Nuclear factor 1 family members interact with hepatocyte nuclear factor 1alpha to synergistically activate L-type pyruvate kinase gene transcription
| Autor: | Masayoshi Imagawa, Tamio Noguchi, Takashi Noaki, Shin-Ichi Satoh, Tatsuya Ishigure, Shigehiro Osada, Kazuya Yamada, Naoyuki Miura |
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| Rok vydání: | 2005 |
| Předmět: |
Male
endocrine system Chromatin Immunoprecipitation Transcription Genetic Response element Blotting Western Pyruvate Kinase Oligonucleotides Biology Biochemistry Rats Sprague-Dawley Sp3 transcription factor Genes Reporter Animals Humans Immunoprecipitation Hepatocyte Nuclear Factor 1-alpha Rats Wistar Enhancer Promoter Regions Genetic Molecular Biology Transcription factor Cells Cultured DNA Primers Glutathione Transferase Binding Sites General transcription factor Models Genetic Promoter Cell Biology TCF4 DNA Molecular biology Protein Structure Tertiary Rats Hepatocyte nuclear factors NFI Transcription Factors Liver Mutation Hepatocytes Mutagenesis Site-Directed HeLa Cells Plasmids Protein Binding Transcription Factors |
| Zdroj: | The Journal of biological chemistry. 280(48) |
| ISSN: | 0021-9258 |
| Popis: | Transcription of hepatic L-type pyruvate kinase (L-PK) gene is cell type-specific and is under the control of various nutritional conditions. The L-PK gene contains multiple cis-regulatory elements located within a 170-bp upstream region necessary for these regulations. These elements can synergistically stimulate L-PK gene transcription, although their mechanisms are largely unknown. Because nuclear factor (NF) 1 family members bind to specific cis-regulatory elements known as L-IIA and L-IIB and hepatocyte nuclear factor (HNF) 1alpha binds to the adjacent element L-I, we examined the functional and physical interactions between these two transcription factors. Reporter gene assay showed that these two factors synergistically activated the L-PK promoter containing the 5'-flanking region up to -189. Although two NF1-binding sites are required for the maximum synergistic effect of NF1 family members with HNF1alpha, significant functional interaction between the two factors was observed in the L-PK promoter containing two mutated NF1-binding sites and also in the promoter containing only the HNF1alpha-binding site, raising the possibility that NF1 proteins function as HNF1alpha co-activators. Chromatin immunoprecipitation assay revealed that both NF1 proteins and HNF1alpha bound to the promoter region of the L-PK gene in vivo. In vitro binding assay confirmed that NF1 proteins directly interacted mainly with the homeodomain of HNF1alpha via their DNA-binding domains. This interaction enhanced HNF1alpha binding to the L-I element and was also observed in rat liver by co-immunoprecipitation assay. Thus, we conclude that cooperative interaction between NF1 family members and HNF1alpha plays an important role in hepatic L-PK transcription. |
| Databáze: | OpenAIRE |
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