Poly(A)-Binding Protein Facilitates Translation of an Uncapped/Nonpolyadenylated Viral RNA by Binding to the 3′ Untranslated Region

• DOI: 10.1128/jvi.00538-12
• Publication Date: 2012-05-17T17:12:06Z
• Authors: Hiro-oki Iwakawa; Yuri Tajima; Takako Taniguchi; Masanori Kaido; Kazuyuki Mise; Yukihide Tomari; Hisaaki Taniguchi; Tetsuro Okuno
• Keywords: EIF4E; Eukaryotic translation

ABSTRACT Viruses employ an alternative translation mechanism to exploit cellular resources at the expense of host mRNAs and allow preferential translation. Plant RNA viruses often lack both a 5′ cap 3′ poly(A) tail in their genomic RNAs. Instead, cap-independent enhancer elements (CITEs) located untranslated region (UTR) mediate Although eukaryotic initiation factors (eIFs) or ribosomes have been shown bind 3′CITEs, our knowledge is still limited for mechanism, especially factors. Here, we searched that stimulate 3′CITE-mediated Red clover necrotic mosaic virus (RCNMV) RNA1 using aptamer-based one-step affinity chromatography, followed by mass spectrometry analysis. We identified poly(A)-binding protein (PABP) as one key players RCNMV RNA1. found PABP binds A-rich sequence (ARS) viral UTR. The ARS conserved among dianthoviruses. Mutagenesis tethering assay revealed PABP-ARS interaction stimulates also 3′CITE are important recruitment plant eIF4F eIFiso4F UTR 40S ribosomal subunit mRNA. Our results suggest dianthoviruses evolved substitutes efficient eIFs, PABP, uncapped/nonpolyadenylated