BRI1/BAK1, a receptor kinase pair mediating brassinosteroid signaling

Cell. 2002 Jul 26;110(2):203-12. doi: 10.1016/s0092-8674(02)00814-0.


The Arabidopsis BAK1 (BRI1 Associated receptor Kinase 1) was identified by a yeast two-hybrid screen as a specific interactor for BRI1, a critical component of a membrane brassinosteroid (BR) receptor. In yeast, BAK1/BRI1 interaction activates their kinase activities through transphosphorylation. BAK1 and BRI1 share similar gene expression and subcellular localization patterns and physically associate with each other in plants. Overexpression of the BAK1 gene leads to a phenotype reminiscent of BRI1-overexpression transgenic plants and rescues a weak bri1 mutant. In contrast, a bak1 knockout mutation gives rise to a weak bri1-like phenotype and enhances a weak bri1 mutation. We propose that BAK1 and BRI1 function together to mediate plant steroid signaling.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis
  • Arabidopsis Proteins
  • DNA, Bacterial
  • Enzyme Activation
  • Gene Expression
  • Genes, Plant
  • Hydroxysteroids / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Molecular Sequence Data
  • Mutagenesis, Insertional
  • Phenotype
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Saccharomyces cerevisiae
  • Signal Transduction / physiology*
  • Two-Hybrid System Techniques


  • Arabidopsis Proteins
  • DNA, Bacterial
  • Hydroxysteroids
  • Membrane Proteins
  • T-DNA
  • Protein Kinases
  • BAK1 protein, Arabidopsis
  • BRI1 protein, Arabidopsis
  • Protein-Serine-Threonine Kinases