GO:0044205 'de novo' UMP biosynthetic process: Pyrimidine Nucleotide Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0044205 'de novo' UMP biosynthetic process describes the chemical reactions and pathways that build uridine monophosphate (UMP) from bicarbonate, beginning with synthesis of (S)-dihydroorotate.
• The pathway is a six-step enzymatic cascade in which the first three steps are catalyzed by a single trifunctional enzyme, CAD, and the terminal steps are completed by UMPS.
• UMP is the parent pyrimidine nucleotide from which CTP, dTMP and RNA pyrimidines are derived, making this pathway essential for nucleic acid synthesis and cell proliferation.
• Cancer cells frequently become addicted to de novo pyrimidine biosynthesis, and this dependency is being exploited as a therapeutic vulnerability in gastric cancer, pancreatic cancer and diffuse midline glioma.
• Physiological levels of uric acid can act as an endogenous inhibitor of UMP synthase, showing that the pathway is sensitive to the metabolic environment.
• In model organisms such as C. elegans, UMP synthesis is connected to programmed cell death, indicating roles beyond simple nucleotide supply.
Description
The Gene Ontology term GO:0044205, 'de novo' UMP biosynthetic process, defines the set of biochemical reactions that produce uridine monophosphate (UMP) from simple precursors, starting with the formation of (S)-dihydroorotate from bicarbonate. UMP is the first fully formed pyrimidine nucleotide and serves as the precursor for all other pyrimidine ribonucleotides and deoxyribonucleotides, so this pathway sits at the intersection of nucleotide metabolism, RNA synthesis and DNA replication. Because proliferating cells must constantly supply pyrimidines for nucleic acids, the de novo UMP pathway is tightly linked to cell growth and division. Researchers study GO:0044205 to understand how metabolic flux through pyrimidine biosynthesis is controlled, how it is rewired in cancer and other diseases, and how it can be targeted pharmacologically. The pathway is also relevant in non-mammalian systems, where it has been connected to developmental and cell death programs. This article summarizes the definition, mechanism, key genes, disease links and experimental approaches for GO:0044205, based on published literature and the QuickGO definition.
'de novo' UMP biosynthetic process At A Glance
| GO ID | GO:0044205 |
|---|---|
| GO term | 'de novo' UMP biosynthetic process |
| Ontology | biological_process |
| Synonym | 'de novo' UMP biosynthesis |
| Definition | The chemical reactions and pathways resulting in the formation of UMP, uridine monophosphate, starting with the synthesis of (S)-dihydroorotate from bicarbonate; UMP biosynthesis may either occur via reduction by quinone, NAD+ or oxygen. |
| Major function | Production of UMP as the parent pyrimidine nucleotide for RNA, DNA and nucleotide sugar metabolism. |
| Key enzymes | CAD (carbamoyl phosphate synthetase II, aspartate transcarbamoylase, dihydroorotase), DHODH, UMPS. |
| Pathway location | Cytosol and mitochondria, with DHODH anchored to the inner mitochondrial membrane. |
| Disease relevance | Cancer, metabolic rewiring, and developmental or cell death programs. |
What Is GO:0044205?
GO:0044205 'de novo' UMP biosynthetic process is the biological process in which cells synthesize UMP from bicarbonate through a series of enzymatic steps, beginning with the production of (S)-dihydroorotate. The pathway proceeds through intermediates such as carbamoyl phosphate, carbamoyl aspartate, dihydroorotate, orotate and orotidine monophosphate, and the final step converts orotidine monophosphate to UMP. The QuickGO definition notes that UMP biosynthesis may occur via reduction by quinone, NAD+ or oxygen, reflecting the use of different electron acceptors by dihydroorotate dehydrogenase in different organisms or conditions. In essence, this term captures the core route by which cells make pyrimidine nucleotides from scratch rather than salvaging them from preformed nucleosides.
Why Is 'de novo' UMP biosynthetic process Important in Cell Biology?
GO:0044205 is important because UMP is the obligate precursor of all pyrimidine nucleotides, and the de novo pathway is the main route for supplying pyrimidines in rapidly dividing cells. Many cancer cells become dependent on this pathway, and inhibiting it can reduce proliferation or trigger cell death, making it a target for drug development. The pathway is also sensitive to the metabolic environment, as shown by the finding that uric acid can inhibit UMP synthase. Understanding GO:0044205 therefore informs cancer metabolism, pharmacology and basic cell biology.
• Provides the pyrimidine nucleotide UMP required for RNA and DNA synthesis.
• Supports rapid proliferation of cancer cells, which often show addiction to de novo pyrimidine biosynthesis.
• Represents a druggable vulnerability in pancreatic cancer and diffuse midline glioma.
• Is regulated by metabolic context, including inhibition of UMP synthase by uric acid.
• Connects nucleotide metabolism to programmed cell death in model organisms.
• Is conserved across plants, animals and microorganisms, allowing comparative studies.
• Can be studied with CRISPR knockout, point mutation and overexpression models of CAD, DHODH and UMPS.
• Informs the design of antimetabolite and targeted therapies that block pyrimidine synthesis.
What Happens During 'de novo' UMP biosynthetic process?
Formation of (S)-dihydroorotate from bicarbonate
In simple terms: The cell first builds a small ring-shaped molecule called dihydroorotate using bicarbonate as a starting material.
The pathway begins with the synthesis of (S)-dihydroorotate from bicarbonate, as stated in the QuickGO definition. In mammalian cells, the first three enzymatic activities are carried by the multifunctional protein CAD: carbamoyl phosphate synthetase II, aspartate transcarbamoylase and dihydroorotase. CAD uses bicarbonate and glutamine to form carbamoyl phosphate, which is then combined with aspartate to produce carbamoyl aspartate, and finally cyclized to dihydroorotate. This early part of the pathway is therefore a committed step for pyrimidine biosynthesis.
Oxidation of dihydroorotate to orotate
In simple terms: Dihydroorotate is then converted into orotate by removing electrons, a reaction that requires a cofactor and an electron acceptor.
Dihydroorotate dehydrogenase (DHODH) catalyzes the oxidation of dihydroorotate to orotate. The QuickGO definition notes that this reduction step may occur via quinone, NAD+ or oxygen, depending on the organism and enzyme. In mammalian cells, DHODH is located on the inner mitochondrial membrane and uses ubiquinone as an electron acceptor, linking pyrimidine synthesis to the respiratory chain. This step is often considered rate-limiting and is a target for inhibitors such as brequinar and teriflunomide.
Conversion of orotate to UMP by UMP synthase
In simple terms: The final steps attach a sugar-phosphate and a base to make UMP, the finished product.
UMP synthase (UMPS) is a bifunctional enzyme that converts orotate to orotidine monophosphate (OMP) and then decarboxylates OMP to UMP. This terminal step completes the de novo pathway and produces the first pyrimidine nucleotide. UMP synthase activity can be inhibited by physiological concentrations of uric acid, revealing a link between purine catabolism and pyrimidine synthesis. The product UMP then serves as a precursor for CTP, dTMP and RNA.
Integration with nucleotide salvage and transport
In simple terms: Cells can also recycle pyrimidines, and the de novo pathway works alongside transport and salvage systems.
Although GO:0044205 specifically covers de novo synthesis, its products and intermediates intersect with nucleoside transport and salvage metabolism. Nucleoside transporters move uridine and other nucleosides across membranes, and salvage enzymes can convert them to UMP, providing an alternative to de novo synthesis. In plants, pyrimidine metabolism is regulated at multiple levels, including feedback inhibition and developmental signals. These connections mean that the contribution of de novo UMP synthesis must be interpreted in the context of the whole nucleotide economy.
Role of UMP in downstream RNA and DNA synthesis
In simple terms: UMP is the raw material for making the pyrimidine building blocks of RNA and DNA.
UMP is phosphorylated to UDP and UTP, which are used directly in RNA synthesis, and UTP is converted to CTP for RNA and phospholipid metabolism. UMP is also a precursor for dTMP via thymidylate synthase, linking de novo pyrimidine synthesis to DNA replication. RNA-specific ribonucleotidyl transferases can add nucleotides to RNA ends, further connecting UMP supply to RNA metabolism. Thus, the de novo UMP pathway supports both transcription and genome duplication.
Connection to cell death and stress responses
In simple terms: When UMP synthesis is disturbed, cells can activate death or stress programs.
In C. elegans, UMP synthesis has been connected to programmed cell death, indicating that pyrimidine metabolism can influence cell survival decisions. In cancer cells, inhibition of de novo pyrimidine biosynthesis can induce stress and reduce viability, especially when salvage pathways are limited. These observations suggest that GO:0044205 is not only a biosynthetic route but also a metabolic node that can trigger cell death when perturbed.
Key Genes Involved in GO:0044205 'de novo' UMP biosynthetic process
The following genes and proteins are central to the de novo UMP biosynthetic process and are commonly studied in this pathway.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CAD | Trifunctional enzyme catalyzing the first three steps of pyrimidine biosynthesis | Target for studying pathway initiation and cancer dependency |
| DHODH | Mitochondrial enzyme oxidizing dihydroorotate to orotate | Rate-limiting step and drug target in cancer and immunology |
| UMPS | Bifunctional enzyme converting orotate to UMP | Terminal step; inhibited by uric acid |
| CTPS1 | Converts UTP to CTP downstream of UMP | Links UMP synthesis to CTP supply |
| CTPS2 | Alternative CTP synthase isoform | Studied in nucleotide metabolism |
| TYMS | Thymidylate synthase using dUMP to make dTMP | Connects UMP to DNA synthesis |
| RRM1 | Ribonucleotide reductase subunit for deoxyribonucleotide synthesis | Downstream of UMP for DNA precursors |
| RRM2 | Ribonucleotide reductase subunit | Downstream of UMP for DNA precursors |
| SLC29A1 | Equilibrative nucleoside transporter | Influences salvage and UMP supply |
| SLC29A2 | Equilibrative nucleoside transporter | Influences salvage and UMP supply |
| UCK1 | Uridine-cytidine kinase | Salvage route to UMP |
| UCK2 | Uridine-cytidine kinase | Salvage route to UMP |
| NR4A1 | Nuclear receptor regulated by UMP | Links UMP to gastric cancer progression |
| UMPS | UMP synthase | Target for uric acid inhibition |
| DHODH | Dihydroorotate dehydrogenase | Target in pancreatic cancer and glioma |
| CAD | Carbamoyl phosphate synthetase II | Addiction marker in diffuse midline glioma |
| ATIC | Bifunctional purine biosynthesis enzyme | Related nucleotide metabolism context |
How Is 'de novo' UMP biosynthetic process Regulated?
The de novo UMP biosynthetic process is regulated at multiple levels. CAD is activated by phosphorylation and by PRPP, and its activity is coordinated with cell cycle progression. DHODH activity depends on the mitochondrial electron transport chain and ubiquinone availability, linking pyrimidine synthesis to cellular respiration. UMP synthase can be inhibited by uric acid, providing a metabolic feedback mechanism. In plants, pyrimidine metabolism is subject to developmental and feedback regulation. In cancer cells, oncogenic signaling can increase flux through the pathway, creating a dependency that can be targeted.
'de novo' UMP biosynthetic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CAD | Diffuse midline glioma addiction to pyrimidine synthesis | CRISPR knockout or point mutation in glioma cell lines |
| DHODH | Pancreatic cancer and pyrimidine plasticity | Knockout and inhibitor studies in pancreatic cancer models |
| UMPS | Metabolic inhibition by uric acid | Point mutation of UMPS to test uric acid binding |
| NR4A1 | Gastric cancer progression regulated by UMP | Overexpression and knockout in gastric cancer cells |
| UMPS | Programmed cell death in C. elegans | Knockout or RNAi in C. elegans |
Cancer metabolism and pyrimidine addiction
Many cancers reprogram nucleotide metabolism to support rapid proliferation. In gastric cancer, UMP functions as an endogenous regulator of NR4A1 and controls cancer progression. Pancreatic cancer models show that targeting plasticity in the pyrimidine synthesis pathway can potentiate macrophage-mediated phagocytosis. Diffuse midline glioma displays a druggable addiction to de novo pyrimidine biosynthesis, with CAD and DHODH as key nodes. These findings position GO:0044205 as a therapeutic target in multiple tumor types.
Metabolic inhibition by uric acid
Physiological concentrations of uric acid can inhibit UMP synthase, revealing an endogenous mechanism that links purine catabolism to pyrimidine synthesis. This regulation may influence how cells respond to changes in purine levels and could be relevant in metabolic disorders.
Cell death and developmental programs
In C. elegans, UMP synthesis connects nucleotide metabolism to programmed cell death, suggesting that this pathway can influence developmental cell death decisions. This expands the biological roles of GO:0044205 beyond biosupply and into cell fate regulation.
Plant and microbial pyrimidine metabolism
In plants, pyrimidine metabolism is regulated in response to developmental and environmental cues, and de novo UMP synthesis is part of this network. Nucleoside transport and salvage also contribute to UMP pools in plants and other organisms. Comparative studies can reveal conserved and divergent features of GO:0044205.
From 'de novo' UMP biosynthetic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is CAD required for cancer cell proliferation? | CRISPR knockout of CAD in cancer cell lines |
| Does a point mutation in DHODH alter enzyme activity? | Point-mutation knock-in of DHODH |
| Can UMP synthase be inhibited by uric acid? | Knock-in of tagged UMPS and biochemical assays |
| Does overexpression of NR4A1 affect gastric cancer growth? | Overexpression of NR4A1 in gastric cancer cells |
| Is UMP synthesis required for cell death in C. elegans? | Knockout or RNAi of UMP pathway genes in C. elegans |
| How does pyrimidine pathway plasticity affect macrophage phagocytosis? | CRISPR library screening in pancreatic cancer models |
How to Study the 'de novo' UMP biosynthetic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Stable isotope tracing | Flux through de novo UMP synthesis | Cancer metabolism studies |
| Enzyme activity assay | CAD, DHODH or UMPS catalytic activity | Inhibitor testing |
| CRISPR knockout screen | Genes required for proliferation | Identify pathway dependencies |
| RNA-seq | Transcriptional changes after perturbation | Pathway regulation |
| Proteomics | Protein abundance and modifications | Enzyme expression |
| Metabolomics | UMP and intermediate levels | Pathway flux and inhibition |
| Cell viability assay | Proliferation and survival | Drug response |
| Imaging | Localization of pathway enzymes | Mitochondrial DHODH |
Metabolic flux analysis
Stable isotope tracing with labeled bicarbonate or glutamine can measure flux through the de novo UMP pathway. This approach quantifies how much UMP is produced de novo versus salvaged.
Enzyme activity assays
In vitro assays for CAD, DHODH and UMPS can measure catalytic activity and inhibition, for example by uric acid. These assays are often combined with recombinant proteins or cell lysates.
CRISPR screening
Genome-wide CRISPR knockout screens can identify genes required for proliferation in the context of pyrimidine synthesis. Such screens have revealed dependencies on CAD and DHODH in cancer models.
RNA sequencing and proteomics
RNA-seq and proteomics can measure expression changes in pathway genes after perturbation. These methods help link UMP synthesis to downstream transcriptional programs.
How CRISPR Can Be Used to Study GO:0044205 'de novo' UMP biosynthetic process
Knockout
CRISPR knockout of CAD, DHODH or UMPS can abolish de novo UMP synthesis and reveal whether cells depend on this pathway for growth. Knockout models are useful for testing salvage compensation and drug sensitivity.
Point Mutation
Point mutations can be introduced into DHODH or UMPS to test catalytic residues, inhibitor binding or regulation by uric acid. Such models help distinguish enzymatic functions from scaffolding roles.
Knock-in
Knock-in of tagged versions of CAD, DHODH or UMPS allows localization and interaction studies. Tagged knock-in can also be used to monitor pathway dynamics in live cells.
Overexpression
Overexpression of NR4A1 or pathway enzymes can test sufficiency for proliferation or metabolic rewiring. Overexpression models are often combined with metabolic flux analysis.
How EDITGENE Supports 'de novo' UMP biosynthetic process Research
Researchers studying 'de novo' UMP biosynthetic process-related genes often need to determine whether a candidate gene is causally involved in pathway flux, cell proliferation or disease phenotypes. EDITGENE provides CRISPR-based cell models and screening services to support these studies.
Contact EDITGENE today to design your custom CRISPR model for 'de novo' UMP biosynthetic process research.
Related Products
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|---|
Frequently Asked Questions About 'de novo' UMP biosynthetic process
What is GO:0044205 'de novo' UMP biosynthetic process?
It is the biological process that produces UMP from bicarbonate through a series of enzymatic steps, starting with (S)-dihydroorotate synthesis.
What genes are involved in 'de novo' UMP biosynthetic process?
Key genes include CAD, DHODH and UMPS, which catalyze the main steps of the pathway.
Why is UMP synthesis important for cancer?
Many cancer cells depend on de novo pyrimidine synthesis for proliferation, making the pathway a therapeutic target.
How is 'de novo' UMP biosynthetic process regulated?
It is regulated by enzyme expression, feedback inhibition, mitochondrial respiration and metabolites such as uric acid.
What is the role of DHODH in UMP synthesis?
DHODH oxidizes dihydroorotate to orotate and is a rate-limiting enzyme in the pathway.
Can UMP synthase be inhibited?
Yes, UMP synthase can be inhibited by physiological concentrations of uric acid.
What diseases are linked to UMP synthesis?
Cancer, metabolic disorders and developmental cell death programs have been linked to this pathway.
How do researchers study 'de novo' UMP biosynthetic process?
They use metabolic flux analysis, enzyme assays, CRISPR screens, RNA-seq and proteomics.
Is UMP synthesis conserved in plants?
Yes, pyrimidine metabolism including de novo UMP synthesis is present in plants and is regulated developmentally.
What CRISPR models are used for UMP pathway studies?
Knockout, point mutation, knock-in and overexpression models of CAD, DHODH and UMPS are commonly used.
Conclusion
GO:0044205 'de novo' UMP biosynthetic process is a central metabolic pathway that supplies UMP for RNA and DNA synthesis and is frequently rewired in cancer and other diseases. Its key enzymes CAD, DHODH and UMPS are druggable nodes and are actively studied with CRISPR models and metabolic assays. Understanding this pathway provides insights into cell proliferation, metabolic regulation and therapeutic opportunities.
References
- 1. Cai G et al.. 2025. UMP functions as an endogenous regulator of NR4A1 to control gastric cancer progression.. Mol Cell 85(23):4347-4364.e12 PMID: 41270758
- 2. Cantor JR et al.. 2017. Physiologic Medium Rewires Cellular Metabolism and Reveals Uric Acid as an Endogenous Inhibitor of UMP Synthase.. Cell 169(2):258-272.e17 PMID: 28388410
- 3. Zhao J et al.. 2025. Targeting plasticity in the pyrimidine synthesis pathway potentiates macrophage-mediated phagocytosis in pancreatic cancer models.. J Clin Invest 135(22) PMID: 41243973
- 4. Pal S et al.. 2022. A druggable addiction to de novo pyrimidine biosynthesis in diffuse midline glioma.. Cancer Cell 40(9):957-972.e10 PMID: 35985342
- 5. Möhlmann T et al.. 2010. Nucleoside transport and associated metabolism.. Plant Biol (Stuttg) 12 Suppl 1:26-34 PMID: 20712618
- 6. Martin G et al.. 2007. RNA-specific ribonucleotidyl transferases.. RNA 13(11):1834-49 PMID: 17872511
- 7. Jiang HS et al.. 2026. Uridine 5'-monophosphate (UMP) synthesis connects nucleotide metabolism to programmed cell death in C. elegans.. Cell Death Differ 33(1):25-37 PMID: 40903566
- 8. Kafer C et al.. 2004. Regulation of pyrimidine metabolism in plants.. Front Biosci 9:1611-25 PMID: 14977572
