title: Polarity establishment requires localized activation of Cdc42.
abstract: Establishment of cell polarity in animal and fungal cells involves localization of the conserved Rho-family guanosine triphosphatase, Cdc42, to the cortical region destined to become the "front" of the cell. The high local concentration of active Cdc42 promotes cytoskeletal polarization through various effectors. Cdc42 accumulation at the front is thought to involve positive feedback, and studies in the budding yeast Saccharomyces cerevisiae have suggested distinct positive feedback mechanisms. One class of mechanisms involves localized activation of Cdc42 at the front, whereas another class involves localized delivery of Cdc42 to the front. Here we show that Cdc42 activation must be localized for successful polarity establishment, supporting local activation rather than local delivery as the dominant mechanism in this system.
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Woods
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710.
authors.forename: Chun-Chen
authors.initials: CC
authors.lastname: Kuo
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710.
authors.forename: Chi-Fang
authors.initials: CF
authors.lastname: Wu
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710.
authors.forename: Trevin R
authors.initials: TR
authors.lastname: Zyla
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710 daniel.lew@duke.edu.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Lew
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D016764:Cell Polarity; D004789:Enzyme Activation; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae / Q000502:physiology*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C073594:CDC24 protein, S cerevisiae; D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D029701:Saccharomyces cerevisiae Proteins; C073129:BEM1 protein, S cerevisiae; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae