GO:0047453 ATP-dependent NAD(P)H-hydrate dehydratase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0047453 describes the ATP-dependent dehydratase activity that converts (6S)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide adenine dinucleotide to NAD(P)H, consuming ATP and releasing ADP, H+ and phosphate.
• This activity is part of the NAD(P)H-hydrate repair pathway, which removes abnormal hydrated forms of NADH and NADPH that can accumulate under stress and interfere with redox metabolism.
• In Bacillus subtilis, loss of NAD(P)H-hydrate dehydratase impairs stress adaptation, demonstrating a physiological role in bacterial survival.
• In 3T3-L1 preadipocytes, suppression of ATP-dependent (S)-NAD(P)H-hydrate dehydratase causes excessive NADHX accumulation and inhibits adipocyte differentiation.
• The enzyme was initially identified through metabolite cocktail screening, highlighting the power of functional metabolomics for assigning unknown protein functions.
• Proteomic studies of keratoconus tear samples have detected this enzyme among differentially expressed proteins, suggesting potential relevance in ocular surface biology.
Description
ATP-dependent NAD(P)H-hydrate dehydratase activity (GO:0047453) is a molecular function that catalyzes the ATP-dependent dehydration of (6S)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide adenine dinucleotide to yield NAD(P)H, ADP, H+ and phosphate. This activity is essential for repairing hydrated nicotinamide cofactors, which can form spontaneously and impair cellular redox reactions. The enzyme belongs to the NAD(P)H-hydrate repair system, a conserved metabolic safeguard in bacteria, plants and animals. Researchers study GO:0047453 because it links cofactor homeostasis to stress responses, metabolic regulation and cell differentiation. In Bacillus subtilis, the dehydratase is required for efficient adaptation to stress conditions, and its absence leads to accumulation of abnormal NADH forms. In mammalian adipocytes, suppression of the enzyme increases NADHX levels and blocks differentiation, indicating a role in metabolic programming. The function was first assigned to a previously unknown protein using metabolite cocktail screening, illustrating how functional annotation can be driven by metabolomic approaches. Despite its importance, the enzyme remains understudied in human disease contexts. Proteomic profiling of tear samples from keratoconus patients identified the protein among differentially expressed candidates, suggesting possible involvement in corneal biology. Understanding GO:0047453 therefore requires integrating biochemical, genetic and omics approaches to reveal how this repair activity contributes to health and disease.
ATP-dependent NAD(P)H-hydrate dehydratase activity At A Glance
| GO ID | GO:0047453 |
|---|---|
| GO term | ATP-dependent NAD(P)H-hydrate dehydratase activity |
| Ontology | molecular_function |
| Synonym | (6S)-beta-6-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine-dinucleotide hydro-lyase (ATP-hydrolysing); ATP-dependent H4NAD(P)OH dehydratase activity; reduced nicotinamide adenine dinucleotide hydrate dehydratase activity |
| Major function | Repairs hydrated NAD(P)H cofactors by ATP-dependent dehydration, restoring NAD(P)H for redox reactions |
| Reaction | (6S)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide adenine dinucleotide + ATP = ADP + H+ + NAD(P)H + phosphate |
| Cofactor | ATP is required as a phosphoryl donor; the reaction also involves a divalent metal ion in some homologs |
| Subcellular location | Cytoplasm and mitochondria in eukaryotes; cytosol in bacteria |
| Physiological context | Stress adaptation in Bacillus subtilis; adipocyte differentiation in 3T3-L1 cells |
What Is GO:0047453?
GO:0047453, ATP-dependent NAD(P)H-hydrate dehydratase activity, is defined as the catalysis of the reaction: (6S)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide adenine dinucleotide + ATP = ADP + H+ + NAD(P)H + phosphate. In other words, it is an enzyme activity that uses ATP to remove a water molecule from a hydrated form of NADH or NADPH, regenerating the normal cofactor. This activity is also known as ATP-dependent H4NAD(P)OH dehydratase or reduced nicotinamide adenine dinucleotide hydrate dehydratase.
Why Is ATP-dependent NAD(P)H-hydrate dehydratase activity Important in Cell Biology?
GO:0047453 is important because it maintains the pool of functional NAD(P)H by repairing spontaneous hydration products that would otherwise inhibit dehydrogenases and disrupt redox balance. This repair activity supports stress survival in bacteria and metabolic differentiation in mammalian cells, and its dysfunction has been linked to accumulation of toxic NADHX. The enzyme was identified through innovative metabolite screening, underscoring its relevance to functional genomics and metabolomics. Additionally, its detection in keratoconus tear proteomes suggests potential roles in human ocular pathology.
• Maintains NAD(P)H homeostasis by removing inhibitory hydrated adducts.
• Supports bacterial stress adaptation, as shown in Bacillus subtilis.
• Regulates adipocyte differentiation in 3T3-L1 preadipocytes.
• Prevents excessive NADHX accumulation that can impair metabolism.
• Provides a model for functional assignment of unknown proteins via metabolite screening.
• May be relevant to ocular surface diseases such as keratoconus.
• Represents a conserved metabolic repair mechanism across species.
• Offers a target for metabolic engineering and antimicrobial strategies.
• Connects cofactor repair to cell fate decisions.
• Can be studied using proteomics and metabolomics workflows.
What Happens During ATP-dependent NAD(P)H-hydrate dehydratase activity?
Substrate recognition and binding
In simple terms: The enzyme grabs the damaged NADH molecule and ATP.
The enzyme binds (6S)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide adenine dinucleotide, a hydrated form of NADH or NADPH, along with ATP. Structural and biochemical studies indicate that the active site accommodates the hydrated nicotinamide ring and positions ATP for phosphoryl transfer.
ATP-dependent dehydration
In simple terms: ATP provides energy to remove water from the damaged cofactor.
ATP hydrolysis drives the removal of a water molecule from the hydrated nicotinamide ring, converting it back to the normal NAD(P)H form. The reaction releases ADP, inorganic phosphate and a proton, as summarized in the GO definition.
Product release and cofactor recycling
In simple terms: The repaired NADH is released for use in metabolism.
After dehydration, NAD(P)H is released and can participate in redox reactions, while ADP and phosphate are recycled. This step restores the cellular pool of reducing equivalents and prevents inhibition of dehydrogenases by hydrated adducts.
Physiological consequences
In simple terms: Without this repair, cells accumulate toxic molecules and malfunction.
In Bacillus subtilis, loss of the dehydratase leads to impaired stress adaptation, likely due to accumulation of NADHX. In 3T3-L1 cells, suppression of the enzyme increases NADHX and blocks adipocyte differentiation, demonstrating a role in cell fate.
Key Genes Involved in GO:0047453 ATP-dependent NAD(P)H-hydrate dehydratase activity
The following genes and proteins are directly or indirectly associated with ATP-dependent NAD(P)H-hydrate dehydratase activity, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NAXD (CARKD) | Encodes ATP-dependent NAD(P)H-hydrate dehydratase in humans | Studied for its role in NADHX repair and metabolic stress |
| NAXE (AIBP) | Encodes a related epimerase involved in NAD(P)H repair | Potential functional partner in cofactor homeostasis |
| NudC | NADH pyrophosphatase that may produce NADHX | Contributes to NADHX formation under stress |
| NudF | NADHX epimerase in Bacillus subtilis | Works with dehydratase in the repair pathway |
| YjeF | Bacterial homolog of NAD(P)H-hydrate dehydratase | Model for stress adaptation studies |
| YxkO | Bacillus subtilis NAD(P)H-hydrate dehydratase | Required for stress survival |
| PPCDC | Phosphopantothenoylcysteine decarboxylase, unrelated but detected in screens | Control for metabolite screening |
| GAPDH | Glycolytic enzyme sensitive to NADHX inhibition | Downstream target of repair activity |
| LDHA | Lactate dehydrogenase, NADH-dependent | Affected by NADHX accumulation |
| SIRT1 | NAD+-dependent deacetylase | Indirectly linked to NAD(P) metabolism |
| PPARγ | Adipogenic transcription factor | Differentiation blocked by NADHX accumulation |
| C/EBPα | Adipogenic transcription factor | Downstream of NADHX effects |
| ACACA | Acetyl-CoA carboxylase, NADPH-dependent | Potential target of NADPHX inhibition |
| FASN | Fatty acid synthase, NADPH-dependent | May be impacted by NADPHX |
| SCD1 | Stearoyl-CoA desaturase, NADH-dependent | Lipid metabolism link |
| KRT12 | Keratoconus-associated keratin | Detected alongside dehydratase in tear proteomics |
| ALDH3A1 | Aldehyde dehydrogenase, NAD(P)+-dependent | Oxidative stress link in cornea |
| TXN | Thioredoxin, redox protein | Redox context in keratoconus |
How Is ATP-dependent NAD(P)H-hydrate dehydratase activity Regulated?
The expression and activity of ATP-dependent NAD(P)H-hydrate dehydratase are regulated at multiple levels. In Bacillus subtilis, the enzyme is induced under stress conditions, likely through stress-responsive sigma factors. In mammalian cells, suppression of the enzyme by siRNA increases NADHX levels, indicating that its activity is necessary to prevent accumulation of hydrated cofactors. The enzyme may also be regulated by metabolite availability, as ATP and NAD(P)H levels influence its catalytic cycle. However, specific transcriptional regulators or post-translational modifications remain largely uncharacterized.
ATP-dependent NAD(P)H-hydrate dehydratase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NAXD | Metabolic stress, adipocyte differentiation | 3T3-L1 knockout or knockdown |
| YxkO | Bacterial stress adaptation | Bacillus subtilis deletion mutant |
| NAXE | NAD(P)H repair deficiency | Human cell lines with siRNA |
| KRT12 | Keratoconus | Tear proteomics and corneal epithelial cells |
| ALDH3A1 | Oxidative stress in cornea | Corneal cell culture |
Metabolic and differentiation disorders
Dysregulation of ATP-dependent NAD(P)H-hydrate dehydratase activity can lead to excessive NADHX accumulation, which inhibits adipocyte differentiation in 3T3-L1 cells. This suggests that impaired repair of hydrated cofactors may contribute to metabolic disorders characterized by altered adipogenesis, such as obesity and insulin resistance.
Bacterial stress and infection
In Bacillus subtilis, loss of the dehydratase impairs stress adaptation, reducing survival under adverse conditions. This raises the possibility that targeting this enzyme could weaken bacterial stress responses, though direct links to human infection remain to be established.
Ocular surface pathology
Proteomic analysis of tear samples from patients with low-grade keratoconus identified the dehydratase among differentially expressed proteins. While the functional significance is unclear, it suggests a potential role in corneal homeostasis and disease.
From ATP-dependent NAD(P)H-hydrate dehydratase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of NAXD affect adipocyte differentiation? | NAXD knockout 3T3-L1 cells |
| Does YxkO deletion impair stress survival? | Bacillus subtilis yxkO deletion strain |
| Can point mutations in the active site abolish dehydratase activity? | Recombinant NAXD with site-directed mutations |
| Does overexpression of NAXD protect against NADHX toxicity? | NAXD-overexpressing mammalian cells |
| Is NAXD tagged for localization studies? | Knock-in of fluorescent tag at endogenous locus |
| Does NAXD interact with other repair enzymes? | Co-immunoprecipitation from tagged knock-in cells |
How to Study the ATP-dependent NAD(P)H-hydrate dehydratase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Metabolite cocktail screening | Enzymatic activity against diverse metabolites | Functional assignment of unknown proteins |
| LC-MS/MS metabolomics | NADHX and NAD(P)H levels | Quantifying repair activity in cells |
| siRNA knockdown | Gene silencing effects | Testing loss-of-function in 3T3-L1 cells |
| Bacterial deletion mutants | Stress survival | Assessing yxkO role in Bacillus subtilis |
| Tear proteomics | Protein expression changes | Biomarker discovery in keratoconus |
| Enzyme kinetics | Catalytic parameters | Characterizing recombinant enzyme |
| Site-directed mutagenesis | Active site residues | Mechanistic studies |
| Co-immunoprecipitation | Protein-protein interactions | Identifying repair complex partners |
Metabolite screening and enzymology
Metabolite cocktail screening was used to identify the function of an unknown protein as an ATP-dependent NAD(P)H-hydrate dehydratase. This approach involves incubating candidate proteins with diverse metabolites and monitoring consumption or production by mass spectrometry. Enzymatic assays can then measure the conversion of hydrated NADH to NADH in the presence of ATP.
Proteomics and expression analysis
Proteomic profiling of tear samples from keratoconus patients revealed differential expression of the dehydratase, demonstrating the utility of clinical proteomics for discovering disease associations. Similar workflows can be applied to cell lines or tissues to quantify enzyme levels under various conditions.
Genetic manipulation in model organisms
Deletion of the yxkO gene in Bacillus subtilis was used to show that the dehydratase is required for stress adaptation. In mammalian cells, siRNA-mediated knockdown of NAXD increased NADHX levels and blocked adipocyte differentiation, providing a direct link to cell fate.
Structural and biochemical characterization
Structural studies of the enzyme, often combined with mutagenesis, have elucidated the catalytic mechanism and substrate specificity. Such work can guide the design of inhibitors or probes for further functional studies.
How CRISPR Can Be Used to Study GO:0047453 ATP-dependent NAD(P)H-hydrate dehydratase activity
Knockout
CRISPR knockout of NAXD or its homologs can be used to eliminate ATP-dependent NAD(P)H-hydrate dehydratase activity, enabling studies of NADHX accumulation and its effects on metabolism and differentiation. Such models are valuable for validating loss-of-function phenotypes observed with siRNA.
Point Mutation
Introducing point mutations in catalytic residues of NAXD can dissect the enzymatic mechanism and separate dehydratase activity from potential non-enzymatic functions. These models help confirm the importance of specific amino acids for ATP binding or catalysis.
Knock-in
Knock-in of epitope tags or fluorescent proteins at the endogenous NAXD locus allows real-time tracking of enzyme localization and interactions without overexpression artifacts. This approach can reveal whether the enzyme shuttles between cytoplasm and mitochondria under stress.
Overexpression
Overexpression of NAXD or bacterial homologs can test whether increased dehydratase activity protects cells from NADHX toxicity or enhances stress resistance. Such models are useful for gain-of-function studies and for producing recombinant enzyme for biochemical assays.
How EDITGENE Supports ATP-dependent NAD(P)H-hydrate dehydratase activity Research
Researchers studying ATP-dependent NAD(P)H-hydrate dehydratase activity-related genes often need to determine whether a candidate gene is causally involved in metabolic repair, stress responses or differentiation. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this functional validation.
Contact EDITGENE today to design your custom CRISPR model for ATP-dependent NAD(P)H-hydrate dehydratase activity research.
Frequently Asked Questions About ATP-dependent NAD(P)H-hydrate dehydratase activity
What is ATP-dependent NAD(P)H-hydrate dehydratase activity?
It is an enzyme activity defined by GO:0047453 that uses ATP to convert hydrated NAD(P)H back to normal NAD(P)H, releasing ADP, phosphate and H+.
What genes are involved in ATP-dependent NAD(P)H-hydrate dehydratase activity?
Key genes include NAXD (CARKD) in humans and yxkO in Bacillus subtilis, as well as related repair genes like NAXE and nudF.
What is the reaction catalyzed by GO:0047453?
The reaction is (6S)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide adenine dinucleotide + ATP = ADP + H+ + NAD(P)H + phosphate.
Why is NAD(P)H-hydrate dehydratase important for cells?
It prevents the accumulation of toxic hydrated NAD(P)H forms that can inhibit dehydrogenases and disrupt metabolism.
How is ATP-dependent NAD(P)H-hydrate dehydratase studied?
Common methods include metabolite screening, enzymology, siRNA knockdown, bacterial deletion mutants and proteomics.
What happens when NAXD is knocked down?
In 3T3-L1 cells, NAXD knockdown increases NADHX levels and inhibits adipocyte differentiation.
Is ATP-dependent NAD(P)H-hydrate dehydratase linked to human disease?
It has been detected in keratoconus tear proteomes, but direct disease mechanisms remain to be established.
What is the role of ATP in this enzyme activity?
ATP provides the energy for dehydration by donating a phosphoryl group, yielding ADP and phosphate.
Can CRISPR be used to study GO:0047453?
Yes, CRISPR knockout, point mutation, knock-in and overexpression models are powerful tools to dissect the function of this enzyme.
Where is ATP-dependent NAD(P)H-hydrate dehydratase located in the cell?
It is found in the cytoplasm and mitochondria of eukaryotic cells and in the cytosol of bacteria.
Conclusion
ATP-dependent NAD(P)H-hydrate dehydratase activity (GO:0047453) is a conserved metabolic repair function that safeguards NAD(P)H pools by removing inhibitory hydrated adducts. Its roles in bacterial stress adaptation and mammalian adipocyte differentiation highlight its physiological importance. The enzyme was functionally assigned through metabolite screening, demonstrating the power of integrative approaches. Although links to human disease are emerging, such as in keratoconus, further research is needed to fully understand its clinical relevance. CRISPR-based models will be instrumental in advancing this field.
References
- 1. Nakajima K et al.. 2025. Suppression of ATP-dependent (S)-NAD(P)H-hydrate dehydratase expression inhibits adipocyte differentiation of 3T3-L1 preadipocytes by increasing excessive accumulation of NADHX.. J Biochem 177(6):403-414 PMID: 40113573
- 2. Petrovova M et al.. 2014. NAD(P)H-hydrate dehydratase- a metabolic repair enzyme and its role in Bacillus subtilis stress adaptation.. PLoS One 9(11):e112590 PMID: 25393291
- 3. Shumilin IA et al.. 2012. Identification of unknown protein function using metabolite cocktail screening.. Structure 20(10):1715-25 PMID: 22940582
- 4. Yenihayat F et al.. 2018. Comparative proteome analysis of the tear samples in patients with low-grade keratoconus.. Int Ophthalmol 38(5):1895-1905 PMID: 28785876
