title: Determining novel functions of Arabidopsis 14-3-3 proteins in central metabolic processes.
abstract: BACKGROUND
  14-3-3 proteins are considered master regulators of many signal transduction cascades in eukaryotes. In plants, 14-3-3 proteins have major roles as regulators of nitrogen and carbon metabolism, conclusions based on the studies of a few specific 14-3-3 targets.
  
  
  RESULTS
  In this study, extensive novel roles of 14-3-3 proteins in plant metabolism were determined through combining the parallel analyses of metabolites and enzyme activities in 14-3-3 overexpression and knockout plants with studies of protein-protein interactions. Decreases in the levels of sugars and nitrogen-containing-compounds and in the activities of known 14-3-3-interacting-enzymes were observed in 14-3-3 overexpression plants. Plants overexpressing 14-3-3 proteins also contained decreased levels of malate and citrate, which are intermediate compounds of the tricarboxylic acid (TCA) cycle. These modifications were related to the reduced activities of isocitrate dehydrogenase and malate dehydrogenase, which are key enzymes of TCA cycle. In addition, we demonstrated that 14-3-3 proteins interacted with one isocitrate dehydrogenase and two malate dehydrogenases. There were also changes in the levels of aromatic compounds and the activities of shikimate dehydrogenase, which participates in the biosynthesis of aromatic compounds.
  
  
  CONCLUSIONS
  Taken together, our findings indicate that 14-3-3 proteins play roles as crucial tuners of multiple primary metabolic processes including TCA cycle and the shikimate pathway.
authors: RIKEN Plant Science Center, Yokohama, Kanagawa 230-0045, Japan.
authors: Celine
authors: C
authors: Diaz
authors: Miyako
authors: M
authors: Kusano
authors: Ronan
authors: R
authors: Sulpice
authors: Mitsutaka
authors: M
authors: Araki
authors: Henning
authors: H
authors: Redestig
authors: Kazuki
authors: K
authors: Saito
authors: Mark
authors: M
authors: Stitt
authors: Ryoung
authors: R
authors: Shin
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002952:Citric Acid Cycle; D053858:Metabolic Networks and Pathways; D060066:Protein Interaction Maps; D012765:Shikimic Acid / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D048948:14-3-3 Proteins; D029681:Arabidopsis Proteins; D012765:Shikimic Acid