Interaction in vitro between the proteinase of Tomato ringspot virus (genus Nepovirus) and the eukaryotic translation initiation factor iso4E from Arabidopsis thaliana.
Eukaryotic initiation factor eIF(iso)4E binds to the cap structure of mRNAs leading to assembly of the translation complex. This factor also interacts with the potyvirus VPg and this interaction has been correlated with virus infectivity. In this study, we show an interaction between eIF(iso)4E and the proteinase (Pro) of a nepovirus (Tomato ringspot virus; ToRSV) in vitro. The ToRSV VPg did not interact with eIF(iso)4E although its presence on the VPg-Pro precursor increased the binding affinity of Pro for the initiation factor. A major determinant of the interaction was mapped to the first 93 residues of Pro. Formation of the complex was inhibited by addition of m(7)GTP (a cap analogue), suggesting that Pro-containing molecules compete with cellular mRNAs for eIF(iso)4E binding. The possible implications of this interaction for translation and/or replication of the virus genome are discussed.
Centre de Microbiologie et Biotechnologie, INRS-Institut Armand-Frappier, 531 Boulevard des Prairies, Ville de Laval, Québec, CanadaH7V 1B71.
Simon
S
Léonard
Pacific Agri-Food Research Centre, 4200 Highway 97, Summerland, BC, CanadaV0H 1Z02.
Joan
J
Chisholm
Centre de Microbiologie et Biotechnologie, INRS-Institut Armand-Frappier, 531 Boulevard des Prairies, Ville de Laval, Québec, CanadaH7V 1B71.
Jean-François
JF
Laliberté
Pacific Agri-Food Research Centre, 4200 Highway 97, Summerland, BC, CanadaV0H 1Z02.
Hélène
H
Sanfaçon
D017360:Arabidopsis / Q000378:metabolism / Q000821:virology*; D001667:Binding, Competitive; D015153:Blotting, Western; D010450:Endopeptidases / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D039561:Eukaryotic Initiation Factor-4E; D018551:Solanum lycopersicum / Q000821:virology*; D017860:Nepovirus / Q000201:enzymology* / Q000472:pathogenicity; D010448:Peptide Initiation Factors / Q000378:metabolism*; D014176:Protein Biosynthesis; D012315:RNA Caps / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D014758:Viral Core Proteins / Q000378:metabolism; D014779:Virus Replication
D039561:Eukaryotic Initiation Factor-4E; D010448:Peptide Initiation Factors; D012315:RNA Caps; D012333:RNA, Messenger; D014758:Viral Core Proteins; D010450:Endopeptidases