Adenosine 5'-monophosphate inhibits the association of 14-3-3 proteins with the plant plasma membrane H(+)-ATPase.
Although a well ascertained evidence proves that the activity of the plant plasma membrane H(+)-ATPase is regulated by 14-3-3 proteins, information about physiological factors modulating the phosphorylation-dependent association between 14-3-3 proteins and the proton pump is largely incomplete. In this paper we show that the 5'-AMP-mimetic, 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), inhibits the fusicoccin-promoted proton extrusion in maize roots. We also demonstrate that 5'-AMP inhibits the association of 14-3-3 proteins with the C-terminal domain of the H(+)-ATPase in an overlay assay as well as the 14-3-3-dependent stimulation of the Arabidopsis thaliana H(+)-ATPase AHA1 isoform expressed in yeast membranes. Finally, by means of affinity chromatography with immobilized 5'-AMP and trinitrophenyl-AMP fluorescence analysis, we demonstrate that the 14-3-3 isoform GF14-6 from maize is able to bind 5'-AMP. The possible role of 5'-AMP as a general regulator of 14-3-3 functions in the plant cell is discussed.
Camoni
L
L
Department of Biology, University of Rome Tor Vergata, via della Ricerca Scientifica, I-00133, Rome, Italy.
Visconti
S
S
Marra
M
M
Aducci
P
P
D048948:14-3-3 Proteins; D000249:Adenosine Monophosphate / Q000494:pharmacology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D002462:Cell Membrane / Q000201:enzymology; D008969:Molecular Sequence Data; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D003313:Zea mays / Q000201:enzymology*
D048948:14-3-3 Proteins; D000249:Adenosine Monophosphate; D014446:Tyrosine 3-Monooxygenase; D006180:Proton-Translocating ATPases