title: The mur4 mutant of arabidopsis is partially defective in the de novo synthesis of uridine diphospho L-arabinose.
abstract: To obtain information on the synthesis and function of arabinosylated glycans, the mur4 mutant of Arabidopsis was characterized. This mutation leads to a 50% reduction in the monosaccharide L-arabinose in most organs and affects arabinose-containing pectic cell wall polysaccharides and arabinogalactan proteins. Feeding L-arabinose to mur4 plants restores the cell wall composition to wild-type levels, suggesting a partial defect in the de novo synthesis of UDP-L-arabinose, the activated sugar used by arabinosyltransferases. The defect was traced to the conversion of UDP-D-xylose to UDP-L-arabinose in the microsome fraction of leaf material, indicating that mur4 plants are defective in a membrane-bound UDP-D-xylose 4-epimerase.
authors.affiliation: Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269, USA.
authors.forename: E G
authors.initials: EG
authors.lastname: Burget
authors.forename: W D
authors.initials: WD
authors.lastname: Reiter
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D001089:Arabinose / Q000378:metabolism; D002250:Carbon Radioisotopes; D002473:Cell Wall / Q000378:metabolism; D003433:Crosses, Genetic; D017343:Genes, Plant; D005947:Glucose / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis; D009154:Mutation; D018515:Plant Leaves / Q000378:metabolism; D011134:Polysaccharides / Q000096:biosynthesis; D011865:Radioisotope Dilution Technique; D014539:Uridine Diphosphate Sugars / Q000096:biosynthesis*
chemical_list: D002250:Carbon Radioisotopes; D006023:Glycoproteins; D011134:Polysaccharides; D014539:Uridine Diphosphate Sugars; C040817:uridine diphosphate arabinose; D001089:Arabinose; D005947:Glucose