A hypermorphic mutation in the protein phosphatase 2C HAB1 strongly affects ABA signaling in Arabidopsis

FEBS Lett. 2006 Aug 21;580(19):4691-6. doi: 10.1016/j.febslet.2006.07.047. Epub 2006 Jul 24.


Protein phosphatases of the 2C family (PP2C) function in the regulation of several signaling pathways from prokaryotes to eukaryotes. In Arabidopsis thaliana, the HAB1 PP2C is a negative regulator of the stress hormone abscisic acid (ABA) signaling. Here, we show that plants expressing a mutant form of HAB1 in which Gly246 was mutated to Asp (G246D) display strong ABA insensitive phenotypes. Our results indicate that the G246D mutation has a hypermorphic rather than a dominant negative effect. The data suggest that this mutation localized in a conserved motif in the PP2C catalytic domain could be used in other PP2Cs to reveal their biological functions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Abscisic Acid / metabolism*
  • Amino Acid Sequence
  • Arabidopsis / enzymology
  • Arabidopsis / genetics*
  • Base Sequence
  • Molecular Sequence Data
  • Phosphoprotein Phosphatases / chemistry
  • Phosphoprotein Phosphatases / genetics
  • Phosphoprotein Phosphatases / metabolism*
  • Point Mutation*
  • Protein Phosphatase 2C
  • Sequence Homology, Amino Acid
  • Signal Transduction*


  • Abscisic Acid
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 2C