title: Selective interactions of Kruppel-like factor 9/basic transcription element-binding protein with progesterone receptor isoforms A and B determine transcriptional activity of progesterone-responsive genes in endometrial epithelial cells.
abstract: The Sp/KLF transcription factor basic transcription element-binding protein (BTEB1) regulates gene transcription by binding to GC-rich sequence motifs present in the promoters of numerous tissue-specific as well as housekeeping genes. Similar to other members of this family, BTEB1 can act as a transactivator or transrepressor depending on cell and promoter context, although the molecular mechanism underlying these distinct activities remains unclear. Here we report that BTEB1 can mediate signaling pathways involving the nuclear receptor for the steroid hormone progesterone in endometrial epithelial cells by its selective interaction with the progesterone receptor (PR) isoforms, PR-A and PR-B. Functional interaction with ligand-activated PR-B resulted in superactivation of PR-B transactivity, facilitated the recruitment of the transcriptional integrator CREB-binding protein within the PR-dimer, and was dependent on the structure of the ligand bound by PR-B. By contrast, BTEB1 did not influence agonist-bound PR-A transactivity, although it augmented PR-A inhibition of PR-B-mediated transactivation as well as potentiated ligand-independent PR-A transcriptional activity in the presence of CREB-binding protein. We also demonstrate similar positive modulatory actions of BTEB1-related family members Krüppel-like family (KLF) 13/FKLF2/BTEB3 and Sp1 on PR-B transactivity. Further, we provide support for the potential significance of the selective functional interactions of PR isoforms with BTEB1 in the peri-implantation uterus using mouse and pig models and in the breast cancer cell lines MCF-7 and T47D. Our results suggest a novel mechanism for the divergent physiological consequences of PR-A and PR-B on progesterone-dependent gene transcription in the uterus involving select KLF members.
authors.affiliation: Interdisciplinary Concentration in Animal Molecular and Cell Biology, University of Florida, Gainesville, FL 32611-0910, USA.
authors.forename: Xue-Lian
authors.initials: XL
authors.lastname: Zhang
authors.forename: Daying
authors.initials: D
authors.lastname: Zhang
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Michel
authors.forename: Jason L
authors.initials: JL
authors.lastname: Blum
authors.forename: Frank A
authors.initials: FA
authors.lastname: Simmen
authors.forename: Rosalia C M
authors.initials: RC
authors.lastname: Simmen
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D050882:CREB-Binding Protein; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D004717:Endometrium / Q000378:metabolism; D004847:Epithelial Cells; D005260:Female; D017930:Genes, Reporter; D005822:Genetic Vectors; D006801:Humans; D051741:Kruppel-Like Transcription Factors; D008024:Ligands; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011374:Progesterone / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020033:Protein Isoforms; D011980:Receptors, Progesterone / Q000737:chemistry / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016329:Sp1 Transcription Factor / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured; D014599:Uterus / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C489676:KLF9 protein, human; C489675:Klf9 protein, mouse; D051741:Kruppel-Like Transcription Factors; D008024:Ligands; D009687:Nuclear Proteins; D020033:Protein Isoforms; D011980:Receptors, Progesterone; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors; D011374:Progesterone; D050882:CREB-Binding Protein; C494363:CREBBP protein, human; C494364:Crebbp protein, mouse