title: The 14-3-3 isoforms chi and epsilon differentially bind client proteins from developing Arabidopsis seed.
abstract: The 14-3-3-protein family is prominently expressed during seed filling and modulates protein interactions and enzymatic activities, in a phosphorylation-dependent manner. To investigate the role(s) of 14-3-3 proteins in oilseed development, we have begun to characterize the Arabidopsis thaliana 14-3-3 "interactome" for two phylogenetically distinct isoforms. Proteins from developing Arabidopsis seed were incubated with a Sepharose affinity matrix containing covalently bound recombinant Arabidopsis 14-3-3 isoforms chi (χ) or epsilon (ε). Eluted proteins were quantitatively identified using GeLC-MS/MS coupled to spectral counting. Analysis of nine biological replicates revealed a total of 104 putative 14-3-3 binding proteins eluted from this affinity matrix compared to controls. Interestingly, these results imply that χ and ε could have distinct preferences for client proteins. Both isoforms interact with client proteins involved in various metabolic pathways, including glycolysis and de novo fatty acid synthesis. These results suggest 14-3-3 proteins interact with multiple biochemical processes of Arabidopsis seed development. Furthermore, these data suggest isoform specificity of client proteins and possibly even functional specialization between the 14-3-3 isoforms χ and ε in Arabidopsis seed development.
authors.affiliation: Interdisciplinary Plant Group and Department of Biochemistry, University of Missouri, Christopher S Bond Life Sciences Center, Columbia, Missouri 65211, United States.
authors.forename: Kirby N
authors.initials: KN
authors.lastname: Swatek
authors.forename: Katherine
authors.initials: K
authors.lastname: Graham
authors.forename: Ganesh K
authors.initials: GK
authors.lastname: Agrawal
authors.forename: Jay J
authors.initials: JJ
authors.lastname: Thelen
mesh_terms: D048948:14-3-3 Proteins / Q000737:chemistry / Q000378:metabolism*; D017360:Arabidopsis / Q000737:chemistry / Q000378:metabolism*; D002853:Chromatography, Liquid; D008954:Models, Biological; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods*; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D040901:Proteomics; D012639:Seeds / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
chemical_list: D048948:14-3-3 Proteins; D010940:Plant Proteins; D020033:Protein Isoforms