title: eIF5A has a function in the elongation step of translation in yeast.
abstract: The putative translation factor eIF5A is essential for cell viability and is highly conserved throughout evolution. Here, we describe genetic interactions between an eIF5A mutant and a translation initiation mutant (eIF4E) or a translation elongation mutant (eEF2). Polysome profile analysis of single and double mutants revealed that mutation in eIF5A reduces polysome run-off, contrarily to translation initiation mutants. Moreover, the polysome profile of an eIF5A mutant alone is very similar to that of a translation elongation mutant. Furthermore, depletion of eIF5A causes a significant decrease in total protein synthesis and an increase of the average ribosome transit time. Finally, we demonstrate that the formation of P bodies is inhibited in an eIF5A mutant, similarly to the effect of the translation elongation inhibitor cycloheximide. Taken together, these results not only reinforce a role for eIF5A in translation but also strongly support a function for eIF5A in the elongation step of protein synthesis.
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, São Paulo State University-UNESP, Faculdade de Ciências Farmacêuticas, Rodovia Araraquara-Jaú, km 01, Araraquara, SP 14801-902, Brazil.
authors.forename: Ana P B
authors.initials: AP
authors.lastname: Gregio
authors.forename: Veridiana P S
authors.initials: VP
authors.lastname: Cano
authors.forename: Juliana S
authors.initials: JS
authors.lastname: Avaca
authors.forename: Sandro R
authors.initials: SR
authors.lastname: Valentini
authors.forename: Cleslei F
authors.initials: CF
authors.lastname: Zanelli