L-fucose kinase (FCSK)

L-fucose kinase (FCSK) is an enzyme that catalyzes the phosphorylation of L-fucose to form beta-L-fucose 1-phosphate, using ATP as the phosphate donor. This reaction is the first step in the salvage pathway for the reutilization of free L-fucose, which originates from glycoprotein and glycolipid degradation. The product of L-fucose kinase, fucose-1-phosphate, is subsequently used to generate GDP-fucose, the activated donor substrate required for all fucosyltransferases that attach fucose residues to protein or lipid glycans—a process vital to glycosylation. L-fucose and its derivatives play significant roles in mediating cell-cell interactions, including processes like blood group antigen formation, inflammation, and cancer metastasis. The enzyme belongs to the GHMP sugar kinase family, with a functional kinase domain located at the C-terminal region. The human L-fucose kinase protein consists of approximately 990 amino acids and has a predicted molecular mass of about 107 kDa. Genetic designation for human L-fucose kinase is "FCSK"; historical aliases include FUK. No known small-molecule drugs currently target L-fucose kinase, nor is there evidence it is used as a clinical biomarker or is associated with notable safety concerns. However, its function is essential for proper glycoprotein and glycolipid biosynthesis. Defects in fucokinase activity could contribute to abnormal glycosylation and associated pathology, but direct disease associations are limited in the literature.

Other names

fucokinasefucose kinaseL-fucokinaseATP:beta-L-fucose 1-phosphotransferaseATP:L-fucose 1-phosphotransferaseATP:6-deoxy-L-fucose 1-phosphotransferaseFUKFCSK

Phosphorylation of L-fucose to beta-L-fucose 1-phosphate, enabling its metabolic reutilization and further conversion to GDP-fucose