Blue light activates the plasma membrane H(+)-ATPase by phosphorylation of the C-terminus in stomatal guard cells

EMBO J. 1999 Oct 15;18(20):5548-58. doi: 10.1093/emboj/18.20.5548.


The opening of stomata, which is driven by the accumulation of K(+) salt in guard cells, is induced by blue light (BL). The BL activates the H(+) pump; however, the mechanism by which the perception of BL is transduced into the pump activation remains unknown. We present evidence that the pump is the plasma membrane H(+)-ATPase and that BL activates the H(+)-ATPase via phosphorylation. A pulse of BL (30 s, 100 micromol/m(2)/s) increased ATP hydrolysis by the plasma membrane H(+)-ATPase and H(+) pumping in Vicia guard cell protoplasts with a similar time course. The H(+)-ATPase was phosphorylated reversibly by BL, and the phosphorylation levels paralleled the ATP hydrolytic activity. The phosphorylation occurred exclusively in the C-termini of H(+)-ATPases on both serine and threonine residues in two isoproteins of H(+)-ATPase in guard cells. An endogenous 14-3-3 protein was co-precipitated with H(+)-ATPase, and the recombinant 14-3-3 protein bound to the phosphorylated C-termini of H(+)-ATPases. These findings demonstrate that BL activates the plasma membrane H(+)-ATPase via phosphorylation of the C-terminus by a serine/threonine protein kinase, and that the 14-3-3 protein has a key role in the activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins
  • Adenosine Triphosphate / metabolism
  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites
  • Cell Membrane / enzymology
  • DNA Primers / genetics
  • Enzyme Activation / radiation effects
  • Fabaceae / enzymology*
  • Fabaceae / genetics
  • Fabaceae / radiation effects
  • Hydrolysis
  • Light
  • Molecular Sequence Data
  • Phosphorylation
  • Plants, Medicinal*
  • Proteins / isolation & purification
  • Proteins / metabolism
  • Proton Pumps / metabolism
  • Proton Pumps / radiation effects
  • Proton-Translocating ATPases / genetics
  • Proton-Translocating ATPases / metabolism
  • Proton-Translocating ATPases / radiation effects*
  • Sequence Homology, Amino Acid
  • Tyrosine 3-Monooxygenase*


  • 14-3-3 Proteins
  • DNA Primers
  • Proteins
  • Proton Pumps
  • Adenosine Triphosphate
  • Tyrosine 3-Monooxygenase
  • Proton-Translocating ATPases