Title: | RGS proteins and septins cooperate to promote chemotropism by regulating polar cap mobility |
Author(s): | Kelley JB; Dixit G; Sheetz JB; Venkatapurapu SP; Elston TC; Dohlman HG; |
Address: | "Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 3046 Genetic Medicine Building, Campus Box 7260, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 4009 Genetic Medicine Building, Campus Box 7365, Chapel Hill, NC 27599, USA. Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 3046 Genetic Medicine Building, Campus Box 7260, Chapel Hill, NC 27599, USA. Department of Pharmacology, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 4009 Genetic Medicine Building, Campus Box 7365, Chapel Hill, NC 27599, USA; Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 4092 Genetic Medicine Building, Campus Box 7365, Chapel Hill, NC 27599, USA. Department of Pharmacology, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 4009 Genetic Medicine Building, Campus Box 7365, Chapel Hill, NC 27599, USA. Electronic address: timothy_elston@med.unc.edu. Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 3046 Genetic Medicine Building, Campus Box 7260, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 4009 Genetic Medicine Building, Campus Box 7365, Chapel Hill, NC 27599, USA. Electronic address: henrik_dohlman@med.unc.edu" |
DOI: | 10.1016/j.cub.2014.11.047 |
ISSN/ISBN: | 1879-0445 (Electronic) 0960-9822 (Print) 0960-9822 (Linking) |
Abstract: | "BACKGROUND: Septins are well known to form a boundary between mother and daughter cells in mitosis, but their role in other morphogenic states is poorly understood. RESULTS: Using microfluidics and live-cell microscopy, coupled with new computational methods for image analysis, we investigated septin function during pheromone-dependent chemotropic growth in yeast. We show that septins colocalize with the regulator of G protein signaling (RGS) Sst2, a GTPase-activating protein that dampens pheromone receptor signaling. We show further that the septin structure surrounds the polar cap, ensuring that cell growth is directed toward the source of pheromone. When RGS activity is abrogated, septins are partially disorganized. Under these circumstances, the polar cap travels toward septin structures and away from sites of exocytosis, resulting in a loss of gradient tracking. CONCLUSIONS: Septin organization is dependent on RGS protein activity. When assembled correctly, septins promote turning of the polar cap and proper tracking of a pheromone gradient" |
Keywords: | "Cell Polarity/*physiology GTPase-Activating Proteins/metabolism Image Processing, Computer-Assisted Microfluidic Analytical Techniques Models, Biological RGS Proteins/*metabolism Receptors, Pheromone/metabolism Saccharomyces cerevisiae/*growth & developme;" |
Notes: | "MedlineKelley, Joshua B Dixit, Gauri Sheetz, Joshua B Venkatapurapu, Sai Phanindra Elston, Timothy C Dohlman, Henrik G eng GM079271/GM/NIGMS NIH HHS/ R01 GM079271/GM/NIGMS NIH HHS/ R01 GM080739/GM/NIGMS NIH HHS/ GM103870/GM/NIGMS NIH HHS/ R01 GM103870/GM/NIGMS NIH HHS/ GM080739/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't England 2015/01/21 Curr Biol. 2015 Feb 2; 25(3):275-285. doi: 10.1016/j.cub.2014.11.047. Epub 2015 Jan 15" |