showing 2 related works from this author
Response of the Saccharomyces cerevisiae Mpk1 Mitogen-Activated Protein Kinase Pathway to Increases in Internal Turgor Pressure Caused by Loss of Ppz…
2004
ABSTRACT The Mpk1 pathway of Saccharomyces cerevisiae is a key determinant of cell wall integrity. A genetic link between the Mpk1 kinase and the Ppz phosphatases has been reported, but the nature of this connection was unclear. Recently, the Ppz phosphatases were shown to be regulators of K + and pH homeostasis. Here, we demonstrate that Ppz-deficient strains display increased steady-state K + levels and sensitivity to increased KCl concentrations. Given these observations and the fact that K + is the major determinant of intracellular turgor pressure, we reasoned that the connection between PPZ1 and - 2 and MPK1 was due to the combination of increased internal turgor pressure in Ppz-defic…
A novel target of lithium therapy.
2000
Phosphatases converting 3'-phosphoadenosine 5'-phosphate (PAP) into adenosine 5'-phosphate are of fundamental importance in living cells as the accumulation of PAP is toxic to several cellular systems. These enzymes are lithium-sensitive and we have characterized a human PAP phosphatase as a potential target of lithium therapy. A cDNA encoding a human enzyme was identified by data base screening, expressed in Escherichia coli and the 33 kDa protein purified to homogeneity. The enzyme exhibits high affinity for PAP (K(m)1 microM) and is sensitive to subtherapeutic concentrations of lithium (IC(50)=0.3 mM). The human enzyme also hydrolyzes inositol-1, 4-bisphosphate with high affinity (K(m)=0…