Regulation of cell signaling dynamics by the protein kinase-scaffold Ste5.
Mol Cell
; 30(5): 649-56, 2008 Jun 06.
Article
em En
| MEDLINE
| ID: mdl-18538663
ABSTRACT
Cell differentiation requires the ability to detect and respond appropriately to a variety of extracellular signals. Here we investigate a differentiation switch induced by changes in the concentration of a single stimulus. Yeast cells exposed to high doses of mating pheromone undergo cell division arrest. Cells at intermediate doses become elongated and divide in the direction of a pheromone gradient (chemotropic growth). Either of the pheromone-responsive MAP kinases, Fus3 and Kss1, promotes cell elongation, but only Fus3 promotes chemotropic growth. Whereas Kss1 is activated rapidly and with a graded dose-response profile, Fus3 is activated slowly and exhibits a steeper dose-response relationship (ultrasensitivity). Fus3 activity requires the scaffold protein Ste5; when binding to Ste5 is abrogated, Fus3 behaves like Kss1, and the cells no longer respond to a gradient or mate efficiently with distant partners. We propose that scaffold proteins serve to modulate the temporal and dose-response behavior of the MAP kinase.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Proteínas Quinases Ativadas por Mitógeno
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Sistema de Sinalização das MAP Quinases
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Proteínas de Saccharomyces cerevisiae
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Proteínas Adaptadoras de Transdução de Sinal
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Estados Unidos