DCK, Deoxycytidine kinase

Deoxycytidine kinase is responsible for the phosphorylation of several deoxyribonucleosides and their analogs. Deficiency of this enzyme activity is associated with resistance to antiviral and anticancer chemotherapeutic agents, whereas increased enzyme activity is associated with increased activation of these compounds to cytotoxic nucleoside triphosphate derivatives. It is the rate limiting enzyme in the activation of many important anticancer and retroviral drugs and its activity is often decreased in cells that are resistant to cytosine arabinoside.