Regulation of human C-reactive protein gene expression by two synergistic IL-6 responsive elements.
To study the mechanism of interleukin-6 (IL-6) induction of human C-reactive protein (CRP) gene expression, we have utilized a human hepatoma (PLC/PRF/5) cell culture system to analyze the trans-acting factors which bind to the 300 bp 5'-flanking region of human CRP gene. In vitro gel mobility shift analyses and methylation interference assays demonstrated that NFIL-6 alpha interacted with two IL-6 responsive elements, and HNF-1 alpha and HNF-3/Octamer-like factors interacted with the downstream IL-6 responsive element in the human CRP promoter. In vivo functional analysis by transient transfection of plasmid constructs containing site-specific mutations in one or two IL-6 responsive elements in the CRP promoter fused to a reporter gene, chloramphenicol acetyl transferase (CAT), demonstrated that the binding of NFIL-6 alpha to two IL-6 responsive elements resulted in synergistic induction of the gene. When HNF-1 alpha or HNF-3/Octamer-like factors were independently bound to their corresponding sites, they had either a positive or negative effect, respectively, on IL-6 inducible transcriptional activity.
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Division of Allergenic Products and Parasitology, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, Maryland 20852-1448, USA.
Goldman
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D001483:Base Sequence; D001665:Binding Sites; D002097:C-Reactive Protein / Q000235:genetics*; D022762:CCAAT-Enhancer-Binding Proteins; D006528:Carcinoma, Hepatocellular; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D015342:DNA Probes; D004268:DNA-Binding Proteins / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D051537:Hepatocyte Nuclear Factor 1; D051538:Hepatocyte Nuclear Factor 1-alpha; D051539:Hepatocyte Nuclear Factor 1-beta; D051541:Hepatocyte Nuclear Factor 3-alpha; D006801:Humans; D015850:Interleukin-6 / Q000494:pharmacology*; D008745:Methylation; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured
D022762:CCAAT-Enhancer-Binding Proteins; D015342:DNA Probes; D004268:DNA-Binding Proteins; C496499:FOXA1 protein, human; C496487:HNF1A protein, human; C496495:HNF1B protein, human; D051538:Hepatocyte Nuclear Factor 1-alpha; D051541:Hepatocyte Nuclear Factor 3-alpha; D015850:Interleukin-6; D009687:Nuclear Proteins; D014157:Transcription Factors; D051537:Hepatocyte Nuclear Factor 1; D051539:Hepatocyte Nuclear Factor 1-beta; D002097:C-Reactive Protein; D015500:Chloramphenicol O-Acetyltransferase