Fucokinase (FUK)

Abstract

Fucose from extracellular sources or the degradation of glycoconjugates is converted after cellular uptake by a salvage pathway leading to the formation of GDP-fucose. The first step requires the synthesis of β-l-fucose-1-phosphate by an ATP-dependent kinase reaction, which is catalyzed by l-fucose kinase (fucokinase) (Fig. 143.1). GDP-fucose is then formed by action of GDP-fucose pyrophosphorylase. Depending on tissue and physiological state, the salvage pathway usually contributes about 10 % to the total GDP-fucose pool, which is mainly fed by de novo synthesis from GDP-mannose (Fig. 143.1). Afterwards GDP-fucose is transported to the Golgi apparatus, where the fucose moiety is transferred to growing glycoconjugates by specific fucosyltransferases.