title: Factors affecting translation at the programmed -1 ribosomal frameshifting site of Cocksfoot mottle virus RNA in vivo.
abstract: The ratio between proteins P27 and replicase of Cocksfoot mottle virus (CfMV) is regulated via a -1 programmed ribosomal frameshift (-1 PRF). A minimal frameshift signal with a slippery U UUA AAC heptamer and a downstream stem-loop structure was inserted into a dual reporter vector and directed -1 PRF with an efficiency of 14.4 +/- 1.9% in yeast and 2.4 +/- 0.7% in bacteria. P27-encoding CfMV sequence flanking the minimal frameshift signal caused approximately 2-fold increase in the -1 PRF efficiencies both in yeast and in bacteria. In addition to the expected fusion proteins, termination products ending putatively at the frameshift site were found in yeast cells. We propose that the amount of premature translation termination from control mRNAs played a role in determining the calculated -1PRF efficiency. Co-expression of CfMV P27 with the dual reporter vector containing the minimal frameshift signal reduced the production of the downstream reporter, whereas replicase co-expression had no pronounced effect. This finding allows us to propose that CfMV protein P27 may influence translation at the frameshift site but the mechanism needs to be elucidated.
authors.affiliation: Department of Applied Biology PO Box 27 University of Helsinki FIN-00014 Helsinki, Finland.
authors.forename: Katri
authors.initials: K
authors.lastname: Mäkeläinen
authors.forename: Kristiina
authors.initials: K
authors.lastname: Mäkinen
mesh_terms: D004926:Escherichia coli / Q000235:genetics; D018965:Frameshifting, Ribosomal; D015967:Gene Expression Regulation, Viral; D017930:Genes, Reporter; D010942:Plant Viruses / Q000235:genetics*; D012328:RNA Viruses / Q000235:genetics*; D012367:RNA, Viral / Q000737:chemistry; D012324:RNA-Dependent RNA Polymerase / Q000096:biosynthesis / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014764:Viral Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase