title: Role of Polarized G Protein Signaling in Tracking Pheromone Gradients.
abstract: Yeast cells track gradients of pheromones to locate mating partners. Intuition suggests that uniform distribution of pheromone receptors over the cell surface would yield optimal gradient sensing. However, yeast cells display polarized receptors. The benefit of such polarization was unknown. During gradient tracking, cell growth is directed by a patch of polarity regulators that wanders around the cortex. Patch movement is sensitive to pheromone dose, with wandering reduced on the up-gradient side of the cell, resulting in net growth in that direction. Mathematical modeling suggests that active receptors and associated G proteins lag behind the polarity patch and act as an effective drag on patch movement. In vivo, the polarity patch is trailed by a G protein-rich domain, and this polarized distribution of G proteins is required to constrain patch wandering. Our findings explain why G protein polarization is beneficial and illuminate a novel mechanism for gradient tracking.
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Allison W
authors.initials: AW
authors.lastname: McClure
authors.affiliation: Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Minakova
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Jayme M
authors.initials: JM
authors.lastname: Dyer
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Trevin R
authors.initials: TR
authors.lastname: Zyla
authors.affiliation: Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Electronic address: timothy_elston@med.unc.edu.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Elston
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA. Electronic address: daniel.lew@duke.edu.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Lew
mesh_terms: D002462:Cell Membrane / Q000378:metabolism*; D016764:Cell Polarity / Q000502:physiology*; D002633:Chemotaxis; D003198:Computer Simulation; D004705:Endocytosis / Q000502:physiology; D005089:Exocytosis / Q000502:physiology; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D010675:Pheromones / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D010675:Pheromones; D029701:Saccharomyces cerevisiae Proteins; D019204:GTP-Binding Proteins