title: Symmetry breaking in the life cycle of the budding yeast.
abstract: The budding yeast Saccharomyces cerevisiae has been an invaluable model system for the study of the establishment of cellular asymmetry and growth polarity in response to specific physiological cues. A large body of experimental observations has shown that yeast cells are able to break symmetry and establish polarity through two coupled and partially redundant intrinsic mechanisms, even in the absence of any pre-existing external asymmetry. One of these mechanisms is dependent upon interplay between the actin cytoskeleton and the Rho family GTPase Cdc42, whereas the other relies on a Cdc42 GTPase signaling network. Integral to these mechanisms appear to be positive feedback loops capable of amplifying small and stochastic asymmetries. Spatial cues, such as bud scars and pheromone gradients, orient cell polarity by modulating the regulation of the Cdc42 GTPase cycle, thereby biasing the site of asymmetry amplification.
authors.affiliation: Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, Missouri 64110, USA. rli@stowers.org
authors.forename: Brian D
authors.initials: BD
authors.lastname: Slaughter
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Smith
authors.forename: Rong
authors.initials: R
authors.lastname: Li
mesh_terms: D000199:Actins / Q000378:metabolism; D016764:Cell Polarity / Q000502:physiology; D015966:Gene Expression Regulation, Fungal; D008954:Models, Biological; D011003:Ploidies; D004718:Saccharomycetales / Q000235:genetics* / Q000502:physiology*; D049490:Systems Biology; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism
chemical_list: D000199:Actins; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae; D020741:rho GTP-Binding Proteins