Regulation of RNA translation in potato virus X RNA-coat protein complexes: The key role of the N-terminal segment of the protein

The efficiency of in vitro translation of the potato virus X (PVX) RNA was studied for viral ribonucleoprotein complexes (vRNP) assembled from the genomic RNA and the viral coat protein (CP). In vRNP particles the 5'-proximal RNA segments were encapsidated into the CP, which formed helical head...

Full description

Saved in:
Bibliographic Details
Published in:Molecular biology (New York) 2006-07, Vol.40 (4), p.628-634
Main Authors: Karpova, O V, Arkhipenko, M V, Zayakina, O V, Nikitin, NA, Kiselyova, OI, Kozlovsky, S V, Rodionova, N P, Atabekov, J G
Format: Article
Language:English
Subjects:
Amino acids
Coat protein
genomics
Peptides
Phosphorylation
Potato virus X
Protein kinase
Proteins
Regulation
Ribonucleoproteins
RNA
RNA viruses
Translation
Virions
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The efficiency of in vitro translation of the potato virus X (PVX) RNA was studied for viral ribonucleoprotein complexes (vRNP) assembled from the genomic RNA and the viral coat protein (CP). In vRNP particles the 5'-proximal RNA segments were encapsidated into the CP, which formed helical headlike structures differing in length. Translation of the PVX RNA was completely suppressed upon incubation with PVX CP and was activated within vRNPs assembled in vitro with two CP forms, differing in the modification of the N-terminal peptide containing the main phosphorylation site(s) for Thr/Ser protein kinases. It was shown that CP phosphorylation activates RNA translation within vRNPs and that the removal of the N-terminal peptide of CP suppresses activation, but CP still acts as a translational suppressor. This fact made it possible to suppose that the replacement of Ser/Thr by amino acid residues that are not subject to phosphorylation in the N-terminal peptide of CP of the mutant PVX (PVX-ST) completely inhibits RNA translation within vRNP. However, experiments disproved this assumption: PVX-ST RNA was efficiently translated within native virions, RNA of the wild-type (wt) PVX was efficiently translated in heterogeneous vRNP (wtRNA + PVX-ST CP), and the opposite result (repression of translation) was obtained for another heterogeneous vRNP (PVX-ST RNA + wtCP). Therefore, the N-terminal CP peptide located on the surface of the PVX virion or vRNP particles plays a key role in the activation of viral RNA translation.
ISSN:0026-8933
1608-3245
DOI:10.1134/S0026893306040157