eIF5A binds to translational machinery components and affects translation in yeast

• DOI: 10.1016/j.bbrc.2006.07.195
• Publication Date: 2006-08-08T16:46:30Z
• Authors: Cleslei F. Zanelli; Ana L.C. Maragno; Ana P.B. Gregio; Suzanne Komili; José R. Pandolfi; Carlos A. Mestriner; Wilton R. Lustri; Sandro R. Valentini
• Keywords: Protein Synthesis Inhibitors; 0303 health sciences; Saccharomyces cerevisiae Proteins; protein synthesis; Lysine; L11; Peptide Chain Elongation, Translational; translation; RNA-Binding Proteins; Eukaryotic Translation Initiation Factor 5A; Saccharomyces cerevisiae; P0; hypusine; 3. Good health; 03 medical and health sciences; ribosome; Peptide Initiation Factors; eEF2; Protein Biosynthesis; Mutation; eIF5A; Ribosomes

The putative translation factor eIF5A is essential for cell viability and is highly conserved from archebacteria to mammals. Although this protein was originally identified as a translation initiation factor, subsequent experiments did not support a role for eIF5A in general translation. In this work, we demonstrate that eIF-5A interacts with structural components of the 80S ribosome, as well as with the translation elongation factor 2 (eEF2). Moreover, eIF5A is further shown to cofractionate with monosomes in a translation-dependent manner. Finally, eIF5A mutants show altered polysome profiles and are sensitive to translation inhibitors. Our results re-establish a function for eIF5A in translation and suggest a role for this factor in translation elongation instead of translation initiation.