Fertility and polarized cell growth depends on eIF5A for translation of polyproline-rich formins in Saccharomyces cerevisiae.

Abstract

eIF5A is an essential and evolutionary conserved translation elongation factor, which has recently been proposed to be required for the translation of proteins with consecutive prolines. The binding of eIF5A to ribosomes occurs upon its activation by hypusination, a modification that requires spermidine, an essential factor for mammalian fertility that also promotes yeast mating. We show that in response to pheromone, hypusinated eIF5A is required for shmoo formation, localization of polarisome components, induction of cell fusion proteins, and actin assembly in yeast. We also show that eIF5A is required for the translation of Bni1, a proline-rich formin involved in polarized growth during shmoo formation. Our data indicate that translation of the polyproline motifs in Bni1 is eIF5A dependent and this translation dependency is lost upon deletion of the polyprolines. Moreover, an exogenous increase in Bni1 protein levels partially restores the defect in shmoo formation seen in eIF5A mutants. Overall, our results identify eIF5A as a novel and essential regulator of yeast mating through formin translation. Since eIF5A and polyproline formins are conserved across species, our results also suggest that eIF5A-dependent translation of formins could regulate polarized growth in such processes as fertility and cancer in higher eukaryotes.

• Authors: Tianlu Li, Borja Belda-Palazón, Alejandro Ferrando, Paula Alepuz
• Journal: Genetics (Genetics) Vol. 197 Issue 4 Pg. 1191-200 (Aug 2014) ISSN: 1943-2631 [Electronic] United States
• PMID: 24923804 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 by the Genetics Society of America.

Chemical References

• Actins
• Bni1 protein, S cerevisiae
• Cytoskeletal Proteins
• FUS1 protein, S cerevisiae
• Membrane Proteins
• Microfilament Proteins
• Peptide Initiation Factors
• Peptides
• Qc-SNARE Proteins
• RNA-Binding Proteins
• SPA2 protein, S cerevisiae
• Saccharomyces cerevisiae Proteins
• Use1 protein, S cerevisiae
• eukaryotic translation initiation factor 5A
• polyproline

Topics

• Actins (metabolism)
• Cytoskeletal Proteins (genetics, metabolism)
• Membrane Proteins (genetics, metabolism)
• Microfilament Proteins (genetics, metabolism)
• Morphogenesis
• Mutation
• Peptide Chain Elongation, Translational
• Peptide Initiation Factors (genetics, metabolism)
• Peptides (chemistry)
• Protein Structure, Tertiary
• Qc-SNARE Proteins (genetics, metabolism)
• RNA-Binding Proteins (genetics, metabolism)
• Ribosomes (metabolism)
• Saccharomyces cerevisiae (cytology, genetics)
• Saccharomyces cerevisiae Proteins (genetics, metabolism)