Ligand-dependent reduction in the membrane mobility of FLAGELLIN SENSITIVE2, an arabidopsis receptor-like kinase

Plant Cell Physiol. 2007 Nov;48(11):1601-11. doi: 10.1093/pcp/pcm132. Epub 2007 Oct 9.


Arabidopsis Flagellin sensitive2 (FLS2) is a transmembrane leucine-rich repeat receptor-like kinase, which recognizes a conserved 22 amino acid peptide (flg22) of bacterial flagellin and activates downstream defense signaling pathways resulting in enhanced resistance against plant pathogens. The underlying mechanisms for the activation of FLS2 in the cell membrane, however, are not fully understood. Using fluorescence recovery after photobleaching (FRAP), we demonstrate that approximately 75% of the FLS2 in the plasma membrane diffuses laterally with a diffusion coefficient of 0.34 microm(2) s(-1), indicating that it moves rapidly. Further, we show that FLS2 is less mobile in the presence of flg22, suggesting its ligand-dependent confinement to microdomains or transient interaction with other less mobile membrane proteins. Using an in vivo bimolecular fluorescence complementation (BiFC) system and fluorescence resonance energy transfer (FRET), which reveals in vivo protein-protein interactions, we show that FLS2 does not homodimerize either constitutively or in the presence of flg22. Our data suggest that the reduced mobility of FLS2 after binding flg22 and its existence in monomeric form are important mechanistic features of FLS2 early signaling.

Publication types

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

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Blotting, Western
  • Dimerization
  • Fluorescence Recovery After Photobleaching
  • Fluorescence Resonance Energy Transfer
  • Gene Expression Regulation, Plant
  • Ligands
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Protein Binding
  • Protein Kinases / chemistry
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism


  • Arabidopsis Proteins
  • Ligands
  • Membrane Proteins
  • Recombinant Proteins
  • Protein Kinases
  • FLS2 protein, Arabidopsis