title: The Saccharomyces homolog of mammalian RACK1, Cpc2/Asc1p, is required for FLO11-dependent adhesive growth and dimorphism.
abstract: Nutrient starvation results in the interaction of Saccharomyces cerevisiae cells with each other and with surfaces. Adhesive growth requires the expression of the FLO11 gene regulated by the Ras/cAMP/cAMP-dependent protein kinase, the Kss1p/MAPK, and the Gcn4p/general amino acid control pathway, respectively. Proteomics two-dimensional DIGE experiments revealed post-transcriptionally regulated proteins in response to amino acid starvation including the ribosomal protein Cpc2p/Asc1p. This putative translational regulator is highly conserved throughout the eukaryotic kingdom and orthologous to mammalian RACK1. Deletion of CPC2/ASC1 abolished amino acid starvation-induced adhesive growth and impaired basal expression of FLO11 and its activation upon starvation in haploid cells. In addition, the diploid Flo11p-dependent pseudohyphal growth during nitrogen limitation was CPC2/ASC1-dependent. A more detailed analysis revealed that a CPC2/ASC1 deletion caused increased sensitivity to cell wall drugs suggesting that the gene is required for general cell wall integrity. Phosphoproteome and Western hybridization data indicate that Cpc2p/Asc1p affected the phosphorylation of the translational initiation factors eIF2 alpha and eIF4A and the ribosome-associated complex RAC. A crucial role of Cpc2p/Asc1p at the ribosomal interface coordinating signal transduction, translation initiation, and transcription factor formation was corroborated.
authors: Institute of Microbiology and Genetics, Georg August University, D-37077 Göttingen, Germany.
authors: Oliver
authors: O
authors: Valerius
authors: Malte
authors: M
authors: Kleinschmidt
authors: Nicole
authors: N
authors: Rachfall
authors: Florian
authors: F
authors: Schulze
authors: Sarai
authors: S
authors: López Marín
authors: Michael
authors: M
authors: Hoppert
authors: Katrin
authors: K
authors: Streckfuss-Bömeke
authors: Claudia
authors: C
authors: Fischer
authors: Gerhard H
authors: GH
authors: Braus
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000172:deficiency; D002448:Cell Adhesion / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D015852:Eukaryotic Initiation Factor-2 / Q000378:metabolism; D019204:GTP-Binding Proteins; D017353:Gene Deletion; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010448:Peptide Initiation Factors / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis; D020543:Proteome / Q000032:analysis; D040901:Proteomics; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D012727:Sex Characteristics
chemical_list: C111825:ASC1 protein, S cerevisiae; D048868:Adaptor Proteins, Signal Transducing; D000596:Amino Acids; D015852:Eukaryotic Initiation Factor-2; C110690:FLO11 protein, S cerevisiae; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010448:Peptide Initiation Factors; D010750:Phosphoproteins; D020543:Proteome; D029701:Saccharomyces cerevisiae Proteins; C075833:eIF-4; D019204:GTP-Binding Proteins