Binding of phosphatidic acid to 14-3-3 proteins hampers their ability to activate the plant plasma membrane H+-ATPase.
Phosphatidic acid is a phospholipid second messenger implicated in various cellular processes in eukaryotes. In plants, production of phosphatidic acid is triggered in response to a number of biotic and abiotic stresses. Here, we show that phosphatidic acid binds to 14-3-3 proteins, a family of regulatory proteins which bind client proteins in a phosphorylation-dependent manner. Binding of phosphatidic acid involves the same 14-3-3 region engaged in protein target binding. Consequently, micromolar phosphatidic acid concentrations significantly hamper the interaction of 14-3-3 proteins with the plasma membrane H(+)-ATPase, a well characterized plant 14-3-3 target, thus inhibiting the phosphohydrolitic enzyme activity. Moreover, the proton pump is inhibited when endogenous PA production is triggered by phospholipase D and the G protein agonist mastoparan-7. Hence, our data propose a possible mechanism involving PA that regulates 14-3-3-mediated cellular processes in response to stress.
Department of Biology, University of Rome Tor Vergata, Rome, Italy. camoni@uniroma2.it
Lorenzo
L
Camoni
Cristina
C
Di Lucente
Roberta
R
Pallucca
Sabina
S
Visconti
Patrizia
P
Aducci
D048948:14-3-3 Proteins / Q000378:metabolism*; D020134:Catalytic Domain; D002462:Cell Membrane / Q000201:enzymology*; D004789:Enzyme Activation; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides / Q000494:pharmacology; D010712:Phosphatidic Acids / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism; D010766:Phosphorylation; D010940:Plant Proteins / Q000378:metabolism*; D011485:Protein Binding; D006180:Proton-Translocating ATPases / Q000096:biosynthesis*; D013312:Stress, Physiological; D003313:Zea mays / Q000201:enzymology / Q000502:physiology
D048948:14-3-3 Proteins; D036341:Intercellular Signaling Peptides and Proteins; C084070:Mas7 protein, synthetic; D010455:Peptides; D010712:Phosphatidic Acids; D010940:Plant Proteins; D010739:Phospholipase D; D006180:Proton-Translocating ATPases