Expression of the Rous sarcoma virus pol gene by ribosomal frameshifting Academic Article uri icon


MeSH Major

  • Avian Sarcoma Viruses
  • Gene Expression Regulation
  • Protein Biosynthesis
  • RNA-Directed DNA Polymerase
  • Ribosomes


  • The pol gene of Rous sarcoma virus is positioned downstream of the gag gene in a different, briefly overlapping reading frame; nevertheless, the primary translation product of pol is a gag-pol fusion protein. Two mechanisms, ribosomal frameshifting and RNA splicing, have been considered to explain this phenomenon. The frameshifting model is supported by synthesis of both gag protein and gag-pol fusion protein in a cell-free mammalian translation system programmed by a single RNA species that was synthesized from cloned viral DNA with a bacteriophage RNA polymerase. Under these conditions, the ratio of the gag protein to the fusion protein (about 20 to 1) is similar to that previously observed in infected cells, the frameshifting is specific for the gag-pol junction, and it is unaffected by large deletions in gag. In addition, synthesis of the fusion protein is ten times less efficient in an Escherichia coli cell-free translation system and cannot be explained by transcriptional errors or in vitro modification of the RNA. Ribosomal frameshifting may affect production of other proteins in higher eukaryotes, including proteins encoded by several retroviruses and transposable elements.

publication date

  • December 1985



  • Academic Article



  • eng

PubMed ID

  • 2416054

Additional Document Info

start page

  • 1237

end page

  • 42


  • 230


  • 4731