The Activating Enzyme of NEDD8 Inhibits Steroid Receptor Function

摘要: Coregulator proteins, coactivators and corepressors, have a profound influence on steroid receptor activity play role in regulating levels. To identify novel coregulators of nuclear receptors, we used the ligand-binding hinge region ER as bait yeast two-hybrid screen cDNA library derived from rat uterine luminal epithelium. We report cloning characterization encoding protein homologous to human ubiquitin-activating enzyme 3 (Uba3), catalytic subunit activating ubiquitin-like NEDD8 (neural precursor cellexpressed developmentally down-regulated) conjugation pathway (known neddylation). Sequence analysis revealed that Uba3 contains multiple (NR)-interacting motifs (NR boxes), which are known mediate interactions between coregulatory proteins ligandactivated NRs. Yeast glutathioneS-transferase pull-down assays demonstrated directly interacts with ligand-occupied ER. Transient transfection mammalian cells inhibited ER-mediated transactivation time-dependent fashion; had no effect initial events transcriptional activation by liganded ER, but it blocked progressive increase target gene expression during continuous stimulation. also AR PR receptor-independent pathway. An enzymatically silent form did not inhibit ER-induced transcription, Uba3-binding fragment amyloid protein-binding protein, other NEDD8-activating enzyme, partially overcame Uba3-mediated inhibition, demonstrating neddylation is required for its inhibition transactivation. Thus, inhibits transcription induced hormone receptors through mechanism involves Understanding mechanisms controlling responsiveness tissues, such uterus mammary gland, may lead insights therapeutic intervention. (Molecular Endocrinology 16: 315–330, 2002)