title: Myrosinases TGG1 and TGG2 from Arabidopsis thaliana contain exclusively oligomannosidic N-glycans.
abstract: In all eukaryotes N-glycosylation is the most prevalent protein modification of secretory and membrane proteins. Although the N-glycosylation capacity and the individual steps of the N-glycan processing pathway have been well studied in the model plant Arabidopsis thaliana, little attention has been paid to the characterization of the glycosylation status of individual proteins. We report here the structural analysis of all N-glycans present on the endogenous thioglucoside glucohydrolases (myrosinases) TGG1 and TGG2 from A. thaliana. All nine glycosylation sites of TGG1 and all four glycosylation sites of TGG2 are occupied by oligomannosidic structures with Man₅GlcNAc₂ as the major glycoform. Analysis of the oligomannosidic isomers from wild-type plants and mannose trimming deficient mutants by liquid chromatography with porous graphitic carbon and mass spectrometry revealed that the N-glycans from both myrosinases are processed by Golgi-located α-mannosidases.
authors.affiliation: Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria.
authors.forename: Eva
authors.initials: E
authors.lastname: Liebminger
authors.forename: Josephine
authors.initials: J
authors.lastname: Grass
authors.forename: Jakub
authors.initials: J
authors.lastname: Jez
authors.forename: Laura
authors.initials: L
authors.lastname: Neumann
authors.forename: Friedrich
authors.initials: F
authors.lastname: Altmann
authors.forename: Richard
authors.initials: R
authors.lastname: Strasser
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002236:Carbohydrate Conformation; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006031:Glycosylation; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D011134:Polysaccharides; D006026:Glycoside Hydrolases; C511862:TGG1 protein, Arabidopsis; C511863:TGG2 protein, Arabidopsis