G proteins mediate changes in cell shape by stabilizing the axis of polarity.
Upon exposure to mating pheromone, yeast cells change their form to pear-shaped shmoos. We looked at pheromone-dependent cell shape changes in mutants that are unable to orient growth during mating and unable to choose a bud site. In these double mutants, cell surface growth, secretion sites, cytoskeleton, and pheromone receptors are spread out, explaining why these cells are round. In contrast, polarity establishment proteins localize to discrete sites in these mutants. However, the location of these sites wanders. Thus, these mutants are able to initiate polarized growth but fail to maintain the location of growth sites. Our results demonstrate that stabilization of the growth axis requires positional signaling from either the pheromone receptor or specific bud site selection proteins.
Nern
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Division of Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
Arkowitz
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D002451:Cell Compartmentation; D018797:Cell Cycle Proteins / Q000235:genetics; D016764:Cell Polarity / Q000502:physiology*; D002628:Chemoreceptor Cells / Q000378:metabolism; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D019204:GTP-Binding Proteins / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors; D020962:Heterotrimeric GTP-Binding Proteins; D009024:Morphogenesis; D010675:Pheromones / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction; D020691:rab GTP-Binding Proteins / Q000235:genetics
C073594:CDC24 protein, S cerevisiae; D018797:Cell Cycle Proteins; C118981:G-protein Beta gamma; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D020662:Guanine Nucleotide Exchange Factors; D010675:Pheromones; D011518:Proto-Oncogene Proteins; D029701:Saccharomyces cerevisiae Proteins; D019204:GTP-Binding Proteins; C084013:RSR1 protein, S cerevisiae; D020962:Heterotrimeric GTP-Binding Proteins; D020691:rab GTP-Binding Proteins