Liganded androgen receptor interaction with beta-catenin: nuclear co-localization and modulation of transcriptional activity in neuronal cells

• Published in: The Journal of biological chemistry 2002-06, Vol.277 (23), p.20702-20710
• Main Authors: Pawlowski, John E, Ertel, Jessica R, Allen, Melissa P, Xu, Mei, Butler, Cheryl, Wilson, Elizabeth M, Wierman, Margaret E
• Format: Article
• Language: English
• Subjects: Androgen Antagonists - pharmacology; Animals; beta Catenin; Blotting, Western; Cell Line; Cell Nucleus - metabolism; COS Cells; Cytoskeletal Proteins - metabolism; Estrogen Receptor alpha; Immunohistochemistry; Ligands; Mice; Neurons - metabolism; Precipitin Tests; Promoter Regions, Genetic; Protein Transport; Receptors, Androgen - metabolism; Receptors, Estrogen - metabolism; Receptors, Glucocorticoid - metabolism; Receptors, Progesterone - metabolism; Trans-Activators; Transcription, Genetic; Two-Hybrid System Techniques
• ISSN: 0021-9258
• DOI: 10.1074/jbc.M200545200

A yeast two-hybrid assay was employed to identify androgen receptor (AR) protein partners in gonadotropin-releasing hormone neuronal cells. By using an AR deletion construct (AR-(Delta371-485)) as a bait, beta-catenin was identified as an AR-interacting protein from a gonadotropin-releasing hormone neuronal cell library. Immunolocalization of co-transfected AR and FLAG-beta-catenin demonstrated that FLAG-beta-catenin was predominantly cytoplasmic in the absence of androgen. In the presence of 5alpha-dihydrotestosterone, FLAG-beta-catenin completely co-localized to the nucleus with AR. This effect was specific to AR because liganded progesterone, glucocorticoid, or estrogen alpha receptors did not translocate FLAG-beta-catenin to the nucleus. Agonist-bound AR was required because the AR antagonists casodex and hydroxyflutamide failed to translocate beta-catenin. Time course experiments demonstrated that co-translocation occurred with similar kinetics. Nuclear co-localization was independent of the glycogen synthase kinase-3beta, p42/44 ERK mitogen-activated protein kinase, and phosphatidylinositol 3-kinase pathways because inhibitors of these pathways had no effect. Transcription assays demonstrated that liganded AR repressed beta-catenin/T cell factor-responsive reporter gene activity. Conversely, co-expression of beta-catenin/T cell factor repressed AR stimulation of AR-responsive reporter gene activity. Our data suggest that liganded AR shuttles beta-catenin to the nucleus and that nuclear interaction of AR with beta-catenin may modulate transcriptional activity in androgen target tissues.