14-3-3 protein-activated and autoinhibited forms of plasma membrane H(+)-ATPase.
Several authors previously showed that the interaction between 14-3-3 proteins and plasma membrane H(+)-ATPase leads to an activated complex in which the enzyme is endowed with more favorable kinetic parameters and a more physiological pH optimum. In this paper we report immunological studies with antibodies covering a different specific region of the protein, including the N- and the C-terminal ends. The results showed that, beside a free and a complexed form, a third form of H(+)-ATPase in the cell must exist with low activity and no more activation due to the loss of a part of the C-terminal regulatory domain. A model in which 14-3-3 proteins activate H(+)-ATPase by protecting it from a specific proteolytic attack is presented and its generalization is discussed.
Malerba
M
M
Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Piazza della Scienza 2, Milan, 20126, Italy.
Bianchetti
R
R
D048948:14-3-3 Proteins; D000595:Amino Acid Sequence; D001152:Arsenicals / Q000378:metabolism; D015153:Blotting, Western; D002462:Cell Membrane / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D004791:Enzyme Inhibitors; D005033:Ethylmaleimide / Q000494:pharmacology; D006027:Glycosides / Q000494:pharmacology; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D015151:Immunoblotting; D008954:Models, Biological; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010769:Phosphothreonine / Q000378:metabolism; D019000:Phosphotyrosine / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*
D048948:14-3-3 Proteins; D001152:Arsenicals; D004791:Enzyme Inhibitors; D006027:Glycosides; D010940:Plant Proteins; C029341:oxophenylarsine; D010769:Phosphothreonine; C007808:fusicoccin; D019000:Phosphotyrosine; D014446:Tyrosine 3-Monooxygenase; D006180:Proton-Translocating ATPases; D005033:Ethylmaleimide