Modulation of an RNA-binding protein by abscisic-acid-activated protein kinase

Nature. 2002 Aug 15;418(6899):793-7. doi: 10.1038/nature00936.


Protein kinases are involved in stress signalling in both plant and animal systems. The hormone abscisic acid mediates the responses of plants to stresses such as drought, salinity and cold. Abscisic-acid-activated protein kinase (AAPK -- found in guard cells, which control stomatal pores -- has been shown to regulate plasma membrane ion channels. Here we show that AAPK-interacting protein 1 (AKIP1), with sequence homology to heterogeneous nuclear RNA-binding protein A/B, is a substrate of AAPK. AAPK-dependent phosphorylation is required for the interaction of AKIP1 with messenger RNA that encodes dehydrin, a protein implicated in cell protection under stress conditions. AAPK and AKIP1 are present in the guard-cell nucleus, and in vivo treatment of such cells with abscisic acid enhances the partitioning of AKIP1 into subnuclear foci which are reminiscent of nuclear speckles. These results show that phosphorylation-regulated RNA target discrimination by heterogeneous nuclear RNA-binding proteins may be a general phenomenon in eukaryotes, and implicate a plant hormone in the regulation of protein dynamics during rapid subnuclear reorganization.

Publication types

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

MeSH terms

  • Abscisic Acid / pharmacology*
  • Amino Acid Sequence
  • Cell Nucleus / metabolism
  • Fabaceae / cytology
  • Fabaceae / drug effects
  • Fabaceae / genetics
  • Fabaceae / metabolism*
  • Molecular Sequence Data
  • Phosphorylation / drug effects
  • Plant Growth Regulators / pharmacology*
  • Plant Proteins / genetics
  • Protein Binding / drug effects
  • Protein Transport
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • RNA, Plant / genetics
  • RNA, Plant / metabolism
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Substrate Specificity
  • Two-Hybrid System Techniques


  • Plant Growth Regulators
  • Plant Proteins
  • RNA, Plant
  • RNA-Binding Proteins
  • dehydrin proteins, plant
  • Abscisic Acid
  • Protein-Serine-Threonine Kinases

Associated data

  • GENBANK/AF403292