title: Epidermal-growth-factor-dependent phosphorylation and ubiquitinylation of MAGE-11 regulates its interaction with the androgen receptor.
abstract: The androgen receptor (AR) is a ligand-activated transcription factor that interacts with coregulatory proteins during androgen-dependent gene regulation. Melanoma antigen gene protein 11 (MAGE-11) is an AR coregulator that specifically binds the AR NH(2)-terminal FXXLF motif and modulates the AR NH(2)- and carboxyl-terminal N/C interaction to increase AR transcriptional activity. Here we demonstrate that epidermal growth factor (EGF) signaling increases androgen-dependent AR transcriptional activity through the posttranslational modification of MAGE-11. EGF in the presence of dihydrotestosterone stabilizes the AR-MAGE complex through the site-specific phosphorylation of MAGE-11 at Thr-360 and ubiquitinylation at Lys-240 and Lys-245. The time-dependent EGF-induced increase in AR transcriptional activity by MAGE-11 is mediated through AR activation functions 1 and 2 in association with the increased turnover of AR and MAGE-11. The results reveal a dynamic mechanism whereby growth factor signaling increases AR transcriptional activity through the covalent modification of an AR-specific coregulatory protein. Sequence conservation of the MAGE-11 phosphorylation and ubiquitinylation sites throughout the MAGE gene family suggests common regulatory mechanisms for this group of cancer-testis antigens.
authors.affiliation: Laboratories for Reproductive Biology, CB 7500, University of North Carolina, Chapel Hill, NC 27599-7500, USA.
authors.forename: Suxia
authors.initials: S
authors.lastname: Bai
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Wilson
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D020816:Amino Acid Motifs; D000818:Animals; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000378:metabolism*; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D013196:Dihydrotestosterone / Q000737:chemistry / Q000378:metabolism*; D016889:Endometrial Neoplasms / Q000473:pathology; D004815:Epidermal Growth Factor / Q000502:physiology*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D046912:Multiprotein Complexes; D009363:Neoplasm Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D025941:Protein Interaction Mapping; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D011944:Receptors, Androgen / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D054875:Ubiquitination
chemical_list: C410798:AR protein, human; D000951:Antigens, Neoplasm; C110882:MAGEA11 protein, human; D046912:Multiprotein Complexes; D009363:Neoplasm Proteins; D011944:Receptors, Androgen; D011993:Recombinant Fusion Proteins; D013196:Dihydrotestosterone; D004815:Epidermal Growth Factor