Open AccessA fraction of the mRNA 5' cap-binding protein, eukaryotic initiation factor 4E, localizes to the nucleus.
Author(s) -
Flavio Lejbkowicz,
C Goyer,
André Darveau,
Sonia Néron,
Réal Lemieux,
Nahum Sonenberg
Publication year - 1992
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.89.20.9612
Subject(s) - initiation factor , messenger rna , eif4e , eukaryotic initiation factor , microbiology and biotechnology , biology , translation (biology) , eukaryotic translation initiation factor 4 gamma , precursor mrna , rna splicing , rna binding protein , eukaryotic translation , poly(a) binding protein , eukaryotic ribosome , eif4a1 , p bodies , nuclear protein , rna , biochemistry , transcription factor , gene
The 5' cap structure m7GpppN (where N is any nucleotide) is a ubiquitous feature of cellular eukaryotic mRNAs. The cap is multifunctional as it is involved in translation, nucleocytoplasmic transport, splicing, and stabilization of mRNA against 5' exonucleolytic degradation. The cap binding protein, eukaryotic initiation factor 4E (eIF-4E), is a translation initiation factor that binds to the cap structure and is part of a complex (eIF-4F) that promotes mRNA binding to ribosomes. Overexpression of eIF-4E in fibroblasts results in cell transformation. To test the hypothesis that some of the biological effects of eIF-4E might be effected by a nuclear function, we determined the cellular distribution of eIF-4E. By means of indirect immunofluorescence experiments using polyclonal and monoclonal antibodies against eIF-4E as well as transfected epitope-tagged eIF-4E, we demonstrate that a fraction of eIF-4E localizes to the nucleus. These results suggest that eIF-4E is also involved in a nuclear function.