Handbook of Glycosyltransferases and Related Genes pp 1489-1495 | Cite as
N-Acetylglucosamine Kinase (NAGK)
N-Acetylglucosamine kinase (GlcNAc kinase; NAGK) catalyzes the phosphorylation of GlcNAc at C-6 by the use of ATP (Fig. 131.1). Cellular GlcNAc is usually provided by a de novo pathway starting from glycolysis at fructose 6-phosphate. Reutilization of GlcNAc from nutritional sources or lysosomal degradation of oligosaccharides is performed in a salvage pathway, which is initiated by GlcNAc kinase and the formation of GlcNAc 6-phosphate (Fig. 131.1). GlcNAc 6-phosphate then enters an anabolic pathway leading to the formation of UDP-GlcNAc, which is the substrate for the large set of GlcNAc transferases in complex oligosaccharide synthesis and the intracellular O-GlcNAc formation, or it is further metabolized to N-acetylneuraminic acid within the sialic acid biosynthesis (Fig. 131.1). GlcNAc 6-phosphate may also enter a catabolic pathway, which links hexosamine metabolism with the glycolytic pathway and the formation of fructose 6-phosphate.
KeywordsSialic Acid Salvage Pathway Saturation Transfer Difference Sugar Kinase GlcNAc Transferase
- Daviagnino J, Ureta T (1980) The identification of extrahepatic “glucokinase” as N-acetylglucosamine kinase. J Biol Chem 255:2633–2636Google Scholar
- Ligos JM, de Lera TL, Hinderlich S, Guinea B, Sánchez L, Roca R, Valencia A, Bernad A (2002) Functional interaction between the Ser/Thr kinase PKL12 and N-acetylglucosamine kinase, a prominent enzyme implicated in the salvage pathway for GlcNAc recycling. J Biol Chem 277:6333–6643PubMedCrossRefGoogle Scholar