An unusual internal ribosomal entry site of inverted symmetry directs expression of a potato leafroll polerovirus replication-associated protein.
Potato leafroll polerovirus (PLRV) genomic RNA acts as a polycistronic mRNA for the production of proteins P0, P1, and P2 translated from the 5'-proximal half of the genome. Within the P1 coding region we identified a 5-kDa replication-associated protein 1 (Rap1) essential for viral multiplication. An internal ribosome entry site (IRES) with unusual structure and location was identified that regulates Rap1 translation. Core structural elements for internal ribosome entry include a conserved AUG codon and a downstream GGAGAGAGAGG motif with inverted symmetry. Reporter gene expression in potato protoplasts confirmed the internal ribosome entry function. Unlike known IRES motifs, the PLRV IRES is located completely within the coding region of Rap1 at the center of the PLRV genome.
Jaag
Hannah Miriam
HM
Fraunhofer-Institut für Molekularbiologie, Abteilung Genom und Proteomforschung, Auf dem Aberg 1, 57392 Schmallenberg, Germany.
Kawchuk
Lawrence
L
Rohde
Wolfgang
W
Fischer
Rainer
R
Emans
Neil
N
Prüfer
Dirk
D
D000595:Amino Acid Sequence; D001483:Base Sequence; D018387:Codon, Initiator / Q000235:genetics; D016679:Genome, Viral; D017793:Luteovirus / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012367:RNA, Viral / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D012270:Ribosomes / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000821:virology; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication / Q000235:genetics
D018387:Codon, Initiator; D012367:RNA, Viral; D014764:Viral Proteins