The transcription factor GATA-4 regulates cytochrome P4502C19 gene expression
| Autor: | Jana Nekvindová, Isa Cavaco, Souren Mkrtchian, Yvonne Hofmann, Rasmus Steen Pedersen, Magnus Ingelman-Sundberg, Jessica Mwinyi |
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| Rok vydání: | 2009 |
| Předmět: |
Chromatin Immunoprecipitation
Transcription Genetic Electrophoretic Mobility Shift Assay Biology General Biochemistry Genetics and Molecular Biology Gene Expression Regulation Enzymologic Mice Cell Line Tumor Animals Humans Electrophoretic mobility shift assay General Pharmacology Toxicology and Pharmaceutics Luciferases Promoter Regions Genetic Transcription factor Reporter gene Binding Sites GATA4 GATA2 Wild type Promoter General Medicine Hep G2 Cells Molecular biology GATA4 Transcription Factor Cytochrome P-450 CYP2C19 GATA2 Transcription Factor embryonic structures Mutation GATA transcription factor Aryl Hydrocarbon Hydroxylases |
| Zdroj: | Life sciences. 86(19-20) |
| ISSN: | 1879-0631 |
| Popis: | Aims Cytochrome P4502C19 (CYP2C19) is an important enzyme involved in the metabolism of antiulcer drugs and antidepressants. However, despite the well documented drug-dependent variability of CYP2C19 expression, the mechanisms underlying the regulation of the enzyme remain unknown. In this study we investigated whether the transcription factor family GATA is involved in the regulation of CYP2C19 gene expression. Main methods We identified a novel putative GATA binding site at position –165/–156 within the CYP2C19 gene promoter. 5′-Deletion fragments of the CYP2C19 promoter containing wild type or mutant variants of this GATA binding site were co-transfected with expression vectors encoding the transcription factors GATA-4 or GATA-2 and analyzed using dual luciferase gene reporter assays in HepG2 and Huh-7 hepatoma cells. Electrophoretic Mobility Shift Assay (EMSA) and Chromatin Immunoprecipitations (ChIP) were performed to proof a sequence-specific interaction of GATA proteins with the putative GATA binding site. Key findings The wild type fragments of CYP2C19 promoter were highly upregulated by GATA-4 and GATA-2 in luciferase gene reporter assay, whereas mutations introduced into the GATA binding sites caused a significant activity loss. Similar attenuation was observed upon co-transfection of GATA-4 with a known co-regulator of GATA activity, FOG-2. EMSA analysis revealed a sequence-specific binding of GATA-4 and GATA-6 to the wild type GATA binding site. In addition, the association of GATA-4 with the CYP2C19 promoter was confirmed by ChIP analysis. Significance These data indicate that GATA-4 plays an important role in the transcriptional regulation of CYP2C19 expression. |
| Databáze: | OpenAIRE |
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