Extracellular leucine-rich repeats as a platform for receptor/coreceptor complex formation

Proc Natl Acad Sci U S A. 2011 May 17;108(20):8503-7. doi: 10.1073/pnas.1103556108. Epub 2011 Apr 4.


Receptor kinases with leucine-rich repeat (LRR) extracellular domains form the largest family of receptors in plants. In the few cases for which there is mechanistic information, ligand binding in the extracellular domain often triggers the recruitment of a LRR-coreceptor kinase. The current model proposes that this recruitment is mediated by their respective kinase domains. Here, we show that the extracellular LRR domain of BRI1-ASSOCIATED KINASE1 (BAK1), a coreceptor involved in the disparate processes of cell surface steroid signaling and immunity in plants, is critical for its association with specific ligand-binding LRR-containing receptors. The LRRs of BAK1 thus serve as a platform for the molecular assembly of signal-competent receptors. We propose that this mechanism represents a paradigm for LRR receptor activation in plants.

Publication types

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

MeSH terms

  • Arabidopsis Proteins / metabolism*
  • Plants / enzymology*
  • Protein Kinases / metabolism*
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proteins / metabolism*
  • Repetitive Sequences, Amino Acid


  • Arabidopsis Proteins
  • Proteins
  • leucine-rich repeat proteins
  • Protein Kinases
  • BAK1 protein, Arabidopsis
  • BRI1 protein, Arabidopsis
  • Protein-Serine-Threonine Kinases