A WNK kinase binds and phosphorylates V-ATPase subunit C

FEBS Lett. 2006 Feb 6;580(3):932-9. doi: 10.1016/j.febslet.2006.01.018. Epub 2006 Jan 18.


WNK (with no lysine (K)) protein kinases are found in many eukaryotes and share a unique active site. Here, we report that a member of the Arabidopsis WNK family (AtWNK8) interacts with subunit C of the vacuolar H+-ATPase (V-ATPase) via a short C-terminal domain. AtWNK8 is shown to autophosphorylate intermolecularly and to phosphorylate Arabidopsis subunit C (AtVHA-C) at multiple sites as determined by MALDI-TOF MS analysis. Furthermore, we show that AtVHA-C and other V-ATPase subunits are phosphorylated when V1-complexes are used as substrates for AtWNK8. Taken together, our results provide evidence that V-ATPases are potential targets of WNK kinases and their associated signaling pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Binding Sites / physiology
  • Phosphorylation
  • Protein Binding / physiology
  • Protein Processing, Post-Translational / physiology*
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Signal Transduction / physiology*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods
  • Two-Hybrid System Techniques
  • Vacuolar Proton-Translocating ATPases / genetics
  • Vacuolar Proton-Translocating ATPases / metabolism*


  • Arabidopsis Proteins
  • Protein-Serine-Threonine Kinases
  • WNK8 protein, Arabidopsis
  • Det3 protein, Arabidopsis
  • Vacuolar Proton-Translocating ATPases