title: Interaction of androgen receptors with androgen response element in intact cells. Roles of amino- and carboxyl-terminal regions and the ligand.
abstract: Promoter interference assay was employed to examine in intact cells the roles of the functional domains of androgen receptor (AR) and the ligand for specific DNA interactions using a cytomegalovirus-(androgen response element)-chloramphenicol acetyltransferase reporter (pCMV-ARE2-CAT). Native rat and human ARs interfered with pCMV-ARE2-CAT expression in a hormone-dependent fashion. Low steroid-independent interference seemed to occur because of the ligand binding domain (LBD), which was transcriptionally inhibitory also in a heterologous context. AR devoid of LBD (rARDelta641-902) decreased pCMV-ARE2-CAT activity by 50%. The rARDelta46-408 mutant devoid of the NH2-terminal transcription activation region exhibited ligand-dependent promoter interference of a similar magnitude. Ligand and DNA binding-deficient mutants (hARM807R and rARC562G, respectively) did not influence pCMV-ARE2-CAT expression, although hARM807R binds to ARE in vitro. Non-steroidal anti-androgens casodex and hydroxyflutamide antagonized agonist-dependent promoter interference, whereas cyproterone acetate, RU 56187, RU 57073, and RU 59063 were partial agonists/antagonists. Collectively, interaction of ARs with ARE in intact cells does not require the presence of the COOH-terminal or NH2-terminal domain and/or their interaction. In the context of native AR, however, the androgen-induced conformational change in LBD is mandatory for generation of a transcriptionally competent receptor that binds to DNA in intact cells.
authors.affiliation: Institute of Biomedicine, Department of Physiology, University of Helsinki, FIN-00014 Helsinki, Finland.
authors.forename: U
authors.initials: U
authors.lastname: Karvonen
authors.forename: P J
authors.initials: PJ
authors.lastname: Kallio
authors.forename: O A
authors.initials: OA
authors.lastname: Jänne
authors.forename: J J
authors.initials: JJ
authors.lastname: Palvimo
mesh_terms: D000726:Androgen Antagonists / Q000378:metabolism; D000728:Androgens / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D017930:Genes, Reporter; D006801:Humans; D008024:Ligands; D011401:Promoter Regions, Genetic; D051381:Rats; D011944:Receptors, Androgen / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D000726:Androgen Antagonists; D000728:Androgens; D008024:Ligands; D011944:Receptors, Androgen; D004247:DNA