The ubiquitous transcription factor Oct-1 and the liver-specific factor HNF-1 are both required to activate transcription of a hepatitis B virus promoter.
The liver-specific transcription factor HNF-1 activates transcription of several mammalian hepatocyte-specific genes. The hepatitis B virus preS1 promoter shows hepatocyte specificity, which has been ascribed to binding of HNF-1 to a cognate DNA sequence upstream of the TATA box. We show here that there is an adjacent site that binds the ubiquitous transcription factor Oct-1. Both the Oct-1 and HNF-1 sites are necessary for liver-specific transcription of the preS1 promoter, but neither site alone activates transcription. The Oct-1 site is also necessary for activation of the preS1 promoter in HeLa cells, expressing transfected HNF-1. Our results show that while Oct-1 is not restricted to hepatocytes, it nevertheless can play a critical role in the expression of a liver-specific gene.
Zhou
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Department of Pathology, University of California School of Medicine, San Francisco 94143-0506.
Yen
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D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics*; D015967:Gene Expression Regulation, Viral; D006367:HeLa Cells; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics*; D051537:Hepatocyte Nuclear Factor 1; D051538:Hepatocyte Nuclear Factor 1-alpha; D051539:Hepatocyte Nuclear Factor 1-beta; D051863:Host Cell Factor C1; D006801:Humans; D066298:In Vitro Techniques; D008099:Liver / Q000502:physiology; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D050811:Octamer Transcription Factor-1; D009841:Oligonucleotides / Q000737:chemistry; D011498:Protein Precursors / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014162:Transfection
D004268:DNA-Binding Proteins; C497692:HCFC1 protein, human; C496487:HNF1A protein, human; C496495:HNF1B protein, human; D006514:Hepatitis B Surface Antigens; D051538:Hepatocyte Nuclear Factor 1-alpha; D051863:Host Cell Factor C1; D009687:Nuclear Proteins; D050811:Octamer Transcription Factor-1; D009841:Oligonucleotides; C494165:POU2F1 protein, human; D011498:Protein Precursors; D014157:Transcription Factors; C050806:presurface protein 1, hepatitis B surface antigen; D051537:Hepatocyte Nuclear Factor 1; D051539:Hepatocyte Nuclear Factor 1-beta