title: Electrochemical regulation of budding yeast polarity.
abstract: Cells are naturally surrounded by organized electrical signals in the form of local ion fluxes, membrane potential, and electric fields (EFs) at their surface. Although the contribution of electrochemical elements to cell polarity and migration is beginning to be appreciated, underlying mechanisms are not known. Here we show that an exogenous EF can orient cell polarization in budding yeast (Saccharomyces cerevisiae) cells, directing the growth of mating projections towards sites of hyperpolarized membrane potential, while directing bud emergence in the opposite direction, towards sites of depolarized potential. Using an optogenetic approach, we demonstrate that a local change in membrane potential triggered by light is sufficient to direct cell polarization. Screens for mutants with altered EF responses identify genes involved in transducing electrochemical signals to the polarity machinery. Membrane potential, which is regulated by the potassium transporter Trk1p, is required for polarity orientation during mating and EF response. Membrane potential may regulate membrane charges through negatively charged phosphatidylserines (PSs), which act to position the Cdc42p-based polarity machinery. These studies thus define an electrochemical pathway that directs the orientation of cell polarization.
authors.affiliation: Institut Jacques Monod, UMR7592 CNRS, Paris, France.
authors.forename: Armin
authors.initials: A
authors.lastname: Haupt
authors.affiliation: Institut Jacques Monod, UMR7592 CNRS, Paris, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Campetelli
authors.affiliation: Institut Jacques Monod, UMR7592 CNRS, Paris, France.
authors.forename: Daria
authors.initials: D
authors.lastname: Bonazzi
authors.affiliation: Institut Curie, UMR 144 CNRS/IC, Paris, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Piel
authors.affiliation: Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, New York, United States of America.
authors.forename: Fred
authors.initials: F
authors.lastname: Chang
authors.affiliation: Institut Jacques Monod, UMR7592 CNRS, Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Minc
mesh_terms: D027682:Cation Transport Proteins / Q000378:metabolism; D016764:Cell Polarity; D004560:Electricity; D004563:Electrochemistry; D008055:Lipids / Q000494:pharmacology; D008564:Membrane Potentials; D008954:Models, Biological; D062308:Optogenetics; D010718:Phosphatidylserines / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D004718:Saccharomycetales / Q000166:cytology* / Q000378:metabolism; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae / Q000378:metabolism
chemical_list: D027682:Cation Transport Proteins; D008055:Lipids; D010718:Phosphatidylserines; D029701:Saccharomyces cerevisiae Proteins; C068664:TRK1 protein, S cerevisiae; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae