ABI2, a second protein phosphatase 2C involved in abscisic acid signal transduction in Arabidopsis

FEBS Lett. 1998 Jan 16;421(3):185-90. doi: 10.1016/s0014-5793(97)01558-5.


The abi2-1 (abscisic acid insensitive) mutant of Arabidopsis thaliana shows abscisic acid (ABA) insensitivity with respect to seed germination and vegetative ABA responses. We identified the ABI2 gene by a combination of positional mapping and homology to ABI1. The ABI2 protein shows 80% amino acid sequence identity to ABI1, a protein phosphatase 2C (PP2C) involved in ABA signaling. The mutation that confers the abi2-1 phenotype is equivalent to the mutation previously identified in abi1-1 and the resulting Gly168Asp abi2 protein shows a reduced PP2C activity. Thus, a pair of highly homologous PP2Cs regulate ABA signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / metabolism*
  • Amino Acid Sequence
  • Arabidopsis / enzymology
  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins*
  • Chromosome Mapping
  • Cloning, Molecular
  • Molecular Sequence Data
  • Phosphoprotein Phosphatases / genetics*
  • Phosphoprotein Phosphatases / metabolism
  • Protein Phosphatase 2
  • Protein Phosphatase 2C
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Signal Transduction*


  • Arabidopsis Proteins
  • Saccharomyces cerevisiae Proteins
  • Abscisic Acid
  • ABI1 protein, Arabidopsis
  • ABI2 protein, Arabidopsis
  • PTC1 protein, S cerevisiae
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 2
  • Protein Phosphatase 2C

Associated data

  • GENBANK/Y11840