title: Differential regulation of the mouse and human Wnt5a alternative promoters A and B.
abstract: Wnt5a is an extracellular glycoprotein that activates Wnt signaling pathways, important in development and tissue homeostasis. Wnt5a expression is often misregulated during cancer progression. In this study, we analyzed the transcriptional regulation of two of the Wnt5a alternative promoters, termed A and B. Transient transfection of promoter A and B luciferase reporter constructs in to NIH3T3 and Caco-2 cells indicated that the separated promoters are both functional and that 300-450 base pair (bp) of upstream sequence is sufficient for activity. Promoter B constructs displayed distinct patterns of expression in the two cell types. The endogenous levels of promoter A-derived transcripts were found to be greater than the promoter B transcripts by four- to sixfold in fibroblast cells. Treatment of NIH3T3 cells with tumor necrosis factor (TNF)-alpha leads to an increase in both promoter A and B activities, but promoter B was more responsive. Using inhibitors of TNF-alpha effector proteins, we provide evidence that the transcription factor nuclear factor-kappaB and the MEK1/2 and p38 kinases have distinct roles in determining the activity levels of promoters, A and B. These results support the conclusion that Wnt5a promoters, A and B, are differentially regulated and provide a model for complex transcriptional regulation of Wnt5a.
authors.affiliation: Department of Biology, The University of North Carolina at Greensboro, Greensboro, North Carolina 27412, USA. kskatula@uncg.edu
authors.forename: Karen S
authors.initials: KS
authors.lastname: Katula
authors.forename: Nicole B
authors.initials: NB
authors.lastname: Joyner-Powell
authors.forename: Chia-Chi
authors.initials: CC
authors.lastname: Hsu
authors.forename: Amber
authors.initials: A
authors.lastname: Kuk
mesh_terms: D000818:Animals; D001483:Base Sequence; D002070:Butadienes / Q000494:pharmacology; D018938:Caco-2 Cells; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D048369:MAP Kinase Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048370:MAP Kinase Kinase 2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D041681:NIH 3T3 Cells; D009570:Nitriles / Q000494:pharmacology; D010655:Phenylenediamines / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D051153:Wnt Proteins / Q000235:genetics*; D000071818:Wnt-5a Protein; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: C549066:4-methyl-N1-(3-phenylpropyl)benzene-1,2-diamine; D002070:Butadienes; D004791:Enzyme Inhibitors; D016328:NF-kappa B; D009570:Nitriles; D010655:Phenylenediamines; D011518:Proto-Oncogene Proteins; D014409:Tumor Necrosis Factor-alpha; C113580:U 0126; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C438615:Wnt5a protein, mouse; D008156:Luciferases; C482128:MAP2K2 protein, human; D048051:p38 Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482125:MAP2K1 protein, human