| Title: | Mating yeast cells use an intrinsic polarity site to assemble a pheromone-gradient tracking machine |
| Author(s): | Wang X; Tian W; Banh BT; Statler BM; Liang J; Stone DE; |
| Address: | "Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL. Department of Bioengineering, University of Illinois at Chicago, Chicago, IL. Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL dstone@uic.edu" |
| ISSN/ISBN: | 1540-8140 (Electronic) 0021-9525 (Print) 0021-9525 (Linking) |
| Abstract: | "The mating of budding yeast depends on chemotropism, a fundamental cellular process. The two yeast mating types secrete peptide pheromones that bind to GPCRs on cells of the opposite type. Cells find and contact a partner by determining the direction of the pheromone source and polarizing their growth toward it. Actin-directed secretion to the chemotropic growth site (CS) generates a mating projection. When pheromone-stimulated cells are unable to sense a gradient, they form mating projections where they would have budded in the next cell cycle, at a position called the default polarity site (DS). Numerous models have been proposed to explain yeast gradient sensing, but none address how cells reliably switch from the intrinsically determined DS to the gradient-aligned CS, despite a weak spatial signal. Here we demonstrate that, in mating cells, the initially uniform receptor and G protein first polarize to the DS, then redistribute along the plasma membrane until they reach the CS. Our data indicate that signaling, polarity, and trafficking proteins localize to the DS during assembly of what we call the gradient tracking machine (GTM). Differential activation of the receptor triggers feedback mechanisms that bias exocytosis upgradient and endocytosis downgradient, thus enabling redistribution of the GTM toward the pheromone source. The GTM stabilizes when the receptor peak centers at the CS and the endocytic machinery surrounds it. A computational model simulates GTM tracking and stabilization and correctly predicts that its assembly at a single site contributes to mating fidelity" |
| Keywords: | *Cell Polarity Pheromones/*metabolism Saccharomyces cerevisiae/*cytology/*metabolism; |
| Notes: | "MedlineWang, Xin Tian, Wei Banh, Bryan T Statler, Bethanie-Michelle Liang, Jie Stone, David E eng R01 CA204962/CA/NCI NIH HHS/ R21 AI126308/AI/NIAID NIH HHS/ R35 GM127084/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural Research Support, U.S. Gov't, Non-P.H.S. 2019/10/02 J Cell Biol. 2019 Nov 4; 218(11):3730-3752. doi: 10.1083/jcb.201901155. Epub 2019 Sep 30" |
