Site-specific regulatory interaction between spinach leaf sucrose-phosphate synthase and 14-3-3 proteins.
We report an Mg2+-dependent interaction between spinach leaf sucrose-phosphate synthase (SPS) and endogenous 14-3-3 proteins, as evidenced by co-elution during gel filtration and co-immunoprecipitation. The content of 14-3-3s associated with an SPS immunoprecipitate was inversely related to activity, and was specifically reduced when tissue was pretreated with 5-aminoimidazole-4-carboxamide riboside, suggesting metabolite control in vivo. A synthetic phosphopeptide based on Ser-229 was shown by surface plasmon resonance to bind a recombinant plant 14-3-3, and addition of the phosphorylated SPS-229 peptide was found to stimulate the SPS activity of an SPS:14-3-3 complex. Taken together, the results suggest a regulatory interaction of 14-3-3 proteins with Ser-229 of SPS.
US Department of Agriculture, Agricultural Research Service and Department of Crop Science, North Carolina State University, Raleigh 27695-7631, USA.
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Toroser
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Athwal
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Huber
D048948:14-3-3 Proteins; D000595:Amino Acid Sequence; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives / Q000494:pharmacology; D001665:Binding Sites; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology; D005964:Glucosyltransferases / Q000187:drug effects / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D010766:Phosphorylation; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology*; D011506:Proteins / Q000378:metabolism* / Q000494:pharmacology; D012265:Ribonucleotides / Q000494:pharmacology; D012694:Serine / Q000378:metabolism; D018724:Spinacia oleracea / Q000187:drug effects / Q000201:enzymology*; D014446:Tyrosine 3-Monooxygenase
D048948:14-3-3 Proteins; D004791:Enzyme Inhibitors; D010446:Peptide Fragments; D011506:Proteins; D012265:Ribonucleotides; D000620:Aminoimidazole Carboxamide; D012694:Serine; D014446:Tyrosine 3-Monooxygenase; D005964:Glucosyltransferases; C022698:sucrose-phosphate synthase; C031143:AICA ribonucleotide; D008274:Magnesium