title: Ligand-specific dynamics of the androgen receptor at its response element in living cells.
abstract: Androgens have key roles in normal physiology and in male sexual differentiation as well as in pathological conditions such as prostate cancer. Androgens act through the androgen receptor (AR), which is a ligand-modulated transcription factor. Antiandrogens block AR function and are widely used in disease states, but little is known about their mechanism of action in vivo. Here, we describe a rapid differential interaction of AR with target genomic sites in living cells in the presence of agonists which coincides with the recruitment of BRM ATPase complex and chromatin remodeling, resulting in transcriptional activation. In contrast, the interaction of antagonist-bound or mutant AR with its target was found to be kinetically different: it was dramatically faster, occurred without chromatin remodeling, and resulted in the lack of transcriptional inhibition. Fluorescent resonance energy transfer analysis of wild-type AR and a transcriptionally compromised mutant at the hormone response element showed that intramolecular interactions between the N and C termini of AR play a key functional role in vivo compared to intermolecular interactions between two neighboring ARs. These data provide a kinetic and mechanistic basis for regulation of gene expression by androgens and antiandrogens in living cells.
authors.affiliation: Department of Molecular Biosciences, University of Oslo, Postboks 1041 Blindern, 0316 Oslo, Norway.
authors.forename: Tove I
authors.initials: TI
authors.lastname: Klokk
authors.forename: Piotr
authors.initials: P
authors.lastname: Kurys
authors.forename: Cem
authors.initials: C
authors.lastname: Elbi
authors.forename: Akhilesh K
authors.initials: AK
authors.lastname: Nagaich
authors.forename: Anindya
authors.initials: A
authors.lastname: Hendarwanto
authors.forename: Thomas
authors.initials: T
authors.lastname: Slagsvold
authors.forename: Ching-Yi
authors.initials: CY
authors.lastname: Chang
authors.forename: Gordon L
authors.initials: GL
authors.lastname: Hager
authors.forename: Fahri
authors.initials: F
authors.lastname: Saatcioglu
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D000726:Androgen Antagonists / Q000494:pharmacology; D000728:Androgens / Q000494:pharmacology; D000813:Anilides / Q000494:pharmacology; D000818:Animals; D045744:Cell Line, Tumor; D042002:Chromatin Assembly and Disassembly; D017373:Cyproterone Acetate / Q000494:pharmacology; D013196:Dihydrotestosterone / Q000494:pharmacology; D005260:Female; D036681:Fluorescence Recovery After Photobleaching; D005485:Flutamide / Q000031:analogs & derivatives / Q000494:pharmacology; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D008024:Ligands; D008156:Luciferases / Q000378:metabolism; D015674:Mammary Neoplasms, Animal / Q000473:pathology; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics; D015741:Metribolone / Q000494:pharmacology; D051379:Mice; D018715:Microscopy, Video; D015735:Mifepristone / Q000494:pharmacology; D008954:Models, Biological; D009570:Nitriles / Q000494:pharmacology; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011944:Receptors, Androgen / Q000187:drug effects / Q000378:metabolism*; D020218:Response Elements / Q000502:physiology*; D013739:Testosterone / Q000494:pharmacology; D014105:Tosyl Compounds / Q000494:pharmacology; D014158:Transcription, Genetic
chemical_list: D000726:Androgen Antagonists; D000728:Androgens; D000813:Anilides; D008024:Ligands; D009570:Nitriles; D011944:Receptors, Androgen; D014105:Tosyl Compounds; D013196:Dihydrotestosterone; D049452:Green Fluorescent Proteins; D015741:Metribolone; C014290:hydroxyflutamide; D015735:Mifepristone; D013739:Testosterone; D017373:Cyproterone Acetate; D005485:Flutamide; C053541:bicalutamide; D008156:Luciferases