The 14-3-3 protein interacts directly with the C-terminal region of the plant plasma membrane H(+)-ATPase.
Accumulating evidence suggests that 14-3-3 proteins are involved in the regulation of plant plasma membrane H(+)-ATPase activity. However, it is not known whether the 14-3-3 protein interacts directly or indirectly with the H(+)-ATPase. In this study, detergent-solubilized plasma membrane H(+)-ATPase isolated from fusicoccin-treated maize shoots was copurified with the 14-3-3 protein (as determined by protein gel blotting), and the H(+)-ATPase was recovered in an activated state. In the absence of fusicoccin treatment, H(+)-ATPase and the 14-3-3 protein were well separated, and the H(+)-ATPase was recovered in a nonactivated form. Trypsin treatment removed the 10-kD C-terminal region from the H(+)-ATPase as well as the 14-3-3 protein. Using the yeast two-hybrid system, we could show a direct interaction between Arabidopsis 14-3-3 GF14-phi and the last 98 C-terminal amino acids of the Arabidopsis AHA2 plasma membrane H(+)-ATPase. We propose that the 14-3-3 protein is a natural ligand of the plasma membrane H(+)-ATPase, regulating proton pumping by displacing the C-terminal autoinhibitory domain of the H(+)-ATPase.
Jahn
T
T
Department of Plant Biochemistry, Lund University, Sweden. tjahn@pfa.molbio.ku.dk
Fuglsang
A T
AT
Olsson
A
A
Brüntrup
I M
IM
Collinge
D B
DB
Volkmann
D
D
Sommarin
M
M
Palmgren
M G
MG
Larsson
C
C
D048948:14-3-3 Proteins; D000255:Adenosine Triphosphate / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology; D002850:Chromatography, Gel; D015180:Electrophoresis, Gel, Two-Dimensional; D006027:Glycosides / Q000494:pharmacology; D006868:Hydrolysis; D011485:Protein Binding; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000302:isolation & purification / Q000378:metabolism*; D014446:Tyrosine 3-Monooxygenase; D003313:Zea mays / Q000201:enzymology*
D048948:14-3-3 Proteins; D006027:Glycosides; D011506:Proteins; C007808:fusicoccin; D000255:Adenosine Triphosphate; D014446:Tyrosine 3-Monooxygenase; D006180:Proton-Translocating ATPases