., Sydenham M., Page M., Parker M. G. Inhibition of estrogen receptor-DNA binding by the "pure" antiestrogen ICI 164,384 appears to be mediated by impaired receptor dimerization. Proc Natl Acad Sci U S A. 1990 Sep;87(17):6883–6887. doi: 10.1073/pnas.87.17.6883. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gibson M. K., Nemmers L. A., Beckman W. C., Jr, Davis V. L., Curtis S. W., Korach K. S. The mechanism of ICI 164,384 antiestrogenicity involves rapid loss of estrogen receptor in uterine tissue. Endocrinology. 1991 Oct;129(4):2000–2010. doi: 10.1210/endo-129-4-2000. [DOI] [PubMed] [Google Scholar]
- Gorman C. M., Moffat L. F., Howard B. H. Recombinant genomes which express chloramphenicol acetyltransferase in mammalian cells. Mol Cell Biol. 1982 Sep;2(9):1044–1051. doi: 10.1128/mcb.2.9.1044. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Greene G. L., Sobel N. B., King W. J., Jensen E. V. Immunochemical studies of estrogen receptors. J Steroid Biochem. 1984 Jan;20(1):51–56. doi: 10.1016/0022-4731(84)90188-2. [DOI] [PubMed] [Google Scholar]
- Herbomel P., Bourachot B., Yaniv M. Two distinct enhancers with different cell specificities coexist in the regulatory region of polyoma. Cell. 1984 Dec;39(3 Pt 2):653–662. doi: 10.1016/0092-8674(84)90472-0. [DOI] [PubMed] [Google Scholar]
- Hu M. C., Davidson N. The inducible lac operator-repressor system is functional in mammalian cells. Cell. 1987 Feb 27;48(4):555–566. doi: 10.1016/0092-8674(87)90234-0. [DOI] [PubMed] [Google Scholar]
- King W. J., Greene G. L. Monoclonal antibodies localize oestrogen receptor in the nuclei of target cells. Nature. 1984 Feb 23;307(5953):745–747. doi: 10.1038/307745a0. [DOI] [PubMed] [Google Scholar]
- Kumar V., Chambon P. The estrogen receptor binds tightly to its responsive element as a ligand-induced homodimer. Cell. 1988 Oct 7;55(1):145–156. doi: 10.1016/0092-8674(88)90017-7. [DOI] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Lees J. A., Fawell S. E., Parker M. G. Identification of two transactivation domains in the mouse oestrogen receptor. Nucleic Acids Res. 1989 Jul 25;17(14):5477–5488. doi: 10.1093/nar/17.14.5477. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Martinez E., Wahli W. Cooperative binding of estrogen receptor to imperfect estrogen-responsive DNA elements correlates with their synergistic hormone-dependent enhancer activity. EMBO J. 1989 Dec 1;8(12):3781–3791. doi: 10.1002/j.1460-2075.1989.tb08555.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McDonnell D. P., Nawaz Z., O'Malley B. W. In situ distinction between steroid receptor binding and transactivation at a target gene. Mol Cell Biol. 1991 Sep;11(9):4350–4355. doi: 10.1128/mcb.11.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meyer M. E., Gronemeyer H., Turcotte B., Bocquel M. T., Tasset D., Chambon P. Steroid hormone receptors compete for factors that mediate their enhancer function. Cell. 1989 May 5;57(3):433–442. doi: 10.1016/0092-8674(89)90918-5. [DOI] [PubMed] [Google Scholar]
- Pham T. A., Elliston J. F., Nawaz Z., McDonnell D. P., Tsai M. J., O'Malley B. W. Antiestrogen can establish nonproductive receptor complexes and alter chromatin structure at target enhancers. Proc Natl Acad Sci U S A. 1991 Apr 15;88(8):3125–3129. doi: 10.1073/pnas.88.8.3125. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Picard D., Khursheed B., Garabedian M. J., Fortin M. G., Lindquist S., Yamamoto K. R. Reduced levels of hsp90 compromise steroid receptor action in vivo. Nature. 1990 Nov 8;348(6297):166–168. doi: 10.1038/348166a0. [DOI] [PubMed] [Google Scholar]
- Picard D., Kumar V., Chambon P., Yamamoto K. R. Signal transduction by steroid hormones: nuclear localization is differentially regulated in estrogen and glucocorticoid receptors. Cell Regul. 1990 Feb;1(3):291–299. doi: 10.1091/mbc.1.3.291. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Power R. F., Mani S. K., Codina J., Conneely O. M., O'Malley B. W. Dopaminergic and ligand-independent activation of steroid hormone receptors. Science. 1991 Dec 13;254(5038):1636–1639. doi: 10.1126/science.1749936. [DOI] [PubMed] [Google Scholar]
- Read L. D., Greene G. L., Katzenellenbogen B. S. Regulation of estrogen receptor messenger ribonucleic acid and protein levels in human breast cancer cell lines by sex steroid hormones, their antagonists, and growth factors. Mol Endocrinol. 1989 Feb;3(2):295–304. doi: 10.1210/mend-3-2-295. [DOI] [PubMed] [Google Scholar]
- Reese J. C., Katzenellenbogen B. S. Characterization of a temperature-sensitive mutation in the hormone binding domain of the human estrogen receptor. Studies in cell extracts and intact cells and their implications for hormone-dependent transcriptional activation. J Biol Chem. 1992 May 15;267(14):9868–9873. [PubMed] [Google Scholar]
- Reese J. C., Katzenellenbogen B. S. Differential DNA-binding abilities of estrogen receptor occupied with two classes of antiestrogens: studies using human estrogen receptor overexpressed in mammalian cells. Nucleic Acids Res. 1991 Dec 11;19(23):6595–6602. doi: 10.1093/nar/19.23.6595. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Reese J. C., Katzenellenbogen B. S. Mutagenesis of cysteines in the hormone binding domain of the human estrogen receptor. Alterations in binding and transcriptional activation by covalently and reversibly attaching ligands. J Biol Chem. 1991 Jun 15;266(17):10880–10887. [PubMed] [Google Scholar]
- Schena M., Yamamoto K. R. Mammalian glucocorticoid receptor derivatives enhance transcription in yeast. Science. 1988 Aug 19;241(4868):965–967. doi: 10.1126/science.3043665. [DOI] [PubMed] [Google Scholar]
- Tora L., Mullick A., Metzger D., Ponglikitmongkol M., Park I., Chambon P. The cloned human oestrogen receptor contains a mutation which alters its hormone binding properties. EMBO J. 1989 Jul;8(7):1981–1986. doi: 10.1002/j.1460-2075.1989.tb03604.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tora L., White J., Brou C., Tasset D., Webster N., Scheer E., Chambon P. The human estrogen receptor has two independent nonacidic transcriptional activation functions. Cell. 1989 Nov 3;59(3):477–487. doi: 10.1016/0092-8674(89)90031-7. [DOI] [PubMed] [Google Scholar]
- Tzukerman M., Zhang X. K., Hermann T., Wills K. N., Graupner G., Pfahl M. The human estrogen receptor has transcriptional activator and repressor functions in the absence of ligand. New Biol. 1990 Jul;2(7):613–620. [PubMed] [Google Scholar]
- Wrenn C. K., Katzenellenbogen B. S. Cross-linking of estrogen receptor to chromatin in intact MCF-7 human breast cancer cells: optimization and effect of ligand. Mol Endocrinol. 1990 Nov;4(11):1647–1654. doi: 10.1210/mend-4-11-1647. [DOI] [PubMed] [Google Scholar]