title: 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.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universitat de València, E-46100 Burjassot, Valencia, Spain.
authors.forename: Tianlu
authors.initials: T
authors.lastname: Li
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas, Centro Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain.
authors.forename: Borja
authors.initials: B
authors.lastname: Belda-Palazón
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas, Centro Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain paula.alepuz@uv.es aferrando@ibmcp.upv.es.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ferrando
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universitat de València, E-46100 Burjassot, Valencia, Spain paula.alepuz@uv.es aferrando@ibmcp.upv.es.
authors.forename: Paula
authors.initials: P
authors.lastname: Alepuz
mesh_terms: D000199:Actins / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D009024:Morphogenesis; D009154:Mutation; D010441:Peptide Chain Elongation, Translational; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D050767:Qc-SNARE Proteins / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D000097574:Eukaryotic Translation Initiation Factor 5A
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D010448:Peptide Initiation Factors; D010455:Peptides; D050767:Qc-SNARE Proteins; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D000097574:Eukaryotic Translation Initiation Factor 5A; C105191:Bni1 protein, S cerevisiae; C490024:FUS1 protein, S cerevisiae; C065889:SPA2 protein, S cerevisiae; C477343:Use1 protein, S cerevisiae; C011083:polyproline
keywords: eIF5A; formins; mating; polarized growth; translation