title: Translational frameshifting mediated by a viral sequence in plant cells.
abstract: It has been proposed that the polymerase gene of barley yellow dwarf virus and related viruses is expressed by a ribosomal frameshift event during translation. The 5' end of this gene overlaps with the 3' end of an upstream gene that is in a different reading frame. The region of overlap is similar to sequences in retro- and coronaviruses that are known to express their polymerase genes by frameshifting. This overlap region includes a "shifty" heptanucleotide, followed by a highly structured region that may contain a pseudoknot. Sequences of 115 or 144 base pairs that span this region from barley yellow dwarf virus (PAV serotype) genomic RNA were introduced into a plasmid, so that a reporter gene could be expressed in plant cells only if a minus one (-1) frameshift event occurred. Frameshifting was detected at a rate of approximately 1%. This frameshifting was abolished when the stop codon at the 3' end of the upstream open reading frame was deleted. A sequence expected to form a strong stem-loop immediately upstream of the frameshift site was unnecessary for frameshifting, and initiation at AUG codons within the stem-loop appeared to be inhibited. Like viruses that infect hosts in other kingdoms, plant viruses also can induce frameshifting in translation of their genes.
authors.affiliation: Plant Pathology Department, Iowa State University, Ames 50011.
authors.forename: V
authors.initials: V
authors.lastname: Brault
authors.forename: W A
authors.initials: WA
authors.lastname: Miller
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003062:Codon; D016368:Frameshift Mutation; D005966:Glucuronidase / Q000032:analysis / Q000235:genetics*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016366:Open Reading Frames; D010942:Plant Viruses / Q000235:genetics* / Q000302:isolation & purification; D010944:Plants / Q000235:genetics / Q000382:microbiology*; D010957:Plasmids; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D011523:Protoplasts / Q000502:physiology
chemical_list: D003062:Codon; D009838:Oligodeoxyribonucleotides; D005966:Glucuronidase