title: Protein N-acylation overrides differing targeting signals.
abstract: In a bioinformatics based screen for chloroplast-localized protein kinases we noticed that available protein targeting predictors falsely predicted chloroplast localization. This seems to be due to interference with N-terminal protein acylation, which is of particular importance for protein kinases. Their N-myristoylation was found to be highly overrepresented in the proteome, whereas myristoylation motifs are almost absent in known chloroplast proteins. However, only abolishing their myristoylation was not sufficient to target those kinases to chloroplasts and resulted in nuclear accumulation instead. In contrast, inhibition of N-myristoylation of a calcium-dependent protein kinase was sufficient to alter its localization from the plasma membrane to chloroplasts and chloroplast localization of ferredoxin-NADP+ reductase and Rubisco activase could be efficiently suppressed by artificial introduction of myristoylation and palmitoylation sites.
authors.affiliation: Department of Biochemistry and Cell Biology, MFPL, University of Vienna. Dr. Bohrgasse 9, A-1030 Vienna, Austria.
authors.forename: Simon
authors.initials: S
authors.lastname: Stael
authors.affiliation: Department of Biochemistry and Cell Biology, MFPL, University of Vienna. Dr. Bohrgasse 9, A-1030 Vienna, Austria.
authors.forename: Roman G
authors.initials: RG
authors.lastname: Bayer
authors.affiliation: Department of Biochemistry and Cell Biology, MFPL, University of Vienna. Dr. Bohrgasse 9, A-1030 Vienna, Austria.
authors.forename: Norbert
authors.initials: N
authors.lastname: Mehlmer
authors.affiliation: Department of Biochemistry and Cell Biology, MFPL, University of Vienna. Dr. Bohrgasse 9, A-1030 Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Teige
mesh_terms: D000215:Acylation; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology* / Q000378:metabolism; D005287:Ferredoxin-NADP Reductase / Q000235:genetics / Q000378:metabolism; D054878:Lipoylation; D050505:Mutant Proteins / Q000378:metabolism; D019814:Myristic Acid / Q000378:metabolism; D019308:Palmitic Acid / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D017871:Calcium-Calmodulin-Dependent Protein Kinases
chemical_list: D029681:Arabidopsis Proteins; D005287:Ferredoxin-NADP Reductase; D050505:Mutant Proteins; D019814:Myristic Acid; D019308:Palmitic Acid; D010940:Plant Proteins; D011494:Protein Kinases; D011993:Recombinant Fusion Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C054765:rca protein, plant