title: Phosphorylation-dependent interaction between plant plasma membrane H(+)-ATPase and 14-3-3 proteins.
abstract: The H(+)-ATPase is a key enzyme for the establishment and maintenance of plasma membrane potential and energization of secondary active transport in the plant cell. The phytotoxin fusicoccin induces H(+)-ATPase activation by promoting the association of 14-3-3 proteins. It is still unclear whether 14-3-3 proteins can represent natural regulators of the proton pump, and factors regulating 14-3-3 binding to the H(+)-ATPase under physiological conditions are unknown as well. In the present study in vivo and in vitro evidence is provided that 14-3-3 proteins can associate with the H(+)-ATPase from maize roots also in a fusicoccin-independent manner and that the interaction depends on the phosphorylation status of the proton pump. Furthermore, results indicate that phosphorylation of H(+)-ATPase influences also the fusicoccin-dependent interaction of 14-3-3 proteins. Finally, a protein phosphatase 2A able to impair the interaction between H(+)-ATPase and 14-3-3 proteins was identified and partially purified from maize root.
authors.affiliation: Department of Biology, University of Rome "Tor Vergata," via della Ricerca Scientifica, I-00133, Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Camoni
authors.forename: V
authors.initials: V
authors.lastname: Iori
authors.forename: M
authors.initials: M
authors.lastname: Marra
authors.forename: P
authors.initials: P
authors.lastname: Aducci
mesh_terms: D048948:14-3-3 Proteins; D000469:Alkaline Phosphatase / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000378:metabolism*; D006027:Glycosides / Q000494:pharmacology; D007700:Kinetics; D019319:Okadaic Acid / Q000494:pharmacology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D018517:Plant Roots / Q000378:metabolism; D011485:Protein Binding; D054648:Protein Phosphatase 2; D011506:Proteins / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase; D003313:Zea mays / Q000378:metabolism*
chemical_list: D048948:14-3-3 Proteins; D004791:Enzyme Inhibitors; D006027:Glycosides; D011506:Proteins; D019319:Okadaic Acid; C007808:fusicoccin; D014446:Tyrosine 3-Monooxygenase; D000469:Alkaline Phosphatase; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; D006180:Proton-Translocating ATPases