Ratiometric GPCR signaling enables directional sensing in yeast.

Autor: Henderson NT; Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America., Pablo M; Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.; Program in Molecular and Cellular Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America., Ghose D; Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America., Clark-Cotton MR; Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America., Zyla TR; Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America., Nolen J; Department of Mathematics, Duke University, Durham, North Carolina, United States of America., Elston TC; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America., Lew DJ; Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America.
Jazyk: angličtina
Zdroj: PLoS biology [PLoS Biol] 2019 Oct 17; Vol. 17 (10), pp. e3000484. Date of Electronic Publication: 2019 Oct 17 (Print Publication: 2019).
DOI: 10.1371/journal.pbio.3000484
Abstrakt: Accurate detection of extracellular chemical gradients is essential for many cellular behaviors. Gradient sensing is challenging for small cells, which can experience little difference in ligand concentrations on the up-gradient and down-gradient sides of the cell. Nevertheless, the tiny cells of the yeast Saccharomyces cerevisiae reliably decode gradients of extracellular pheromones to find their mates. By imaging the behavior of polarity factors and pheromone receptors, we quantified the accuracy of initial polarization during mating encounters. We found that cells bias the orientation of initial polarity up-gradient, even though they have unevenly distributed receptors. Uneven receptor density means that the gradient of ligand-bound receptors does not accurately reflect the external pheromone gradient. Nevertheless, yeast cells appear to avoid being misled by responding to the fraction of occupied receptors rather than simply the concentration of ligand-bound receptors. Such ratiometric sensing also serves to amplify the gradient of active G protein. However, this process is quite error-prone, and initial errors are corrected during a subsequent indecisive phase in which polarity clusters exhibit erratic mobile behavior.
Competing Interests: The authors have declared that no competing interests exist.
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje