title: Posttranslational modifications of FERREDOXIN-NADP+ OXIDOREDUCTASE in Arabidopsis chloroplasts.
abstract: Rapid responses of chloroplast metabolism and adjustments to photosynthetic machinery are of utmost importance for plants' survival in a fluctuating environment. These changes may be achieved through posttranslational modifications of proteins, which are known to affect the activity, interactions, and localization of proteins. Recent studies have accumulated evidence about the crucial role of a multitude of modifications, including acetylation, methylation, and glycosylation, in the regulation of chloroplast proteins. Both of the Arabidopsis (Arabidopsis thaliana) leaf-type FERREDOXIN-NADP(+) OXIDOREDUCTASE (FNR) isoforms, the key enzymes linking the light reactions of photosynthesis to carbon assimilation, exist as two distinct forms with different isoelectric points. We show that both AtFNR isoforms contain multiple alternative amino termini and undergo light-responsive addition of an acetyl group to the α-amino group of the amino-terminal amino acid of proteins, which causes the change in isoelectric point. Both isoforms were also found to contain acetylation of a conserved lysine residue near the active site, while no evidence for in vivo phosphorylation or glycosylation was detected. The dynamic, multilayer regulation of AtFNR exemplifies the complex regulatory network systems controlling chloroplast proteins by a range of posttranslational modifications, which continues to emerge as a novel area within photosynthesis research.
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Nina
authors.initials: N
authors.lastname: Lehtimäki
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Minna M
authors.initials: MM
authors.lastname: Koskela
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Käthe M
authors.initials: KM
authors.lastname: Dahlström
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Eveliina
authors.initials: E
authors.lastname: Pakula
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Minna
authors.initials: M
authors.lastname: Lintala
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Martin
authors.initials: M
authors.lastname: Scholz
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Michael
authors.initials: M
authors.lastname: Hippler
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Guy T
authors.initials: GT
authors.lastname: Hanke
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Anne
authors.initials: A
authors.lastname: Rokka
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Natalia
authors.initials: N
authors.lastname: Battchikova
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.).
authors.forename: Tiina A
authors.initials: TA
authors.lastname: Salminen
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20520 Turku, Finland (N.L., M.M.K., E.P., M.L., N.B., P.M.);Structural Bioinformatics Laboratory, Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland (K.M.D., T.A.S.);Institute of Plant Biology and Biotechnology, Faculty of Biology, Westfälische Wilhelms-Universität Münster, DE-48143 Muenster, Germany (M.S., M.H.);Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, DE-49076 Osnabruck, Germany (G.T.H.); andTurku Centre for Biotechnology, FI-20520 Turku, Finland (A.R.) pmulo@utu.fi.
authors.forename: Paula
authors.initials: P
authors.lastname: Mulo
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology; D005287:Ferredoxin-NADP Reductase / Q000235:genetics / Q000378:metabolism*; D005288:Ferredoxins / Q000378:metabolism; D006031:Glycosylation; D007527:Isoenzymes; D008027:Light; D008961:Models, Structural; D008969:Molecular Sequence Data; D009249:NADP / Q000378:metabolism; D010766:Phosphorylation; D010788:Photosynthesis; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics; D011499:Protein Processing, Post-Translational; D016415:Sequence Alignment
chemical_list: D029681:Arabidopsis Proteins; D005288:Ferredoxins; D007527:Isoenzymes; D009249:NADP; D005287:Ferredoxin-NADP Reductase