Binding of 14-3-3 protein to the plasma membrane H+-ATPase AHA2 involves the three C-terminal residues Tyr(946)-Thr-Val and requires phosphorylation of Thr(947)
At. Fuglsang et al., Binding of 14-3-3 protein to the plasma membrane H+-ATPase AHA2 involves the three C-terminal residues Tyr(946)-Thr-Val and requires phosphorylation of Thr(947), J BIOL CHEM, 274(51), 1999, pp. 36774-36780
14-3-3 proteins play a regulatory role in a diverse array of cellular funct
ions such as apoptosis, regulation of the cell cycle, and regulation of gen
e transcription. The phytotoxin fusicoccin specifically induces association
of virtually any 14-3-3 protein to plant plasma membrane Hf-ATPase. The 14
-3-3 binding site in the Arabidopsis plasma membrane H+-ATPase AHA2 was loc
alized to the three C-terminal residues of the enzyme (Tyr(946)-Thr-Val). f
inding of 14-3-3 protein to this target was induced by phosphorylation of T
hr(947) (K-D = 88 nM) and was in practice irreversible in the presence of f
usicoccin (K-D = 7 nM). Mass spectrometry analysis demonstrated that AHA2 e
xpressed in yeast was phosphorylated at Thr(947). We conclude that the extr
eme end of AHA2 contains an unusual high-affinity binding site for 14-3-3 p
rotein.