Figure 10.

The hexosamine pathway generates glycoconjugates. Fructose 6-phosphate can be converted into glucosamine 6-phosphate by GFAT to initiate the hexosamine pathway, which, through a series of reactions, generates UDP-N-acetylglucosamine (UDP-GlcNAC) and N-acetylgalactosamine (UDP-GalNAC), which are used to generate glycolipids, proteoglycans, and glycoproteins. OGT uses UDP-GlcNAc to O-GlcNAcylate serine and threonine residues of proteins to modify their activity. These proteins can have their GlcNAc moiety removed by OGA.