A specific protein-protein interaction accounts for the in vivo substrate selectivity of Ptp3 towards the Fus3 MAP kinase.

ABSTRACT: The mitogen-activated protein kinases (MAPKs) play critical roles in many signal transduction processes. Several MAPKs have been found in Saccharomyces cerevisiae, including Fus3 in the mating pathway and Hog1 in the osmotic-stress response pathway. Cells lacking Fus3 or Hog1 activity are deficient in mating or adaptation to osmotic shock, respectively. However, constitutive activation of either Fus3 or Hog1 is lethal. Therefore, yeast cells have to tightly regulate both the activation and inactivation of Fus3 and Hog1 MAPKs, which are controlled mainly by phosphorylation and dephosphorylation. Previous studies have shown that Fus3 activity is negatively regulated by protein tyrosine phosphatase Ptp3. In contrast, the Hog1 MAPK is mainly dephosphorylated by Ptp2 even though the two phospha

SUBMITTER: Zhan XL 

PROVIDER: S-EPMC317133 | biostudies-literature | 1999 Nov

REPOSITORIES: biostudies-literature