title: Interaction proteomics suggests a new role for the Tfs1 protein in yeast.
abstract: The PEBP (phosphatidylethanolamine-binding protein) family is a large group of proteins whose human member, hPEBP1, has been shown to play multiple functions, influencing intracellular signaling cascades, cell cycle regulation, neurodegenerative processes, and reproduction. It also acts, by an unknown mechanism, as a metastasis suppressor in a number of cancers. A more complete understanding of its biological role is thus necessary. As the yeast Saccharomyces cerevisiae is a powerful and easy to handle model organism, we focused on Tfs1p, the yeast ortholog of hPEBP1. In a previous study based on a two-hybrid approach, we showed that Tfs1p interacts and inhibits Ira2p, a GTPase Activating Protein (GAP) of the small GTPase Ras. To further characterize the molecular functions of Tfs1p, we undertook the identification of protein complexes formed around Tfs1p using a targeted proteomics approach. Complexed proteins were purified by tandem-affinity, cleaved with trypsin, and identified by nanoflow liquid chromatography coupled with tandem mass spectrometry. Overall, 14 new interactors were identified, including several proteins involved in intermediate metabolism. We confirmed by co-immunoprecipitation that Tfs1p interacts with Glo3p, a GAP for Arf GTPases belonging to the Ras superfamily of small GTPases, indicating that Tfs1p may be involved in the regulation of another GAP. We similarly confirmed the binding of Tfs1p with the metabolic enzymes Idp1p and Pro1p. Integration of these results with known functional partners of Tfs1p shows that two subnetworks meet through the Tfs1p node, suggesting that it may act as a bridge between cell signaling and intermediate metabolism in yeast.
authors.affiliation: Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique, UPR 4301 , affiliated to the University of Orléans, rue Charles Sadron, 45071 Orléans cedex 2.
authors.forename: Martine
authors.initials: M
authors.lastname: Beaufour
authors.forename: Fabienne
authors.initials: F
authors.lastname: Godin
authors.forename: Béatrice
authors.initials: B
authors.lastname: Vallée
authors.forename: Martine
authors.initials: M
authors.lastname: Cadene
authors.forename: Hélène
authors.initials: H
authors.lastname: Bénédetti
mesh_terms: D002352:Carrier Proteins / Q000302:isolation & purification / Q000502:physiology*; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins; D053858:Metabolic Networks and Pathways; D025941:Protein Interaction Mapping; D060066:Protein Interaction Maps; D040901:Proteomics; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000302:isolation & purification / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D029701:Saccharomyces cerevisiae Proteins; C492432:Tfs1 protein, S cerevisiae