Transcriptional activation of homologous and heterologous genes by the hepatitis B virus X gene product in cells permissive for viral replication.
The potential of the hepadnavirus X gene product to activate gene expression in trans was tested through a series of cotransfections of X expression vectors with a variety of potential targets for transactivation. The X gene products from human hepatitis B virus (HBV), woodchuck hepatitis virus, and ground squirrel hepatitis virus are all equally active in augmenting the expression of a wide array of target promoters in both permissive and nonpermissive cells. Using the HBV genome itself as the source of X protein, we demonstrate that transactivation of HBV and heterologous genes occurs when X protein is expressed in its native state during productive infection of permissive cells. Run-on transcription analysis indicates that this transactivation occurs at the level of primary transcription.
Colgrove
R
R
Department of Biochemistry and Biophysics, University of California Medical Center, San Francisco 94143-0502.
Simon
G
G
Ganem
D
D
D005814:Genes, Viral; D006515:Hepatitis B virus / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D012367:RNA, Viral / Q000096:biosynthesis; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000502:physiology*; D014779:Virus Replication
D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins