Properties and physiological functions of UDP-sugar pyrophosphorylase in Arabidopsis.
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.
Kotake
Toshihisa
T
Division of Life Science, Graduate School of Science and Engineering, Saitama University, Shimo-Okubo, Saitama, Japan.
Hojo
Sachiko
S
Yamaguchi
Daisuke
D
Aohara
Tsutomu
T
Konishi
Tomoyuki
T
Tsumuraya
Yoichi
Y
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*
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; C036483:T-DNA; D014539:Uridine Diphosphate Sugars; D009713:Nucleotidyltransferases; C514559:UDP-sugar pyrophosphorylase, Arabidopsis