title: Identification of an N-acetylglucosamine kinase essential for UDP-N-acetylglucosamine salvage synthesis in Arabidopsis.
abstract: Uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) donates GlcNAc for various glycans and glycoconjugates. We previously found that GlcNAc supplementation increases the UDP-GlcNAc content in Arabidopsis; however, the metabolic pathway was undefined. Here, we show that the homolog of human GlcNAc kinase (GNK) is conserved in land plants. Enzymatic assays of the Arabidopsis homologous protein (AtGNK) revealed kinase activity that was highly specific for GlcNAc. We also demonstrate the role of AtGNK in plants by using its knockout mutant, which presents lower UDP-GlcNAc contents and is insensitive to GlcNAc supplementation. Moreover, our results demonstrate the presence of a GlcNAc salvage pathway in plants.
authors.affiliation: Department of Biology, Faculty of Science, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Furo
authors.affiliation: Biology and Environmental Science, Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Nozaki
authors.affiliation: Department of Biology, Faculty of Science, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Murashige
authors.affiliation: Biology and Environmental Science, Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan. Electronic address: ysato@sci.ehime-u.ac.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sato
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D055786:Gene Knockout Techniques; D006801:Humans; D009154:Mutation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013379:Substrate Specificity; D014536:Uridine Diphosphate N-Acetylgalactosamine / Q000096:biosynthesis*
chemical_list: D029681:Arabidopsis Proteins; D014536:Uridine Diphosphate N-Acetylgalactosamine; D017853:Phosphotransferases (Alcohol Group Acceptor); C018716:N-acetylglucosamine kinase; D000117:Acetylglucosamine
keywords: GlcNAc salvage pathway; Hexosamine pathway; N-Acetylglucosamine kinase; UDP-GlcNAc