title: The C terminus of lettuce mosaic potyvirus cylindrical inclusion helicase interacts with the viral VPg and with lettuce translation eukaryotic initiation factor 4E.
abstract: Recessive resistance to lettuce mosaic virus (LMV) is conferred in lettuce by the mo1 gene, encoding the eukaryotic translation initiation factor 4E (eIF4E). The C terminus of the viral cylindrical inclusion helicase (CI-Cter), together with the VPg, is involved directly in overcoming mo1 resistance. In this study, recombinant LMV VPg and CI-Cter proteins from wild-type or resistance-breaking isolates were expressed and purified from Escherichia coli. The allelic forms of eIF4E from susceptible or resistant lettuce cultivars were produced similarly and these proteins were used in ELISA-based assays to demonstrate the in vitro binding of the various forms of LMV CI-Cter to both lettuce eIF4E and LMV VPg proteins. All combinations tested displayed significant and specific interactions, and the interaction between the C-terminal part of the LMV CI and eIF4E was confirmed in vivo in bimolecular fluorescence complementation assays. Higher interaction signals for both CI-eIF4E and CI-VPg were observed for LMV-E, indicating that the eIF4E interaction network involving CI and VPg appears to be stronger in the case of this resistance-breaking isolate. This could suggest the need for a minimal interaction threshold for infection success in resistant lettuce, but more precise measurement of the interaction parameters linking eIF4E, VPg and CI is needed in order to reinforce such a hypothesis.
authors.affiliation: Equipe de Virologie, INRA and Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, BP81, 33883 Villenave d'Ornon cedex, France.
authors.forename: G
authors.initials: G
authors.lastname: Tavert-Roudet
authors.affiliation: Equipe de Virologie, INRA and Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, BP81, 33883 Villenave d'Ornon cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Abdul-Razzak
authors.affiliation: Equipe de Virologie, INRA and Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, BP81, 33883 Villenave d'Ornon cedex, France.
authors.forename: B
authors.initials: B
authors.lastname: Doublet
authors.affiliation: Equipe de Virologie, INRA and Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, BP81, 33883 Villenave d'Ornon cedex, France.
authors.forename: J
authors.initials: J
authors.lastname: Walter
authors.affiliation: Equipe de Virologie, INRA and Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, BP81, 33883 Villenave d'Ornon cedex, France.
authors.forename: T
authors.initials: T
authors.lastname: Delaunay
authors.affiliation: Equipe de Virologie, INRA and Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, BP81, 33883 Villenave d'Ornon cedex, France.
authors.forename: S
authors.initials: S
authors.lastname: German-Retana
authors.affiliation: Equipe de Virologie, INRA and Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, BP81, 33883 Villenave d'Ornon cedex, France.
authors.forename: T
authors.initials: T
authors.lastname: Michon
authors.affiliation: Equipe de Virologie, INRA and Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, BP81, 33883 Villenave d'Ornon cedex, France.
authors.forename: O
authors.initials: O
authors.lastname: Le Gall
authors.affiliation: Equipe de Virologie, INRA and Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, BP81, 33883 Villenave d'Ornon cedex, France.
authors.forename: T
authors.initials: T
authors.lastname: Candresse
mesh_terms: D020816:Amino Acid Motifs; D004265:DNA Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D039561:Eukaryotic Initiation Factor-4E / Q000235:genetics / Q000378:metabolism*; D018545:Lactuca / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D010935:Plant Diseases / Q000235:genetics / Q000821:virology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D017800:Potyvirus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D011485:Protein Binding; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D039561:Eukaryotic Initiation Factor-4E; D010940:Plant Proteins; D014764:Viral Proteins; D004265:DNA Helicases