title: Protein kinase C activates human lipocalin-type prostaglandin D synthase gene expression through de-repression of notch-HES signaling and enhancement of AP-2 beta function in brain-derived TE671 cells.
abstract: Here we investigated the regulatory mechanism of lipocalin-type prostaglandin D synthase (L-PGDS) gene expression in human TE671 (medulloblastoma of cerebellum) cells. Reporter analysis of the promoter region from -730 to +75 of the human L-PGDS gene demonstrated that deletion or mutation of the N-box at -337 increased the promoter activity 220-300%. The N-box was bound by Hes-1, a mammalian homologue of Drosophila Hairy and enhancer of split, as examined by electrophoretic mobility shift assay and chromatin immunoprecipitation assay. Functional expression of the Notch intracellular domain significantly increased Hes-1 expression and decreased L-PGDS expression level in TE671 cells. Moreover, knock-down of Hes-1 mRNA by RNA interference significantly enhanced the L-PGDS mRNA level, indicating that the L-PGDS gene expression is repressed by the Notch-Hes signaling. When the AP-2 element at -98 of the promoter region was deleted or mutated, the promoter activity was drastically decreased to approximately 10% of normal. The AP-2 element was bound by AP-2beta dominantly expressed in TE671 cells, according to the results of electrophoretic mobility shift assay and chromatin immunoprecipitation assay. L-PGDS expression was induced by 12-O-tetradecanoylphorbol-13-acetate in TE671 cells, and this induction was inhibited by a protein kinase C inhibitor. Stimulation of TE671 cells with 12-O-tetradecanoylphorbol-13-acetate or transfection with protein kinase Calpha expression vector induced phosphorylation of Hes-1, inhibition of DNA binding of Hes-1 to the N-box, and activation of the AP-2beta function to up-regulate L-PGDS gene expression. These results reveal a novel transcriptional regulatory mechanism responsible for the high level expression of the human L-PGDS gene in TE671 cells.
authors.affiliation: Department of Molecular Behavioral Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka 565-0874, Japan.
authors.forename: Ko
authors.initials: K
authors.lastname: Fujimori
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kadoyama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Urade
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins; D001921:Brain / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D004794:Enzyme Repression / Q000187:drug effects / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018398:Homeodomain Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D054834:Lipocalins; D008527:Medulloblastoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D011493:Protein Kinase C / Q000502:physiology*; D017434:Protein Structure, Tertiary / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D051880:Receptors, Notch; D012097:Repressor Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D050656:Transcription Factor AP-2; D000072056:Transcription Factor HES-1; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D019746:Intramolecular Oxidoreductases; D054834:Lipocalins; D008565:Membrane Proteins; D011493:Protein Kinase C; D012333:RNA, Messenger; D051880:Receptors, Notch; D012097:Repressor Proteins; D013755:Tetradecanoylphorbol Acetate; D050656:Transcription Factor AP-2; D000072056:Transcription Factor HES-1; D014157:Transcription Factors; C493677:TFAP2B protein, human; C078493:HES1 protein, human; C022466:prostaglandin R2 D-isomerase