CTP salvage

Definition

Target type: biologicalprocess

Any process which produces cytidine 5'-triphosphate (CTP) from derivatives of it, without de novo synthesis. [GOC:ecd, GOC:jl, PMID:10501935]

CTP salvage is a crucial metabolic pathway that ensures a constant supply of cytidine triphosphate (CTP), an essential nucleotide for DNA and RNA synthesis. Unlike de novo CTP synthesis, which involves a complex multi-step process from simple precursors, salvage pathways utilize pre-existing nucleobases, nucleosides, or nucleotides to generate the desired nucleotide.

In CTP salvage, the primary source of CTP precursors is cytidine, a nucleoside composed of cytosine linked to ribose. This pathway primarily occurs in the cytoplasm and involves two key enzymes:

1. **Cytidine Kinase:** This enzyme catalyzes the phosphorylation of cytidine to cytidine monophosphate (CMP) using ATP as the phosphate donor.
2. **CMP Kinase:** This enzyme further phosphorylates CMP to CDP (cytidine diphosphate) using ATP.
3. **CTP Synthetase:** This enzyme catalyzes the final step, converting CDP to CTP using glutamine as the amino group donor.

The salvage pathway also utilizes other precursors like cytidine 5'-monophosphate (CMP) and cytidine 5'-diphosphate (CDP). These can be directly incorporated into the pathway by CMP kinase and CTP synthetase, respectively.

CTP salvage is highly regulated to maintain cellular CTP homeostasis. Factors influencing this regulation include the availability of precursors, the activity of the enzymes involved, and the overall cellular energy state.

The significance of CTP salvage lies in its ability to efficiently utilize pre-existing nucleobases, conserving metabolic energy and resources. This is particularly crucial during periods of rapid nucleotide demand, like cell growth and division, where de novo synthesis alone might not be sufficient.'
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Proteins (1)

Compounds (2)