UDP Glucose Pyrophosphorylase 2 is an important intermediary in mammalian carbohydrate interconversions. It transfers a glucose moiety from glucose-1-phosphate to MgUTP and forms UDP-glucose and MgPPi. In liver and muscle tissue, UDP-glucose is a direct precursor of glycogen; in lactating mammary gland it is converted to UDP-galactose which is then converted to lactose. The eukaryotic enzyme has no significant sequence similarity to the prokaryotic enzyme.

The UDPG gene encodes a predicted 508-amino acid protein with no homology to the bacterial protein, but with 47% identity with potato UDPG. On Northern blots, the 2.2-kb UDPG mRNA is expressed in all tissues tested, with the highest levels in skeletal muscle.