A heptanucleotide sequence mediates ribosomal frameshifting in mammalian cells.
Ribosomal frameshifting is an essential requirement for replication of many viruses and retrovirus-like elements. It is regarded as a potential target for antiretroviral therapy. It has been shown that the frameshifting event takes place in the -1 direction within a sequence, the slippery sequence, which is usually followed by structured RNA. To distinguish between the basic sequence requirements and the modulating elements in intact cells, we have established a sensitive assay system for quantitative determination of ribosomal frameshifting in mammalian cell culture. In this assay system, the gag and pol genes of human immunodeficiency virus type 1 are replaced by the genes for the functional enzymes beta-galactosidase and luciferase, respectively. The sensitivity of the test system allows us to demonstrate for the first time that the slippery sequence, a heptanucleotide, is sufficient to mediate a basal level of ribosomal frameshifting independent of its position within a gene. The stem-loop sequence serves only as a positive modulator. These data indicate that frameshifting could also occur during translation of cellular genes in which a slippery sequence is present within the reading frame. The resulting putative transframe proteins might have a functional importance for cellular processes.
Reil
H
H
Genetics of Eukaryotes, Gesellschaft für Biotechnologische Forschung mbH, Braunschweig, Germany.
Kollmus
H
H
Weidle
U H
UH
Hauser
H
H
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002472:Cell Transformation, Viral; D004247:DNA / Q000235:genetics / Q000378:metabolism; D016368:Frameshift Mutation; D015750:Genes, gag; D015751:Genes, pol; D015497:HIV-1 / Q000235:genetics / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008322:Mammals; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection; D014779:Virus Replication; D001616:beta-Galactosidase / Q000378:metabolism
D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D004247:DNA; D008156:Luciferases; D001616:beta-Galactosidase