Tyrosine phosphorylation inhibits the interaction of 14-3-3 proteins with the plant plasma membrane H+-ATPase.
Interaction of 14-3-3 proteins with their targets depends not only on the phosphorylation status of the target but also on that of 14-3-3 (Fu et al., 2000). In this work we demonstrated that the maize 14-3-3 isoform GF14-6 is a substrate of the tyrosine kinase insulin growth factor receptor 1. By means of site-directed mutants of GF14-6, we identified Tyr-137 as the specific tyrosine residue phosphorylated by the insulin growth factor receptor 1. Phosphorylation of GF14-6 on Tyr-137 lowered its affinity for a peptide mimicking the 14-3-3 binding site of the plant plasma membrane H+-ATPase. Moreover, phosphorylation in planta of 14-3-3 tyrosine residues, resulting from incubation with the tyrosine phosphatase inhibitor, phenylarsine oxide, decreased their association to the H+-ATPase.
Giacometti
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Dipartimento di Biologia "L. Gorini", Università di Milano, CNR Istituto di Biofisica - Sezione di Milano, via G. Celoria 26, 20133 Milano, Italy.
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D048948:14-3-3 Proteins; D017360:Arabidopsis / Q000378:metabolism; D001152:Arsenicals / Q000494:pharmacology; D001483:Base Sequence; D002462:Cell Membrane / Q000201:enzymology; D018744:DNA, Plant / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014443:Tyrosine / Q000737:chemistry*; D014446:Tyrosine 3-Monooxygenase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D003313:Zea mays / Q000235:genetics / Q000378:metabolism
D048948:14-3-3 Proteins; D001152:Arsenicals; D018744:DNA, Plant; D004791:Enzyme Inhibitors; D010940:Plant Proteins; D011994:Recombinant Proteins; C029341:oxophenylarsine; D014443:Tyrosine; D014446:Tyrosine 3-Monooxygenase; D017526:Receptor, IGF Type 1; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases; D006180:Proton-Translocating ATPases