title: Yeast dynamically modify their environment to achieve better mating efficiency.
abstract: The maintenance and detection of signaling gradients are critical for proper development and cell migration. In single-cell organisms, gradient detection allows cells to orient toward a distant mating partner or nutrient source. Budding yeast expand their growth toward mating pheromone gradients through a process known as chemotropic growth. MATα cells secrete α-factor pheromone that stimulates chemotropism and mating differentiation in MATa cells and vice versa. Paradoxically, MATa cells secrete Bar1, a protease that degrades α-factor and that attenuates the mating response, yet is also required for efficient mating. We observed that MATa cells avoid each other during chemotropic growth. To explore this behavior, we developed a computational platform to simulate chemotropic growth. Our simulations indicated that the release of Bar1 enabled individual MATa cells to act as α-factor sinks. The simulations suggested that the resultant local reshaping of pheromone concentration created gradients that were directed away from neighboring MATa cells (self-avoidance) and that were increasingly amplified toward partners of the opposite sex during elongation. The behavior of Bar1-deficient cells in gradient chambers and mating assays supported these predictions from the simulations. Thus, budding yeast dynamically remodel their environment to ensure productive responses to an external stimulus and avoid nonproductive cell-cell interactions.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Meng
authors.initials: M
authors.lastname: Jin
authors.forename: Beverly
authors.initials: B
authors.lastname: Errede
authors.forename: Marcelo
authors.initials: M
authors.lastname: Behar
authors.forename: Will
authors.initials: W
authors.lastname: Mather
authors.forename: Sujata
authors.initials: S
authors.lastname: Nayak
authors.forename: Jeff
authors.initials: J
authors.lastname: Hasty
authors.forename: Henrik G
authors.initials: HG
authors.lastname: Dohlman
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Elston
mesh_terms: D016282:Aspartic Acid Endopeptidases / Q000235:genetics / Q000378:metabolism; D000072235:Mating Factor; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D059748:Proteolysis; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D010455:Peptides; D029701:Saccharomyces cerevisiae Proteins; D000072235:Mating Factor; D016282:Aspartic Acid Endopeptidases; C491999:BAR1 protein, S cerevisiae