title: A Cellular System for Spatial Signal Decoding in Chemical Gradients.
abstract: Directional cell growth requires that cells read and interpret shallow chemical gradients, but how the gradient directional information is identified remains elusive. We use single-cell analysis and mathematical modeling to define the cellular gradient decoding network in yeast. Our results demonstrate that the spatial information of the gradient signal is read locally within the polarity site complex using double-positive feedback between the GTPase Cdc42 and trafficking of the receptor Ste2. Spatial decoding critically depends on low Cdc42 activity, which is maintained by the MAPK Fus3 through sequestration of the Cdc42 activator Cdc24. Deregulated Cdc42 or Ste2 trafficking prevents gradient decoding and leads to mis-oriented growth. Our work discovers how a conserved set of components assembles a network integrating signal intensity and directionality to decode the spatial information contained in chemical gradients.
authors.affiliation: Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland. Electronic address: bjoern.hegemann@bc.biol.ethz.ch.
authors.forename: Björn
authors.initials: B
authors.lastname: Hegemann
authors.affiliation: Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland; Automatic Control Laboratory, ETH Zurich, Physikstrasse 3, 8092 Zürich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Unger
authors.affiliation: Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland.
authors.forename: Sung Sik
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Stoffel-Studer
authors.affiliation: Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland.
authors.forename: Jasmin
authors.initials: J
authors.lastname: van den Heuvel
authors.affiliation: Department of Fundamental Microbiology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland.
authors.forename: Serge
authors.initials: S
authors.lastname: Pelet
authors.affiliation: Automatic Control Laboratory, ETH Zurich, Physikstrasse 3, 8092 Zürich, Switzerland; Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Rundeturmstrasse 12, 64283 Darmstadt, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Koeppl
authors.affiliation: Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland. Electronic address: matthias.peter@bc.biol.ethz.ch.
authors.forename: Matthias
authors.initials: M
authors.lastname: Peter
mesh_terms: D016764:Cell Polarity / Q000502:physiology*; D002633:Chemotaxis; D007091:Image Processing, Computer-Assisted; D015151:Immunoblotting; D046210:Microfluidic Analytical Techniques; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D008962:Models, Theoretical; D011485:Protein Binding; D021381:Protein Transport; D051964:Receptors, Mating Factor / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D059010:Single-Cell Analysis / Q000379:methods; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*
chemical_list: D051964:Receptors, Mating Factor; C498031:STE2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C075580:FUS3 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae