The eukaryotic initiation factor 4E (eIF4E) emerged recently as a target fo
r different types of regulation affecting translation. In animal and yeast
cells, eIF4E-binding proteins modulate the availability of eIF4E. A search
for plant eIF4E-binding proteins from Arabidopsis thaliana using the yeast
genetic interaction system identified a clone encoding a lipoxygenase type
2 (AtLOX2). In vitro and in vivo biochemical assays confirm an interaction
between AtLOX2 and plant eIF4E(iso) factor. A two-hybrid assay revealed tha
t AtLOX2 is also able to interact with both wheat initiation factors 4E and
4E(iso). Deletion analysis maps the region of AtLOX2 involved in interacti
on with AteIF(iso)4E between amino acids 175 and 232. A sequence related to
the conserved motif present in several eIF4E-binding proteins was found in
this region. Furthermore, the wheat p86 subunit, a component of the plant
translation eIF(iso)4F complex, was found to interfere with the AteIF(iso)4
E-AtLOX2 interaction suggesting that p86 and AtLOX2 compete for the same si
te on eIF(iso)4E. These results may reflect a link between eIF4Es factors m
ediating translational control with LOX2 activity, which is probably conser
ved throughout the plant kingdom.