title: Translational regulator RpL10p/Grc5p interacts physically and functionally with Sed1p, a dynamic component of the yeast cell surface.
abstract: Biogenesis of an active ribosome complement and a dynamic cell surface complement are two major determinants of cellular growth. In yeast, the 60S ribosomal subunit protein RpL10p/Grc5p functions during successive stages in ribosome biogenesis, specifically rRNA processing, nucle(ol)ar preribosomal subunit assembly, nucleo-cytoplasmic transport and cytoplasmic maturation of ribosomes. Here, we report that a two-hybrid screen identified yeast genes SED1, ACS2 and PLB3 as encoding proteins physically interacting with both ribosomal RpL10p/Grc5p and its human homologue hRpL10p/QMp. SED1 encodes a differentially expressed cell wall protein which is proposed to be first transiently secreted to the plasma membrane as a GPI (glycosylated derivative of phosphoinositol)-anchored form and to be then transferred to the glucan layer of the cell wall. Ectopic expression of SED1 rescues both the aberrant growth phenotype and the translation defect of grc5-1(ts) temperature-sensitive cells. Furthermore, we report that Sed1p associates with translating ribosomes suggesting a novel, cytoplasmic role for Sed1p. ACS2 encodes one of the two yeast acetyl-CoA synthases and represents a key enzyme in one of several metabolic routes to produce acetyl-CoA, which in turn is indispensable for lipid biosynthesis. PLB3 encodes a phospholipase, which is active in the breakdown of membrane lipids. Our results support the view that Grc5p/RpL10p links ribosome function to membrane turnover and cell surface biogenesis.
authors.affiliation: Department of Genetics and General Biology, Paris-Lodron University Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg.
authors.forename: Kamil
authors.initials: K
authors.lastname: Oender
authors.forename: Michael
authors.initials: M
authors.lastname: Loeffler
authors.forename: Edith
authors.initials: E
authors.lastname: Doppler
authors.forename: Michaela
authors.initials: M
authors.lastname: Eder
authors.forename: Sibylle
authors.initials: S
authors.lastname: Lach
authors.forename: Felix
authors.initials: F
authors.lastname: Heinrich
authors.forename: Thomas
authors.initials: T
authors.lastname: Karl
authors.forename: Roland
authors.initials: R
authors.lastname: Moesl
authors.forename: Harald
authors.initials: H
authors.lastname: Hundsberger
authors.forename: Torsten
authors.initials: T
authors.lastname: Klade
authors.forename: Peter
authors.initials: P
authors.lastname: Eckl
authors.forename: J Richard
authors.initials: JR
authors.lastname: Dickinson
authors.forename: Michael
authors.initials: M
authors.lastname: Breitenbach
authors.forename: Lore
authors.initials: L
authors.lastname: Koller
mesh_terms: D001483:Base Sequence; D002473:Cell Wall / Q000235:genetics / Q000502:physiology; D003066:Coenzyme A Ligases / Q000235:genetics / Q000502:physiology; D005816:Genetic Complementation Test; D008245:Lysophospholipase / Q000235:genetics / Q000502:physiology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis / Q000235:genetics / Q000502:physiology*; D012269:Ribosomal Proteins / Q000235:genetics / Q000502:physiology*; D012270:Ribosomes / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology*; D017422:Sequence Analysis, DNA; D020798:Two-Hybrid System Techniques; D015003:Yeasts / Q000235:genetics / Q000502:physiology*
chemical_list: D008562:Membrane Glycoproteins; C093333:RPL10 protein, S cerevisiae; D012269:Ribosomal Proteins; C077394:SED1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D008245:Lysophospholipase; C122013:PLB3 protein, S cerevisiae; D003066:Coenzyme A Ligases; C403665:ACSL6 protein, human