title: Identification and evolution of a plant cell wall specific glycoprotein glycosyl transferase, ExAD.
abstract: Extensins are plant cell wall glycoproteins that act as scaffolds for the deposition of the main wall carbohydrate polymers, which are interlocked into the supramolecular wall structure through intra- and inter-molecular iso-di-tyrosine crosslinks within the extensin backbone. In the conserved canonical extensin repeat, Ser-Hyp4, serine and the consecutive C4-hydroxyprolines (Hyps) are substituted with an α-galactose and 1-5 β- or α-linked arabinofuranoses (Arafs), respectively. These modifications are required for correct extended structure and function of the extensin network. Here, we identified a single Arabidopsis thaliana gene, At3g57630, in clade E of the inverting Glycosyltransferase family GT47 as a candidate for the transfer of Araf to Hyp-arabinofuranotriose (Hyp-β1,4Araf-β1,2Araf-β1,2Araf) side chains in an α-linkage, to yield Hyp-Araf4which is exclusively found in extensins. T-DNA knock-out mutants of At3g57630 showed a truncated root hair phenotype, as seen for mutants of all hitherto characterized extensin glycosylation enzymes; both root hair and glycan phenotypes were restored upon reintroduction of At3g57630. At3g57630 was named Extensin Arabinose Deficient transferase, ExAD, accordingly. The occurrence of ExAD orthologs within the Viridiplantae along with its' product, Hyp-Araf4, point to ExAD being an evolutionary hallmark of terrestrial plants and charophyte green algae.
authors.affiliation: Department of Plant and Environmental Sciences, VKR Research Centre, University of Copenhagen, Frederiksberg C, DK-1871, Denmark.
authors.forename: Svenning Rune
authors.initials: SR
authors.lastname: Møller
authors.affiliation: Department of Plant and Environmental Sciences, VKR Research Centre, University of Copenhagen, Frederiksberg C, DK-1871, Denmark.
authors.forename: Xueying
authors.initials: X
authors.lastname: Yi
authors.affiliation: Fundación Instituto Leloir and IIBBA-CONICET, Av. Patricia Argentinas 435, Buenos Aires, C1405BWE, Argentina.|Instituto de Fisiología, Biología Molecular y Neurociencias, IFIByNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón II, Buenos Aires, C1428EGA, Argentina.|Present address: Universität für Bodenkultur Wien (BOKU), Department for Applied Genetics and Cell Biology (DAGZ), Muthgasse 18, 1190 Vienna, Austria.
authors.forename: Silvia Melina
authors.initials: SM
authors.lastname: Velásquez
authors.affiliation: Institute for Plant Cell Biology and Biotechnology, Heinrich-Heine University, Duesseldorf, Germany.|Present address: Bayer Crop Science, Weed Control Research, Industriepark Höchst, 65926 Frankfurt am Main, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Gille
authors.affiliation: Department of Plant and Environmental Sciences, VKR Research Centre, University of Copenhagen, Frederiksberg C, DK-1871, Denmark.
authors.forename: Pernille Louise Munke
authors.initials: PLM
authors.lastname: Hansen
authors.affiliation: Department of Plant and Environmental Sciences, VKR Research Centre, University of Copenhagen, Frederiksberg C, DK-1871, Denmark.|Carlsberg Research Laboratory, J. C. Jacobsens Gade 4, Copenhagen V, 1799, Denmark.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Poulsen
authors.affiliation: Department of Plant and Environmental Sciences, VKR Research Centre, University of Copenhagen, Frederiksberg C, DK-1871, Denmark.
authors.forename: Carl Erik
authors.initials: CE
authors.lastname: Olsen
authors.affiliation: Department of Biological Chemistry, John Innes Centre, Norwich Research Park, NR4 7UH, Norwich, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Rejzek
authors.affiliation: Department of Plant and Environmental Sciences, VKR Research Centre, University of Copenhagen, Frederiksberg C, DK-1871, Denmark.|Present address: Department of Biochemistry, University of Cambridge, UK.
authors.forename: Harriet
authors.initials: H
authors.lastname: Parsons
authors.affiliation: Department of Molecular and Cellular Medicine and School of Dentistry, Copenhagen Center for Glycomics, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, DK-2200, Denmark.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Molecular and Cellular Medicine and School of Dentistry, Copenhagen Center for Glycomics, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, DK-2200, Denmark.
authors.forename: Hans H
authors.initials: HH
authors.lastname: Wandall
authors.affiliation: Department of Molecular and Cellular Medicine and School of Dentistry, Copenhagen Center for Glycomics, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, DK-2200, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Clausen
authors.affiliation: Department of Biological Chemistry, John Innes Centre, Norwich Research Park, NR4 7UH, Norwich, UK.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Field
authors.affiliation: Institute for Plant Cell Biology and Biotechnology, Heinrich-Heine University, Duesseldorf, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Pauly
authors.affiliation: Fundación Instituto Leloir and IIBBA-CONICET, Av. Patricia Argentinas 435, Buenos Aires, C1405BWE, Argentina.|Instituto de Fisiología, Biología Molecular y Neurociencias, IFIByNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón II, Buenos Aires, C1428EGA, Argentina.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Estevez
authors.affiliation: Carlsberg Research Laboratory, J. C. Jacobsens Gade 4, Copenhagen V, 1799, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Harholt
authors.affiliation: Department of Plant and Environmental Sciences, VKR Research Centre, University of Copenhagen, Frederiksberg C, DK-1871, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Ulvskov
authors.affiliation: Department of Plant and Environmental Sciences, VKR Research Centre, University of Copenhagen, Frederiksberg C, DK-1871, Denmark. blp@plen.ku.dk.
authors.forename: Bent Larsen
authors.initials: BL
authors.lastname: Petersen
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001089:Arabinose / Q000378:metabolism; D002473:Cell Wall / Q000201:enzymology / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000494:pharmacology; D019143:Evolution, Molecular; D055786:Gene Knockout Techniques; D006031:Glycosylation; D006602:Hexosyltransferases / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation; D018517:Plant Roots / Q000033:anatomy & histology*; D014995:Xylosidases / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; C036483:T-DNA; D001089:Arabinose; D006602:Hexosyltransferases; C020823:glycoprotein glycosyltransferase; C488780:ARAf protein, Arabidopsis; D014995:Xylosidases