title: A Tcf/Lef element within the enhancer region of the human NANOG gene plays a role in promoter activation.
abstract: NANOG is a homeodomain-containing transcription factor that is essential for the maintenance of pluripotency and self-renewal in embryonic stem cells. However, the molecular mechanisms underlying the regulation of NANOG expression in human cells remain largely unknown. Here, we investigated the role of Tcf/Lef response elements located in the enhancer of the human NANOG gene. We found that forced expression of Lef1 or β-catenin stimulated human NANOG promoter activity, while shRNA-mediated knockdown of β-catenin reduced Lef1-induced NANOG promoter activation. Deletion or mutation of the Tcf/Lef element within the enhancer region of the human NANOG gene completely abrogated Lef1-induced NANOG promoter activity. The results of a chromatin immunoprecipitation assay demonstrated that Lef1 and β-catenin bind to the Tcf/Lef element in the enhancer region of the NANOG gene. Forced expression of GSK-3β inhibited basal, Lef1-induced, and β-catenin-induced NANOG promoter activity, while treatment with the GSK-3β inhibitor SB216763 resulted in the accumulation of β-catenin and NANOG protein. Furthermore, Dvl-1-induced NANOG promoter activity was abrogated by the expression of β-catenin shRNA. Stable overexpression of Dvl-1 caused β-catenin and NANOG to accumulate. These results indicate that the Tcf/Lef response element in the enhancer region of the human NANOG gene is able to stimulate NANOG gene transcription.
authors.affiliation: Department of Biomedical Science and Technology, Research Center for Transcription Control, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Chang Gun
authors.initials: CG
authors.lastname: Kim
authors.forename: Il-Yup
authors.initials: IY
authors.lastname: Chung
authors.forename: Yoongho
authors.initials: Y
authors.lastname: Lim
authors.forename: Young Han
authors.initials: YH
authors.lastname: Lee
authors.forename: Soon Young
authors.initials: SY
authors.lastname: Shin
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000072261:Dishevelled Proteins; D004742:Enhancer Elements, Genetic; D017930:Genes, Reporter; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D057809:HEK293 Cells; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D051821:Lymphoid Enhancer-Binding Factor 1 / Q000378:metabolism; D000071317:Nanog Homeobox Protein; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051820:TCF Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D051176:beta Catenin / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C000606578:DVL1 protein, human; D000072261:Dishevelled Proteins; D018398:Homeodomain Proteins; C497573:LEF1 protein, human; D051821:Lymphoid Enhancer-Binding Factor 1; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D010750:Phosphoproteins; D051820:TCF Transcription Factors; D051176:beta Catenin; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3