DNA synthesis pathway via pyrimidine analog incorporation

The DNA synthesis pathway via pyrimidine analog incorporation refers to the set of enzymatic and metabolic processes that allow chemically modified pyrimidine nucleoside analogs to be taken up by cells and incorporated into DNA during replication, either by endogenous DNA polymerases or specialized translesion-synthesis polymerases. These analogs—such as 5-fluorouracil derivatives, cytarabine, trifluridine, and research probes like EdU and BrdU—mimic natural nucleotides and can substitute for thymidine or cytidine in the DNA strand, resulting in disruption of base pairing, DNA chain elongation arrest, or enzyme inhibition (e.g., thymidylate synthase). The incorporation leads to cytotoxicity exploited in cancer chemotherapy and antiviral therapy, as well as foundational use in cell proliferation assays. However, this pathway encompasses several molecular targets (DNA polymerases, kinases, etc.) and is not a single discrete protein or receptor, but rather a composite therapeutic mechanism involving multiple enzymatic steps. The process is relevant in oncology, virology, and cell biology research, but is not a “canonical target” in the sense of a single, named protein or receptor—it instead describes a drug interaction mechanism spanning many molecular players.

Other names

Pyrimidine analog-nucleotide incorporation pathwayPyrimidine analogs in DNA replicationNucleoside analog-DNA synthesis

Incorporation of nucleotide analog into DNA during replication, leading to DNA chain termination, faulty base pairing, or inhibition of DNA and RNA synthesis. Enzyme inhibition (e.g., thymidylate synthase inhibition by FdUMP, thymidine kinase inhibition). Induction of DNA damage and activation of cell death pathways.