title: Phosphomimetic mutation of a conserved serine residue in Arabidopsis thaliana 14-3-3ω suggests a regulatory role of phosphorylation in dimerization and target interactions.
abstract: 14-3-3s are evolutionarily conserved eukaryotic regulatory proteins that are involved in diverse biological processes. The common mode of action for the 14-3-3 proteins is through the binding of phosphorylated target proteins. In many species, multiple 14-3-3 isoforms exist and these different isoforms can exhibit distinct ranges of target interactions. The dimerization of 14-3-3s is central to their function. 14-3-3 isoforms can form different combinations of homo- and heterodimers, which contribute to the broad functional diversity of the family. In this study, we showed that phosphomimetic mutation of a conserved serine residue in the dimerization interface of 14-3-3 isoforms, Ser-62, not only affects the ability of Arabidopsis 14-3-3ω to form homodimers, but alters the range of 14-3-3 family members with which it can form heterodimers. Furthermore, we demonstrated that the phosphorylation status of Ser-62 can regulate the binding of 14-3-3ω to target proteins, suggesting that Ser-62 might be a conserved key element to modulate target binding in both plants and animals.
authors.affiliation: Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Tufan
authors.initials: T
authors.lastname: Gökirmak
authors.affiliation: Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Fiona C
authors.initials: FC
authors.lastname: Denison
authors.affiliation: Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Beth J
authors.initials: BJ
authors.lastname: Laughner
authors.affiliation: Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611, USA; Genetics Institute, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Anna-Lisa
authors.initials: AL
authors.lastname: Paul
authors.affiliation: Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611, USA; Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611, USA; Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL 32611, USA. Electronic address: robferl@ufl.edu.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ferl
mesh_terms: D048948:14-3-3 Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence / Q000235:genetics*; D007700:Kinetics; D009154:Mutation / Q000235:genetics*; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055503:Protein Multimerization; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D012694:Serine / Q000235:genetics*
chemical_list: D048948:14-3-3 Proteins; C513203:14-3-3omega protein, Arabidopsis; D029681:Arabidopsis Proteins; D010750:Phosphoproteins; D020033:Protein Isoforms; D012694:Serine
keywords: 14-3-3 proteins; 14-3-3/target interactions; Arabidopsis thaliana; Binding kinetics; Dimerization; Phosphorylation