Control of MAPK specificity by feedback phosphorylation of shared adaptor protein Ste50.
Many different signaling pathways share common components but nevertheless invoke distinct physiological responses. In yeast, the adaptor protein Ste50 functions in multiple mitogen-activated protein (MAP) kinase pathways, each with unique dynamical and developmental properties. Although Kss1 activity is sustained and promotes invasive growth, Hog1 activity is transient and promotes cell adaptation to osmotic stress. Here we show that osmotic stress activates Kss1 as well as Hog1. We show further that Hog1 phosphorylates Ste50 and that phosphorylation of Ste50 limits the duration of Kss1 activation and prevents invasive growth under high osmolarity growth conditions. Thus feedback regulation of a shared component can restrict the activity of a competing MAP kinase to ensure signal fidelity.
Department of Biochemistry, University of North Carolina, Chapel Hill, North Carolina 27599-7260, USA.
Nan
N
Hao
Yaxue
Y
Zeng
Timothy C
TC
Elston
Henrik G
HG
Dohlman
D001665:Binding Sites; D025461:Feedback, Physiological; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D009154:Mutation; D009995:Osmosis; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000378:metabolism* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D013997:Time Factors
C079506:STE50 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C075580:FUS3 protein, S cerevisiae; C088589:HOG1 protein, S cerevisiae; C541984:KSS1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases