PP2A-B'γ modulates foliar trans-methylation capacity and the formation of 4-methoxy-indol-3-yl-methyl glucosinolate in Arabidopsis leaves.
Glucosinolates (GSL) of cruciferous plants comprise a major group of structurally diverse secondary compounds which act as deterrents against aphids and microbial pathogens and have large commercial and ecological impacts. While the transcriptional regulation governing the biosynthesis and modification of GSL is now relatively well understood, post-translational regulatory components that specifically determine the structural variation of indole glucosinolates have not been reported. We show that the cytoplasmic protein phosphatase 2A regulatory subunit B'γ (PP2A-B'γ) physically interacts with indole glucosinolate methyltransferases and controls the methoxylation of indole glucosinolates and the formation of 4-methoxy-indol-3-yl-methyl glucosinolate in Arabidopsis leaves. By taking advantage of proteomic approaches and metabolic analysis we further demonstrate that PP2A-B'γ is required to control the abundance of oligomeric protein complexes functionally linked with the activated methyl cycle and the trans-methylation capacity of leaf cells. These findings highlight the key regulatory role of PP2A-B'γ in methionine metabolism and provide a previously unrecognized perspective for metabolic engineering of glucosinolate metabolism in cruciferous plants.
Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014, Turku, Finland.
Moona
M
Rahikainen
Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014, Turku, Finland.
Andrea
A
Trotta
Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014, Turku, Finland.
Sara
S
Alegre
Plant Physiology Lab, Organisms and Systems Biology, Faculty of Biology, University of Oviedo, Oviedo, Asturias, Spain.
Jesús
J
Pascual
Division of Plant Biology, Department of Biosciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
Katariina
K
Vuorinen
Division of Plant Biology, Department of Biosciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
Kirk
0000-0002-7398-3453
K
Overmyer
Department of Biology, University of Waterloo, 200 University Avenue, Ontario, N2L 3G1, Canada.
Barbara
B
Moffatt
Laboratoire de Physiologie Cellulaire et Végétale, CNRS UMR5168, INRA UMR1417, CEA, Université Grenoble Alpes, 38054, Grenoble, France.
Stéphane
S
Ravanel
Department of Plant Sciences, Technische Universität München, Emil-Ramann-Str.4, 85354, Freising, Germany.
Erich
E
Glawischnig
Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014, Turku, Finland.
Saijaliisa
0000-0002-7605-8546
S
Kangasjärvi
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D005961:Glucosinolates / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism; D008745:Methylation; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D005961:Glucosinolates; D021122:Protein Subunits; D008715:Methionine; D008780:Methyltransferases; C580624:PP2A-2 protein, Arabidopsis; D054648:Protein Phosphatase 2

Arabidopsis thaliana
; activated methyl cycle; glucosinolate; protein phosphatase 2A