Cytidine triphosphate synthase (CTPS)

Cytidine triphosphate synthase is a key enzyme (EC 6.3.4.2) in the de novo synthesis of pyrimidine nucleotides. It catalyzes the ATP- and glutamine-dependent amination of uridine triphosphate (UTP) to form cytidine triphosphate (CTP), which is essential for DNA, RNA, and phospholipid synthesis. CTPS is the rate-limiting step in cytosine nucleotide biosynthesis and is regulated by feedback from its product. The enzyme can polymerize into filaments ("cytoophidia") in cells, with regulatory implications. Increased CTPS activity has been observed in various cancers, and mutations confer drug resistance in some cell models. CTPS is a validated but challenging therapeutic target due to its central metabolic role and toxicity risks if inhibited in proliferating normal tissues.

Other names

CTP synthaseCTP synthetaseCTPSCTP enzymeEC 6.3.4.2

Competitive inhibition of CTP synthase activity; Depletion of cytidine triphosphate pool, inhibiting DNA/RNA synthesis; Disruption of nucleotide balance, blocking cell proliferation