title: Properties and physiological functions of UDP-sugar pyrophosphorylase in Arabidopsis.
abstract: UDP-sugar pyrophosphorylase catalyzes the conversion of various monosaccharide 1-phosphates to the respective UDP-sugars in the salvage pathway. Using the genomic database, we cloned a putative gene for UDP-sugar pyrophosphorylase from Arabidopsis. Although relatively stronger expression was detected in the vascular tissue of leaves and the pollen, AtUSP is expressed in most cell types of Arabidopsis, indicating a housekeeping function in nucleotide sugar metabolism. Recombinant AtUSP expressed in Escherichia coli exhibited broad specificity toward monosaccharide 1-phosphates, resulting in the formation of various UDP-sugars such as UDP-glucose, -galactose, -glucuronic acid, -xylose and -L-arabinose. A loss-of-function mutation in the AtUSP gene caused by T-DNA insertion completely abolished male fertility. These results indicate that AtUSP functions as a UDP-sugar pyrophosphorylase in the salvage pathway, and that the generation of UDP-sugars from monosaccharide 1-phosphates catalyzed by AtUSP is essential for pollen development in Arabidopsis.
authors.affiliation: Division of Life Science, Graduate School of Science and Engineering, Saitama University, Shimo-Okubo, Saitama, Japan.
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Kotake
authors.forename: Sachiko
authors.initials: S
authors.lastname: Hojo
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamaguchi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Aohara
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Konishi
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Tsumuraya
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D004269:DNA, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009713:Nucleotidyltransferases / Q000235:genetics / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology; D011058:Pollen / Q000502:physiology; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014539:Uridine Diphosphate Sugars / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; C036483:T-DNA; D014539:Uridine Diphosphate Sugars; D009713:Nucleotidyltransferases; C514559:UDP-sugar pyrophosphorylase, Arabidopsis