title: Identification of minimal sequences of the Rhopalosiphum padi virus 5' untranslated region required for internal initiation of protein synthesis in mammalian, plant and insect translation systems.
abstract: Rhopalosiphum padi virus (RhPV) is a member of the family Dicistroviridae. The genomes of viruses in this family contain two open reading frames, each preceded by distinct internal ribosome entry site (IRES) elements. The RhPV 5' IRES is functional in mammalian, insect and plant translation systems and can form 48S initiation complexes in vitro with just the mammalian initiation factors eIF2, eIF3 and eIF1. Large regions of the 5' untranslated region (UTR) can be deleted without affecting initiation-complex formation. The minimal sequences required for directing internal initiation in mammalian (rabbit reticulocyte lysate), plant (wheatgerm extract) and insect (Sf21 cells) translation systems have now been defined. A fragment (nt 426-579) from the 3' portion of the 5' UTR can direct translation in each of these translation systems. In addition, a distinct region (nt 300-429) is also active. Thus, unstructured regions within the 5' UTR seem to be critical for IRES function.
authors.affiliation: School of Biomedical and Molecular Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Groppelli
authors.affiliation: BBSRC Institute for Animal Health, Ash Road, Pirbright, Surrey GU24 0NF, UK.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Belsham
authors.affiliation: School of Biomedical and Molecular Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
authors.forename: Lisa O
authors.initials: LO
authors.lastname: Roberts
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics*; D000818:Animals; D001042:Aphids / Q000821:virology*; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D007304:Insect Viruses / Q000235:genetics* / Q000302:isolation & purification; D008322:Mammals / Q000821:virology; D010443:Peptide Chain Termination, Translational; D010944:Plants / Q000821:virology; D010957:Plasmids; D014176:Protein Biosynthesis; D014764:Viral Proteins / Q000096:biosynthesis
chemical_list: D020121:5' Untranslated Regions; D004279:DNA, Viral; D014764:Viral Proteins