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).
14-3-3 proteins play a regulatory role in a diverse array of cellular functions such as apoptosis, regulation of the cell cycle, and regulation of gene transcription. The phytotoxin fusicoccin specifically induces association of virtually any 14-3-3 protein to plant plasma membrane H(+)-ATPase. The 14-3-3 binding site in the Arabidopsis plasma membrane H(+)-ATPase AHA2 was localized to the three C-terminal residues of the enzyme (Tyr(946)-Thr-Val). Binding of 14-3-3 protein to this target was induced by phosphorylation of Thr(947) (K(D) = 88 nM) and was in practice irreversible in the presence of fusicoccin (K(D) = 7 nM). Mass spectrometry analysis demonstrated that AHA2 expressed in yeast was phosphorylated at Thr(947). We conclude that the extreme end of AHA2 contains an unusual high-affinity binding site for 14-3-3 protein.
Fuglsang
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AT
Department of Plant Biology, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg, Copenhagen, Denmark.
Visconti
S
S
Drumm
K
K
Jahn
T
T
Stensballe
A
A
Mattei
B
B
Jensen
O N
ON
Aducci
P
P
Palmgren
M G
MG
D048948:14-3-3 Proteins; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011506:Proteins / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D015398:Signal Transduction; D013912:Threonine; D014443:Tyrosine; D014446:Tyrosine 3-Monooxygenase; D014633:Valine
D048948:14-3-3 Proteins; D011506:Proteins; D013912:Threonine; D014443:Tyrosine; D014446:Tyrosine 3-Monooxygenase; D006180:Proton-Translocating ATPases; D014633:Valine