Cytidine and uridine are transported through their corresponding nucleoside hydrogen symporters. Once cytidine is incorporated into the cytosol, it is deaminated through a reaction with water and a hydrogen ion through a cytidine deaminase resulting in the release of ammonium and uridine. Uridine is then lyased by a phosphate through a uridine phosphorylase resulting in the release of a uracil and an alpha-D-ribose-1-phosphate. This compound is then transformed into an isomer D-ribose 5-phosphate through an alpha-D-ribose 1,5-phosphomutase. This compound is then incorporated into the pentose phosphate pathway.

Pyrimidine Ribonucleosides Degradation References