Cytosolic UDP-glucose pyrophosphorylase 2 (UGP2) catalyzes the reaction of UTP and glucose 1-phosphate to form UDP glucose and pyrophosphate (Knop and Hansen 1970; Duggleby et al. 1996). UGP2 is inferred to occur in the cell as a homooctamer from studies of its bovine homologue (Levine et al. 1969).