title: Ctk1 function is necessary for full translation initiation activity in Saccharomyces cerevisiae.
abstract: Translation is a fundamental and highly regulated cellular process. Previously, we reported that the kinase and transcription elongation factor Ctk1 increases fidelity during translation elongation in Saccharomyces cerevisiae. Here, we show that loss of Ctk1 function also affects the initiation step of translation. Translation active extracts from Ctk1-depleted cells show impaired translation activity of capped mRNA, but not mRNA reporters containing the cricket paralysis virus (CrPV) internal ribosome entry site (IRES). Furthermore, the formation of 80S initiation complexes is decreased, which is probably due to reduced subunit joining. In addition, we determined the changes in the phosphorylation pattern of a ribosome enriched fraction after depletion of Ctk1. Thus, we provide a catalogue of phosphoproteomic changes dependent on Ctk1. Taken together, our data suggest a stimulatory function of Ctk1 in 80S formation during translation initiation.
authors.affiliation: Gene Center and Department of Biochemistry, Ludwig Maximilians University of Munich, Munich, Germany Center for Integrated Protein Science Munich (CIPSM), Munich, Germany.
authors.forename: Britta
authors.initials: B
authors.lastname: Coordes
authors.affiliation: Gene Center and Department of Biochemistry, Ludwig Maximilians University of Munich, Munich, Germany Center for Integrated Protein Science Munich (CIPSM), Munich, Germany.
authors.forename: Katharina M
authors.initials: KM
authors.lastname: Brünger
authors.affiliation: Center for Integrated Protein Science Munich (CIPSM), Munich, Germany Department of Molecular Epigenetics, Helmholtz Center Munich, Munich, Germany.
authors.forename: Kaspar
authors.initials: K
authors.lastname: Burger
authors.affiliation: Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, Germany NNF Center for Protein Research, Department for Proteomics, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Boumediene
authors.initials: B
authors.lastname: Soufi
authors.affiliation: Gene Center and Department of Biochemistry, Ludwig Maximilians University of Munich, Munich, Germany Center for Integrated Protein Science Munich (CIPSM), Munich, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Horenk
authors.affiliation: Center for Integrated Protein Science Munich (CIPSM), Munich, Germany Department of Molecular Epigenetics, Helmholtz Center Munich, Munich, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Eick
authors.affiliation: Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, Germany NNF Center for Protein Research, Department for Proteomics, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jesper V
authors.initials: JV
authors.lastname: Olsen
authors.affiliation: Gene Center and Department of Biochemistry, Ludwig Maximilians University of Munich, Munich, Germany Center for Integrated Protein Science Munich (CIPSM), Munich, Germany Institute of Biochemistry, Justus Liebig University Gießen, Gießen, Germany katja.straesser@chemie.bio.uni-giessen.de.
authors.forename: Katja
authors.initials: K
authors.lastname: Sträßer
mesh_terms: D010442:Peptide Chain Initiation, Translational; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D054657:Ribosome Subunits / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C118305:CTDK-I protein complex, S cerevisiae; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases