GRIM REAPER peptide binds to receptor kinase PRK5 to trigger cell death in Arabidopsis

EMBO J. 2015 Jan 2;34(1):55-66. doi: 10.15252/embj.201488582. Epub 2014 Nov 14.


Recognition of extracellular peptides by plasma membrane-localized receptor proteins is commonly used in signal transduction. In plants, very little is known about how extracellular peptides are processed and activated in order to allow recognition by receptors. Here, we show that induction of cell death in planta by a secreted plant protein GRIM REAPER (GRI) is dependent on the activity of the type II metacaspase METACASPASE-9. GRI is cleaved by METACASPASE-9 in vitro resulting in the release of an 11 amino acid peptide. This peptide bound in vivo to the extracellular domain of the plasma membrane-localized, atypical leucine-rich repeat receptor-like kinase POLLEN-SPECIFIC RECEPTOR-LIKE KINASE 5 (PRK5) and was sufficient to induce oxidative stress/ROS-dependent cell death. This shows a signaling pathway in plants from processing and activation of an extracellular protein to recognition by its receptor.

Keywords: ligand; protease; receptor‐like kinase; secreted protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Caspases / genetics
  • Caspases / metabolism*
  • Cell Death / physiology
  • Cell Membrane / genetics
  • Cell Membrane / metabolism
  • Oxidative Stress / physiology*
  • Peptides / genetics
  • Peptides / metabolism*
  • Protein Binding / physiology
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Protein Structure, Tertiary
  • Signal Transduction / physiology*


  • Arabidopsis Proteins
  • Peptides
  • Protein Kinases
  • Caspases
  • metacaspase 9, Arabidopsis