Eukaryotic Initiation Factor (eIF) 4F Binding to Barley Yellow Dwarf Virus (BYDV) 3′-Untranslated Region Correlates with Translation Efficiency

Abstract

Background:Little is known about BYDV protein synthesis initiation mechanisms. Results: eIF4F binding correlates with 3Ј BTE translation efficiency and is enthalpically and entropically favorable. Conclusion: Binding of eIF4F to the 3Ј BTE is important for efficient BYDV translation. Significance: Binding of eIF4F to the 3Ј-UTR to initiate assembly of the protein synthesis initiation complex is a novel mechanism that may be used by other viruses containing a 3Ј BTE.

Cis- and trans-regulation of luteovirus gene expression by the 3′ end of the viral genome

“…The distribution of these elements does not always correlate with phylogenetic relationships of the viruses, suggesting recent and frequent recombination among the 3’ UTRs of tombusvirids (Simon and Miller, 2013). Where studied, it appears that all of them bind a surface of eIF4F with affinity that appears to be higher than binding of capped mRNA to eIF4F (Banerjee and Goss, 2014; Gazo et al, 2004; Nicholson et al, 2010; Treder et al, 2008; Wang et al, 2011). Upon binding of eIF4F, the 40S ribosomal subunit is recruited, either to the 3’ CITE directly (Yuan et al, 2012) or possibly to the 5’ UTR after the factor-bound CITE has base-paired with the 5’ UTR and placed eIF4F in the proximity of the 5’ end of the RNA (Rakotondrafara et al, 2006).…”

“…The 3’ CITE of luteoviruses, the BTE, binds eIF4G (Kd for the BYDV BTE = 177 nM) on which it depends to facilitate translation (Banerjee and Goss, 2014; Treder et al, 2008). eIF4E is not necessary for BTE-mediated translation, although it enhances the activity of eIF4G by about 25% in a wheat germ translation extract.…”

Recruitment of the 40S Ribosome Subunit to the 3′-Untranslated Region (UTR) of a Viral mRNA, via the eIF4 Complex, Facilitates Cap-independent Translation

“…Although it was shown previously that the 3Ј-BTE interacts specifically with eIF4F with a very high binding affinity (K d ϳ37 nM) (24,32) and that this binding affinity correlates with translational efficiency (32), the mechanism of ribosome recruitment and the role of associated eIFs during this event remain unclear. As the next step in the establishment of a ribosome recruitment mechanism in BYDV translation, we have quantitatively characterized interactions between the 40S subunit with wild type and mutant forms of the BYDV 3Ј-BTE and 5Ј-UTR alone and in the presence of different eIFs.…”

“…Previously, we reported the use of fluorescence quenching and anisotropy experiments to study the equilibrium binding between different mRNAs and eIFs (mRNA-eIF interactions) or between mRNAs and ribosomes (32,(55)(56)(57). In this study, we use these approaches to determine the equilibrium dissociation constants (K d values) for the interactions between 40S ribosomal subunits and 3Ј-BTE, 5Ј-UTR, and 3Ј-BTEBF RNAs (3Ј-BTEBF is a translationally inactive mutant of the BTE, containing a four-base duplication of GAUC in the 17-nt CS (31)) and the effects of different eIFs on 40S-3Ј-BTE interactions.…”

“…1B) (31). Translation initiation factor eIF4G binds the 3Ј-BTE with high affinity (24,32) and protects SL-I from modification by SHAPE reagents (33). The loop of stemloop III (3Ј-SL-III) of the 3Ј-BTE forms a long distance RNA-RNA "kissing" stem-loop base-pairing interaction with a loop in the 5Ј-end of the mRNA (25,34) (Fig.…”