title: The highly conserved eukaryotic DRG factors are required for efficient translation in a manner redundant with the putative RNA helicase Slh1.
abstract: Eukaryotic and archaeal DRG factors are highly conserved proteins with characteristic GTPase motifs. This suggests their implication in a central biological process, which has so far escaped detection. We show here that the two Saccharomyces cerevisiae DRGs form distinct complexes, RBG1 and RBG2, and that the former co-fractionate with translating ribosomes. A genetic screen for triple synthetic interaction demonstrates that yeast DRGs have redundant function with Slh1, a putative RNA helicase also associating with translating ribosomes. Translation and cell growth are severely impaired in a triple mutant lacking both yeast DRGs and Slh1, but not in double mutants. This new genetic assay allowed us to characterize the roles of conserved motifs present in these proteins for efficient translation and/or association with ribosomes. Altogether, our results demonstrate for the first time a direct role of the highly conserved DRG factors in translation and indicate that this function is redundantly shared by three factors. Furthermore, our data suggest that important cellular processes are highly buffered against external perturbation and, consequently, that redundantly acting factors may escape detection in current high-throughput binary genetic interaction screens.
authors.affiliation: Equipe Labellisée La Ligue, CGM, CNRS FRE3144, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, Univ Paris-Sud, Orsay F-91405, France.
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Daugeron
authors.forename: Manoël
authors.initials: M
authors.lastname: Prouteau
authors.forename: François
authors.initials: F
authors.lastname: Lacroute
authors.forename: Bertrand
authors.initials: B
authors.lastname: Séraphin
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D017124:Conserved Sequence; D053487:DEAD-box RNA Helicases / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D009154:Mutation; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; C483478:Gir2 protein, S cerevisiae; C544704:Rbg1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C078418:developmentally regulated GTP-binding protein; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; C558799:Rbg2 protein, S cerevisiae; C432685:SLH1 protein, S cerevisiae; D053487:DEAD-box RNA Helicases