title: UXT Is a LOX-PP Interacting Protein That Modulates Estrogen Receptor Alpha Activity in Breast Cancer Cells.
abstract: The lysyl oxidase proenzyme propeptide region (LOX-PP) is a tumor suppressor protein whose mechanism of action is not completely understood. Here, the Ubiquitously expressed Transcript (UXT) was identified in a yeast two-hybrid assay with LOX-PP as bait and confirmed as a novel LOX-PP associating protein. UXT, a prefoldin-like protein, is ubiquitous in human and mouse. Since UXT modulates androgen receptor transcriptional activity in prostate cancer, we studied its role in breast cancer. Breast tumors and derived cell lines overexpressed UXT. UXT was able to associate with the estrogen receptor alpha (ER) and decrease its transcriptional activity and target gene expression. Conversely, UXT knockdown increased ER element-dependent transcriptional activity. Ectopic LOX-PP relocalized UXT to the cytoplasm and decreased its stability. UXT ubiquitination and depletion in the presence of LOX-PP was rescued by a proteasomal inhibitor. In summary, proteasome-mediated turnover of UXT upon interaction with LOX-PP releases repression of ER transcriptional activity. J. Cell. Biochem. 118: 2347-2356, 2017. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts.
authors.forename: Nuria
authors.initials: N
authors.lastname: Sánchez-Morgan
authors.affiliation: Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Kathrin H
authors.initials: KH
authors.lastname: Kirsch
authors.affiliation: Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts.
authors.forename: Philip C
authors.initials: PC
authors.lastname: Trackman
authors.affiliation: Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts.
authors.forename: Gail E
authors.initials: GE
authors.lastname: Sonenshein
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002460:Cell Line; D045744:Cell Line, Tumor; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D047468:Immunoprecipitation; D061986:MCF-7 Cells; D051379:Mice; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D008249:Protein-Lysine 6-Oxidase / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D020798:Two-Hybrid System Techniques
chemical_list: D018797:Cell Cycle Proteins; D047628:Estrogen Receptor alpha; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; C118920:UXT protein, human; C568328:UXT protein, mouse; D008249:Protein-Lysine 6-Oxidase
keywords: BREAST CANCER; ESTROGEN RECEPTOR; LYSYL OXIDASE PROPEPTIDE; PROTEASOME; UXT