title: Upstream region of hepatitis B virus S gene responsible for transcriptional stimulation by dexamethasone.
abstract: Transcriptional regulation of hepatitis B virus (HBV) surface antigen (HBs Ag) gene was studied in human hepatoma-derived cell lines. Treatment with dexamethasone (Dex; 1 microM) induced an increase in the smaller HBs-mRNA initiated within Pre-S region encoding S and Pre-S2 proteins, but not the larger HBs-mRNA initiated in the further upstream encoding Pre-S1 protein. The Bg1II-MstII fragment (map position 2425-3201) in the upstream of the S gene was used as a transcriptional promoter of chloramphenicol acetyltransferase (CAT) gene. The CAT activity brought about by this construct in the transient assay was elevated by 5-fold in the presence of Dex. Deletion analysis localized the sequence required for the full response to Dex within a 590-base pair fragment in the upstream of the transcriptional initiation site of the smaller HBs-mRNA. And this fragment contained the binding site for the nuclear factor I (NF-I), which might have some role in Dex-dependent transcriptional stimulation.
authors.affiliation: Department of Bacteriology, Faculty of Medicine, University of Tokyo.
authors.forename: M
authors.initials: M
authors.lastname: Masuda
authors.forename: G
authors.initials: G
authors.lastname: Lee
authors.forename: T
authors.initials: T
authors.lastname: Yuasa
authors.forename: H
authors.initials: H
authors.lastname: Yoshikura
mesh_terms: D022762:CCAAT-Enhancer-Binding Proteins; D006528:Carcinoma, Hepatocellular / Q000382:microbiology; D004268:DNA-Binding Proteins / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology*; D005786:Gene Expression Regulation; D005814:Genes, Viral / Q000187:drug effects; D006515:Hepatitis B virus / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D008113:Liver Neoplasms; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000187:drug effects*; D014407:Tumor Cells, Cultured / Q000382:microbiology; D051840:Y-Box-Binding Protein 1
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D003907:Dexamethasone