Liver-specific expression of hepatitis B virus is determined by the combined action of the core gene promoter and the enhancer.

AUTOR(ES)

Honigwachs, J

RESUMO

The hepatitis B virus (HBV) enhancer and the core gene promoter regulate the expression of the core and polymerase genes, as well as of the 3.5-kilobase pregenomic RNA. RNA analysis and chloramphenicol acetyltransferase gene expression by plasmids carrying the HBV enhancer linked to the heterologous beta-globin or simian virus 40 early promoter demonstrated that the HBV enhancer is 3- to 20-fold preferentially expressed in human liver cells. Core gene promoter activity was mapped to a 100-base-pair fragment which was shown to be sufficient for accurate initiation of transcription. The partial tissue specificity of this promoter was demonstrated by transient transfection into various cell lines with a plasmid containing the core gene promoter linked to the heterologous simian virus 40 enhancer. When the HBV core gene promoter was examined under the control of the HBV enhancer, there was high tissue specificity in that activity could be observed only in differentiated human liver cells. These results suggest that the strict tissue specificity of HBV gene expression is determined by the combinatorial action of these two elements.

Documentos Relacionados

• Binding of a liver-specific factor to the human albumin gene promoter and enhancer.
• Multiple liver-specific factors bind to the hepatitis B virus core/pregenomic promoter: trans-activation and repression by CCAAT/enhancer binding protein.
• Functional analysis of a liver-specific enhancer of the hepatitis B virus.
• Repression of liver-specific hepatitis B virus enhancer 2 activity by adenovirus E1A proteins.
• Activity of the rat liver-specific aldolase B promoter is restrained by HNF3.