Repression of liver-specific hepatitis B virus enhancer 2 activity by adenovirus E1A proteins.
Two regions of the hepatitis B virus (HBV) genome have been shown to display properties of a transcriptional enhancer. Enhancer 1 is active in most hepatoma lines examined as well as in some non-hepatocyte-derived cell lines. In contrast, enhancer 2 activity is strictly liver specific. In this study, we show that adenovirus E1A expression in the highly differentiated human hepatoma line Huh6 strongly inhibits HBV enhancer 2-stimulated transcription while having no effect on HBV enhancer 1 activity. A sequence motif in HBV enhancer 2 which is essential for its enhancer function is the target for E1A-mediated repression. The repression of HBV enhancer 2 activity is mediated through the N-terminal region of the E1A proteins known to bind a 300-kDa cellular protein. Our results suggest that HBV enhancer function may be modulated by a cellular mechanism similar to E1A-mediated transcriptional repression.
Chen
S T
ST
Department of Pediatrics, University of California, San Diego, La Jolla 92093-0634.
Su
H
H
Yee
J K
JK
D017500:Adenovirus E1A Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D015967:Gene Expression Regulation, Viral; D016679:Genome, Viral; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D007700:Kinetics; D008099:Liver / Q000382:microbiology*; D008113:Liver Neoplasms; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015183:Restriction Mapping; D014158:Transcription, Genetic; D014162:Transfection
D017500:Adenovirus E1A Proteins; D004279:DNA, Viral; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D015500:Chloramphenicol O-Acetyltransferase