title: Regulation of the wheat MAP kinase phosphatase 1 by 14-3-3 proteins.
abstract: Plant MAP kinase phosphatases (MKPs) are major regulators of MAPK signaling pathways and play crucial roles in controlling growth, development and stress responses. The presence of several functional domains in plant MKPs such as a dual specificity phosphatase catalytic domain, gelsolin, calmodulin-binding and serine-rich domains, suggests that MKPs can interact with distinct cellular partners, others than MAPKs. In this report, we identified a canonical mode I 14-3-3-binding motif (574KLPSLP579) located at the carboxy-terminal region of the wheat MKP, TMKP1. We found that this motif is well-conserved among other MKPs from monocots including Hordeum vulgare, Brachypodium distachyon and Aegilops taushii. Using co-immunoprecipitation assays, we provide evidence for interaction between TMKP1 and 14-3-3 proteins in wheat. Moreover, the phosphatase activity of TMKP1 is increased in a phospho-dependent manner by either Arabidopsis or yeast 14-3-3 isoforms. TMKP1 activation by 14-3-3 proteins is enhanced by Mn2+, whereas in the presence of Ca2+ions, TMKP1 activation was limited to Arabidopsis 14-3-3φ (phi), an isoform harboring an EF-hand motif. Such findings strongly suggest that 14-3-3 proteins, in conjunction with specific divalent cations, may stimulate TMKP1 activity and point-out that 14-3-3 proteins bind and regulate the activity of a MKP in eukaryotes.
authors.affiliation: Laboratory of Biotechnology and Plant Improvement, Center of Biotechnology of Sfax, BP1177, 3018 Sfax, Tunisia; Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 24, chemin de Borde-Rouge, BP 42617, 31326 Castanet-Tolosan, France.
authors.forename: Mouna
authors.initials: M
authors.lastname: Ghorbel
authors.affiliation: Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 24, chemin de Borde-Rouge, BP 42617, 31326 Castanet-Tolosan, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Cotelle
authors.affiliation: Laboratory of Biotechnology and Plant Improvement, Center of Biotechnology of Sfax, BP1177, 3018 Sfax, Tunisia; University of Sfax, Institute of Biotechnology, BP "1175", 3038 Sfax, Tunisia.
authors.forename: Chantal
authors.initials: C
authors.lastname: Ebel
authors.affiliation: Laboratory of Biotechnology and Plant Improvement, Center of Biotechnology of Sfax, BP1177, 3018 Sfax, Tunisia.
authors.forename: Ikram
authors.initials: I
authors.lastname: Zaidi
authors.affiliation: Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 24, chemin de Borde-Rouge, BP 42617, 31326 Castanet-Tolosan, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Ormancey
authors.affiliation: Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 24, chemin de Borde-Rouge, BP 42617, 31326 Castanet-Tolosan, France. Electronic address: galaud@lrsv.ups-tlse.fr.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Galaud
authors.affiliation: Laboratory of Biotechnology and Plant Improvement, Center of Biotechnology of Sfax, BP1177, 3018 Sfax, Tunisia; University of Sfax, Institute of Biotechnology, BP "1175", 3038 Sfax, Tunisia. Electronic address: moez.hanin@cbs.rnrt.tn.
authors.forename: Moez
authors.initials: M
authors.lastname: Hanin
mesh_terms: D048948:14-3-3 Proteins / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000918:Antibody Specificity / Q000276:immunology; D017360:Arabidopsis / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D017124:Conserved Sequence; D054638:Dual Specificity Phosphatase 1 / Q000737:chemistry / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation / Q000187:drug effects; D010940:Plant Proteins / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D012694:Serine / Q000235:genetics; D014908:Triticum / Q000187:drug effects / Q000201:enzymology*
chemical_list: D048948:14-3-3 Proteins; D002413:Cations, Divalent; D010940:Plant Proteins; D012694:Serine; D054638:Dual Specificity Phosphatase 1; D002118:Calcium
keywords: 14-3-3 Protein; Mitogen-activated protein kinase (MAPK); Phosphatase; Phosphorylation; TMKP1; Wheat