We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
A novel shuttling protein, 4E-T, mediates the nuclear import of the mRNA 5' cap-binding protein, eIF4E.
- Authors
Dostie, J; Ferraiuolo, M; Pause, A; Adam, S A; Sonenberg, N
- Abstract
The eukaryotic translation initiation factor 4E (eIF4E) plays an important role in the control of cell growth. eIF4E binds to the mRNA 5' cap structure m(7)GpppN (where N is any nucleotide), and promotes ribosome binding to the mRNA in the cytoplasm. However, a fraction of eIF4E localizes to the nucleus. Here we describe the cloning and functional characterization of a new eIF4E-binding protein, referred to as 4E-T (eIF4E-Transporter). We demonstrate that 4E-T is a nucleocytoplasmic shuttling protein that contains an eIF4E-binding site, one bipartite nuclear localization signal and two leucine-rich nuclear export signals. eIF4E forms a complex with the importin alphabeta heterodimer only in the presence of 4E-T. Overexpression of wild-type 4E-T, but not of a mutant defective for eIF4E binding, causes the nuclear accumulation of HA-eIF4E in cells treated with leptomycin B. Taken together, these results demonstrate that the novel nucleocytoplasmic shuttling protein 4E-T mediates the nuclear import of eIF4E via the importin alphabeta pathway by a piggy-back mechanism.
- Publication
The EMBO journal, 2000, Vol 19, Issue 12, p3142
- ISSN
0261-4189
- Publication type
Journal Article
- DOI
10.1093/emboj/19.12.3142