title: N-glycosylation gene DPAGT1 is a target of the Wnt/beta-catenin signaling pathway.
abstract: Protein N-glycosylation and the Wnt/β-catenin signaling pathways play critical roles in development and cancer. Although N-glycosylation has been shown to influence Wnt signaling through its effects on Wnt ligands, it is unclear whether the Wnt/β-catenin pathway impacts protein N-glycosylation. In this study, we show that promoters of the first N-glycosylation gene, DPAGT1, from Chinese hamster ovary (CHO), Madin-Darby canine kidney (MDCK), and human epidermoid carcinoma (A253) cells contain the T-cell factor/lymphoid enhancer-binding factor (TCF/LEF) consensus sequence. Treatment of cells with a Wnt activator, lithium chloride, up-regulated DPAGT1 transcript levels that correlated with an increase in the β-catenin abundance. Furthermore, exposure of cells to a Wnt receptor ligand, Wnt3a, resulted in an increase in the DPAGT1 transcript levels that was abrogated by the Wnt inhibitor, Dickkopf-1. DNA mobility shift assays revealed specific protein complexes at the DPAGT1 TCF/LEF binding region that were competed off with antibodies to either Tcf3/4 or β-catenin. Chromatin immunoprecipitation analysis confirmed the presence of β-catenin at the DPAGT1 promoter in vivo. In addition, the DPAGT1 TCF/LEF sequence drove the expression of the luciferase reporter gene. Furthermore, up-regulation of DPAGT1 transcripts by Wnt3a led to altered N-glycosylation of E-cadherin. Interestingly, the DPAGT1 TCF/LEF sequence also interacted with γ-catenin, a close homologue of β-catenin, although not in a lithium chloride-dependent manner. Our results provide the first evidence that the Wnt/β-catenin signaling pathway regulates the metabolic pathway of protein N-glycosylation by targeting DPAGT1 expression. Moreover, they suggest the existence of another regulatory mechanism involving the interaction of Tcf with γ-catenin at the DPAGT1 promoter.
authors.affiliation: Department of Molecular and Cell Biology, Boston University Medical Campus, Boston, Massachusetts 02118, USA.
authors.forename: Pritam K
authors.initials: PK
authors.lastname: Sengupta
authors.forename: Meghan P
authors.initials: MP
authors.lastname: Bouchie
authors.forename: Maria A
authors.initials: MA
authors.lastname: Kukuruzinska
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D020816:Amino Acid Motifs; D000818:Animals; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D016466:CHO Cells; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D051180:Desmoplakins / Q000235:genetics / Q000378:metabolism; D004285:Dogs; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology*; D006031:Glycosylation / Q000187:drug effects; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D018021:Lithium Chloride / Q000494:pharmacology; D017351:N-Acetylglucosaminyltransferases / Q000096:biosynthesis* / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D000073940:Transcription Factor 4; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*; D060508:Wnt3 Protein; D060509:Wnt3A Protein; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D051185:gamma Catenin
chemical_list: D000276:Adjuvants, Immunologic; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D015820:Cadherins; D051180:Desmoplakins; D036341:Intercellular Signaling Peptides and Proteins; D018021:Lithium Chloride; D017351:N-Acetylglucosaminyltransferases; D000073940:Transcription Factor 4; D014157:Transcription Factors; D051153:Wnt Proteins; D060508:Wnt3 Protein; D060509:Wnt3A Protein; D051176:beta Catenin; D051185:gamma Catenin; C501126:DKK1 protein, human; C495292:JUP protein, human; C407909:TCF3 protein, human; C532096:TCF4 protein, human; C555510:WNT3A protein, human; C047835:dolichyl-phosphate alpha-N-acetylglucosaminyltransferase