GO:0004170 dUTP diphosphatase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004170 dUTP diphosphatase activity catalyzes the hydrolysis of dUTP to dUMP and diphosphate, a reaction that both prevents uracil misincorporation into DNA and supplies dUMP for thymidylate synthesis.
• The reaction is Mg2+-dependent and proceeds through a nucleophilic attack on the alpha-phosphate of dUTP, releasing pyrophosphate.
• dUTP diphosphatase activity is found in all three domains of life, with bifunctional enzymes in some archaea and viruses that combine deaminase and diphosphatase activities.
• Loss of dUTPase activity leads to elevated dUTP pools, uracil misincorporation, DNA fragmentation, and cell death, making it a target in cancer and infectious disease research.
• Key genes encoding dUTP diphosphatase activity include DUT in humans, dut in E. coli, and viral homologs in baculoviruses and herpesviruses.
• CRISPR knockout, point mutation, and overexpression models are essential to dissect the role of dUTPase in nucleotide metabolism, genome stability, and drug response.
Description
dUTP diphosphatase activity (GO:0004170) is a molecular function that catalyzes the hydrolysis of deoxyuridine triphosphate (dUTP) to deoxyuridine monophosphate (dUMP) and diphosphate. This reaction is critical for maintaining the balance of nucleotide pools and preventing the misincorporation of uracil into DNA, which can lead to mutagenesis and cell death. The enzyme responsible, dUTPase, is highly conserved across evolution, with bifunctional variants in some archaea and viruses that also possess deaminase activity. Researchers study this activity to understand DNA repair, thymidylate biosynthesis, and the mechanisms of antiviral and anticancer drugs. The kinetic properties of dUTPases from bacterial pathogens such as Campylobacter jejuni have been characterized, revealing dimeric forms with both dUTPase and dUDPase activities. In baculoviruses, genome sequencing has uncovered insights into the evolution of nucleotide metabolism enzymes, including dUTPase homologs. Understanding GO:0004170 is therefore essential for dissecting nucleotide metabolism, genome stability, and host-pathogen interactions.
dUTP diphosphatase activity At A Glance
| GO ID | GO:0004170 |
|---|---|
| GO term | dUTP diphosphatase activity |
| Ontology | molecular_function |
| Synonym | dUTPase activity; dUTP nucleotidohydrolase activity; dUTP pyrophosphatase activity; deoxyuridine-triphosphatase activity; desoxyuridine 5'-triphosphatase activity; desoxyuridine 5'-triphosphate nucleotidohydrolase activity |
| Definition | Catalysis of the reaction: dUTP + H2O = dUMP + H+ + diphosphate. |
| Major function | Hydrolysis of dUTP to dUMP and diphosphate, preventing uracil misincorporation into DNA and providing dUMP for thymidylate synthesis. |
| Cofactors | Mg2+ (required for catalysis) |
| Subcellular location | Cytoplasm, nucleus, mitochondria (varies by organism) |
| EC number | 3.6.1.23 |
What Is GO:0004170?
dUTP diphosphatase activity (GO:0004170) is defined as the catalysis of the reaction: dUTP + H2O = dUMP + H+ + diphosphate. In other words, it is an enzyme activity that removes two phosphate groups from dUTP, producing dUMP and pyrophosphate. This activity is synonymous with dUTPase, dUTP nucleotidohydrolase, and dUTP pyrophosphatase, among other names. It belongs to the molecular_function ontology and is essential for nucleotide metabolism and DNA integrity.
Why Is dUTP diphosphatase activity Important in Cell Biology?
dUTP diphosphatase activity is crucial for maintaining genomic integrity by keeping cellular dUTP levels low, thereby preventing uracil misincorporation into DNA. This activity also provides dUMP, the substrate for thymidylate synthase, linking it to DNA synthesis and repair. Dysregulation of dUTPase has been implicated in cancer, where elevated activity can confer resistance to antifolate drugs, and in viral infections, where viral dUTPases are potential drug targets. Understanding this activity is therefore important for developing therapeutic strategies against cancer and infectious diseases.
• Prevents uracil misincorporation into DNA, reducing mutagenesis and DNA damage.
• Supplies dUMP for thymidylate synthesis, supporting DNA replication and repair.
• Modulates sensitivity to anticancer and antiviral drugs that target nucleotide metabolism.
• Essential for bacterial pathogen survival, making it a potential antibiotic target.
• Viral dUTPases, such as those in baculoviruses, influence host range and pathogenesis.
• Bifunctional dUTPases in archaea and viruses reveal evolutionary links between deaminase and diphosphatase activities.
• Plays a role in mitochondrial DNA maintenance and apoptosis.
• Serves as a model system for studying enzyme kinetics and allosteric regulation.
Molecular Mechanism of dUTP diphosphatase activity
Substrate Binding and Catalysis
In simple terms: The enzyme grabs dUTP and uses water to split off two phosphates.
dUTP diphosphatase binds dUTP in its active site, where a conserved water molecule is activated for nucleophilic attack on the alpha-phosphate. This leads to the release of diphosphate and the formation of dUMP. The reaction requires Mg2+ ions, which stabilize the transition state and neutralize negative charges on the phosphate groups. Kinetic studies of the dimeric dUTPase-dUDPase from Campylobacter jejuni have shown that the enzyme can also hydrolyze dUDP, albeit with different efficiency.
Cofactors and Metal Ion Dependence
In simple terms: Magnesium helps the enzyme work by holding the phosphate groups in place.
dUTP diphosphatase activity is strictly dependent on divalent metal ions, typically Mg2+. The metal ion coordinates with the phosphate groups of dUTP and with conserved aspartate residues in the active site, facilitating the nucleophilic attack by water. In some organisms, the enzyme may also utilize other divalent cations such as Mn2+ or Co2+, but Mg2+ is the most physiologically relevant.
Enzyme Structure and Oligomeric States
In simple terms: The enzyme can be a single unit or a pair, and sometimes it has two different jobs.
dUTP diphosphatases exist in various oligomeric forms. The human enzyme is a monomer, while bacterial and viral enzymes are often homotrimers or dimers. The Campylobacter jejuni enzyme is a dimer that exhibits both dUTPase and dUDPase activities. In Methanococcus jannaschii, the dCTP deaminase is bifunctional, possessing both deaminase and diphosphatase activities, indicating that some archaeal enzymes combine two steps of nucleotide metabolism. Baculovirus genomes encode dUTPase homologs that may have evolved distinct roles in viral replication.
Regulation and Inhibition
In simple terms: The enzyme can be turned on or off by other molecules, and drugs can block it.
dUTP diphosphatase activity is regulated at multiple levels, including transcriptional control and post-translational modifications. In cancer cells, overexpression of dUTPase can lead to resistance to thymidylate synthase inhibitors such as 5-fluorouracil. Inhibitors of dUTPase, such as those based on nucleotide analogs, have been explored as potential antimicrobial and anticancer agents. The dimeric dUTPase-dUDPase from Campylobacter jejuni is inhibited by dUDP and other nucleotide analogs, providing insights into active site specificity.
Key Genes Involved in GO:0004170 dUTP diphosphatase activity
The following genes encode proteins with dUTP diphosphatase activity or are directly involved in its regulation and function.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DUT (human) | Encodes dUTPase, hydrolyzes dUTP to dUMP | Target for cancer therapy; involved in drug resistance |
| dut (E. coli) | Essential for DNA integrity | Model for studying nucleotide metabolism and antibiotic targets |
| DCD (Methanococcus jannaschii) | Bifunctional dCTP deaminase/dUTPase | Evolutionary link between deaminase and diphosphatase |
| Baculovirus dUTPase | Viral dUTPase homolog | Role in viral replication and host range |
| C. jejuni dUTPase | Dimeric dUTPase-dUDPase | Kinetic and inhibition studies |
| Herpesvirus dUTPase | Viral dUTPase | Potential antiviral target |
| Vaccinia virus dUTPase | Viral dUTPase | Role in poxvirus replication |
| Human DUT isoforms | Nuclear and mitochondrial dUTPase | Compartment-specific functions |
| Thymidylate synthase (TYMS) | Produces dTMP from dUMP | Linked to dUTPase in nucleotide metabolism |
| Dihydropyrimidinase (DPYS) | Pyrimidine degradation | Indirectly affects dUTP pools |
| Uracil-DNA glycosylase (UNG) | Removes uracil from DNA | Works with dUTPase to maintain genome stability |
| Ribonucleotide reductase (RNR) | Produces dUTP | Regulates dUTP levels |
| dCMP deaminase | Produces dUMP | Alternative route to dUMP |
| Nucleoside diphosphate kinase (NDK) | Phosphorylates dUDP to dUTP | Balances nucleotide pools |
| APOBEC3 | Cytidine deaminase | Indirectly affects dUTP incorporation |
| SAMHD1 | Regulates dNTP pools | Links to dUTPase in HIV restriction |
| p53 | Regulates DUT expression | Stress response and DNA repair |
How Is dUTP diphosphatase activity Regulated?
dUTP diphosphatase activity is regulated at transcriptional, post-transcriptional, and post-translational levels. In human cells, the DUT gene is induced by DNA damage and replication stress, partly through p53-dependent pathways. The enzyme can be phosphorylated, affecting its stability and subcellular localization. In bacteria, dUTPase expression is controlled by the SOS response and nucleotide pool imbalances. Viral dUTPases are often expressed late in infection to support viral DNA replication.
dUTP diphosphatase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DUT | Cancer drug resistance | Knockout and overexpression in cancer cell lines |
| Herpesvirus dUTPase | Viral replication | Viral infection models with dUTPase inhibitors |
| C. jejuni dUTPase | Bacterial infection | Bacterial knockout and inhibitor assays |
| DCD | Archaeal nucleotide metabolism | Bifunctional enzyme studies |
| Baculovirus dUTPase | Insect host range | Viral genome editing and infection |
Cancer and Drug Resistance
Overexpression of dUTPase (DUT) is associated with resistance to thymidylate synthase inhibitors such as 5-fluorouracil and methotrexate in cancer cells. Elevated dUTPase activity reduces dUTP pools and limits the incorporation of uracil analogs into DNA, thereby diminishing drug efficacy. Targeting dUTPase is therefore a potential strategy to overcome chemoresistance.
Viral Infections
Many viruses, including herpesviruses and baculoviruses, encode their own dUTPases that are essential for viral DNA replication and pathogenesis. These viral enzymes differ structurally from human dUTPase, making them attractive targets for antiviral drugs with reduced host toxicity.
Bacterial Pathogenesis
dUTPase is essential for the survival of bacterial pathogens such as Campylobacter jejuni, where it maintains DNA integrity under stress. Inhibitors of bacterial dUTPase could serve as novel antibiotics, especially against drug-resistant strains.
From dUTP diphosphatase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does DUT loss affect cancer cell survival? | CRISPR knockout in HeLa or HCT116 cells |
| How does dUTPase overexpression alter drug sensitivity? | Overexpression in cancer cell lines |
| What is the role of viral dUTPase in replication? | Knockout of viral dUTPase in baculovirus |
| Can point mutations in DUT alter catalytic activity? | CRISPR point mutation knock-in in human cells |
| How does dUTPase localize in cells? | Tagged knock-in with fluorescent protein |
| What are the kinetic properties of bacterial dUTPase? | Purified recombinant enzyme assays |
How to Study the dUTP diphosphatase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Enzymatic assay | dUTP hydrolysis rate | Kinetic characterization |
| CRISPR knockout | Gene function loss | Cell survival and DNA damage |
| CRISPR point mutation | Specific amino acid function | Active site analysis |
| RNA-seq | Transcriptional changes | Global response to dUTPase loss |
| Metabolomics | Nucleotide pool levels | dUTP/dUMP quantification |
| Western blot | Protein expression | Overexpression validation |
| Comet assay | DNA fragmentation | Uracil misincorporation detection |
| X-ray crystallography | 3D protein structure | Inhibitor design |
Enzymatic Assays
dUTP diphosphatase activity is typically measured using spectrophotometric or radiometric assays that monitor the conversion of dUTP to dUMP. Kinetic parameters such as Km and Vmax are determined using purified enzyme or cell lysates. Inhibition studies with nucleotide analogs help identify potential drugs.
CRISPR-Cas9 Genome Editing
CRISPR knockout, point mutation, and knock-in models are used to study the function of dUTPase genes in cells. Knockout of DUT leads to elevated dUTP and uracil misincorporation, which can be assessed by comet assay or uracil-DNA glycosylase assays. Point mutations in the active site can dissect catalytic residues.
Omics Approaches
RNA-seq and proteomics can reveal changes in gene expression and protein levels upon dUTPase perturbation. Metabolomics quantifies nucleotide pools, including dUTP and dUMP, providing direct evidence of enzyme activity. These methods are useful for understanding global cellular responses.
Structural Biology
X-ray crystallography and cryo-EM have been used to determine the structures of dUTPases from various organisms, revealing active site architecture and metal coordination. These structures guide the design of inhibitors.
How CRISPR Can Be Used to Study GO:0004170 dUTP diphosphatase activity
Knockout
CRISPR knockout of DUT or viral dUTPase genes eliminates enzyme activity, leading to dUTP accumulation and uracil misincorporation. This model is used to study DNA repair, cell cycle arrest, and apoptosis. Knockout of bacterial dUTPase can reveal essentiality and antibiotic targets.
Point Mutation
CRISPR point mutation introduces specific amino acid substitutions in the dUTPase active site, allowing researchers to dissect catalytic residues and metal-binding sites. Such models help validate structural predictions and kinetic data.
Knock-in
Knock-in of tagged dUTPase (e.g., GFP or FLAG) enables live-cell imaging and proteomic analysis. This approach is useful for studying subcellular localization and interaction partners. Knock-in of disease-associated mutations can model human disorders.
Overexpression
CRISPR activation or lentiviral overexpression of DUT increases dUTPase levels, mimicking drug-resistant cancer phenotypes. These models are used to test sensitivity to thymidylate synthase inhibitors and other chemotherapeutics.
How EDITGENE Supports dUTP diphosphatase activity Research
Researchers studying dUTP diphosphatase activity-related genes often need to determine whether a candidate gene is causally involved in nucleotide metabolism, DNA repair, or drug resistance. EDITGENE provides comprehensive CRISPR-based services to generate knockout, point mutation, knock-in, and overexpression cell models, as well as library screening and bioinformatics support, enabling precise functional studies of GO:0004170.
Contact EDITGENE today to design your custom CRISPR model for dUTP diphosphatase activity research.
Frequently Asked Questions About dUTP diphosphatase activity
What is dUTP diphosphatase activity?
dUTP diphosphatase activity (GO:0004170) is the enzyme activity that catalyzes the hydrolysis of dUTP to dUMP and diphosphate, preventing uracil misincorporation into DNA.
What genes are involved in dUTP diphosphatase activity?
Key genes include DUT in humans, dut in E. coli, and viral homologs in baculoviruses and herpesviruses.
What is the function of dUTPase?
dUTPase maintains low dUTP levels and provides dUMP for thymidylate synthesis, supporting DNA integrity and replication.
How is dUTP diphosphatase activity regulated?
It is regulated transcriptionally by p53 and other factors, and post-translationally by phosphorylation.
What diseases are associated with dUTPase?
dUTPase is linked to cancer drug resistance, viral infections, and bacterial pathogenesis.
What are the substrates of dUTP diphosphatase?
The primary substrate is dUTP, but some enzymes also hydrolyze dUDP.
What cofactors are required for dUTP diphosphatase activity?
Mg2+ is required for catalysis.
How can I study dUTP diphosphatase activity in the lab?
Enzymatic assays, CRISPR knockout, metabolomics, and structural biology are common approaches.
What is the role of dUTPase in cancer?
Overexpression of dUTPase can confer resistance to thymidylate synthase inhibitors like 5-fluorouracil.
Are there bifunctional dUTPases?
Yes, some archaeal and viral enzymes combine deaminase and diphosphatase activities.
Conclusion
dUTP diphosphatase activity (GO:0004170) is a fundamental enzymatic function that safeguards DNA integrity and supports nucleotide metabolism. Its roles in cancer drug resistance, viral replication, and bacterial pathogenesis make it a compelling target for therapeutic development. CRISPR-based models and advanced omics technologies are essential tools for dissecting its mechanism and regulation. EDITGENE offers comprehensive services to accelerate research on this critical enzyme.
References
- 1. Li H et al.. 2003. The Methanococcus jannaschii dCTP deaminase is a bifunctional deaminase and diphosphatase.. J Biol Chem 278(13):11100-6 PMID: 12538648
- 2. Ardisson-Araújo DM et al.. 2016. Genome sequence of Perigonia lusca single nucleopolyhedrovirus: insights into the evolution of a nucleotide metabolism enzyme in the family Baculoviridae.. Sci Rep 6:24612 PMID: 27273152
- 3. Musso-Buendía JA et al.. 2009. Kinetic properties and inhibition of the dimeric dUTPase-dUDPase from Campylobacter jejuni.. J Enzyme Inhib Med Chem 24(1):111-6 PMID: 18608754
