Specificity of MAP kinase signaling in yeast differentiation involves transient versus sustained MAPK activation.
Signals transmitted by common components often elicit distinct (yet appropriate) outcomes. In yeast, two developmental options-mating and invasive growth-are both regulated by the same MAP kinase cascade. Specificity has been thought to result from specialized roles for the two MAP kinases, Kss1 and Fus3, and because Fus3 prevents Kss1 from gaining access to the mating pathway. Kss1 has been thought to participate in mating only when Fus3 is absent. Instead, we show that Kss1 is rapidly phosphorylated and potently activated by mating pheromone in wild-type cells, and that this is required for normal pheromone-induced gene expression. Signal identity is apparently maintained because active Fus3 limits the extent of Kss1 activation, thereby preventing inappropriate signal crossover.
Sabbagh
W
W
Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA.
Flatauer
L J
LJ
Bardwell
A J
AJ
Bardwell
L
L
D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D017930:Genes, Reporter / Q000235:genetics; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000502:physiology*; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins
D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; C075580:FUS3 protein, S cerevisiae; C541984:KSS1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases; C067018:Ste11 protein, S cerevisiae; D020929:Mitogen-Activated Protein Kinase Kinases; C119844:STE7 protein, S cerevisiae