Functional Identification of Two Nonredundant Arabidopsis α(1,2)Fucosyltransferases Specific to Arabinogalactan Proteins

• DOI: 10.1074/jbc.m110.102715
• Publication Date: 2010-03-02T03:55:22Z
• Authors: Yingying Wu; Matthew Williams; Sophie Bernard; Azeddine Driouich; Allan M. Showalter; Ahmed Faik
• Keywords: Arabinogalactan; Fucosyltransferase; Molecular mass; Fucosylation

Virtually nothing is known about the mechanisms and enzymes responsible for glycosylation of arabinogalactan proteins (AGPs). The glycosyltransferase 37 family contains plant-specific enzymes, which suggests involvement in organs such as cell wall. Our working hypothesis that AtFUT4 AtFUT6 genes encode alpha(1,2)fucosyltransferases (FUTs) AGPs. Multiple lines evidence support this hypothesis. First, overexpression two tobacco BY2 cells, to contain nonfucosylated AGPs, resulted a staining transgenic cells with eel lectin, specifically binds terminal alpha-linked fucose. Second, monosaccharide analysis by high pH anion exchange chromatography electrospray ionization mass spectrometry indicated presence fucose AGPs from but not wild type cells. Third, detergent extracts microsomal membranes prepared were able fucosylate, vitro, purified Susceptibility [(14)C]fucosylated alpha(1,2)fucosidase, alpha(1,3/4)fucosidase, an alpha(1,2) linkage formed. Furthermore, dearabinosylated substrate acceptors these indicating arabinosyl residues represent fucosylation sites on molecules. Testing several polysaccharides, oligosaccharides, glycoproteins potential fucosyl transfer reactions are specific functionally redundant because they differentially fucosylate certain first be characterized AGP further our understanding wall biosynthesis.