MP2C, a plant protein phosphatase 2C, functions as a negative regulator of mitogen-activated protein kinase pathways in yeast and plants

Proc Natl Acad Sci U S A. 1998 Feb 17;95(4):1938-43. doi: 10.1073/pnas.95.4.1938.

Abstract

By interference of the yeast pheromone mitogen-activated protein kinase (MAPK) pathway with an alfalfa cDNA expression library, we have isolated the MP2C gene encoding a functional protein phosphatase type 2C. Epistasis analysis in yeast indicated that the molecular target of the MP2C phosphatase is Ste11, a MAPK kinase kinase that is a central regulator of the pheromone and osmosensing pathways. In plants, MP2C functions as a negative regulator of the stress-activated MAPK (SAMK) pathway that is activated by cold, drought, touch, and wounding. Although activation of the SAMK pathway occurs by a posttranslational mechanism, de novo transcription and translation of protein factor(s) are necessary for its inactivation. MP2C is likely to be this or one of these factors, because wound-induced activation of SAMK is followed by MP2C gene expression and recombinant glutathione S-transferase-MP2C is able to inactivate extracts containing wound-induced SAMK. Wound-induced MP2C expression is a transient event and correlates with the refractory period, i.e., the time when restimulation of the SAMK pathway is not possible by a second stimulation. These data suggest that MP2C is part of a negative feedback mechanism that is responsible for resetting the SAMK cascade in plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Fungal Proteins / metabolism
  • Fungal Proteins / physiology*
  • Humans
  • MAP Kinase Kinase Kinases / physiology*
  • Molecular Sequence Data
  • Phosphoprotein Phosphatases / metabolism*
  • Plant Proteins / metabolism
  • Protein Phosphatase 2
  • Protein Phosphatase 2C
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins*
  • Schizosaccharomyces pombe Proteins*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Signal Transduction
  • Stress, Physiological / metabolism
  • Transcription Factors*
  • Wound Healing

Substances

  • Fungal Proteins
  • Plant Proteins
  • Saccharomyces cerevisiae Proteins
  • Schizosaccharomyces pombe Proteins
  • Transcription Factors
  • ste11 protein, S pombe
  • Calcium-Calmodulin-Dependent Protein Kinases
  • MAP Kinase Kinase Kinases
  • Ste11 protein, S cerevisiae
  • PPM1A protein, human
  • PPM1B protein, human
  • PPM1G protein, human
  • PTC1 protein, S cerevisiae
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 2
  • Protein Phosphatase 2C

Associated data

  • GENBANK/Y11607