GO:0070403 NAD+ binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070403 (NAD+ binding) describes the molecular function of selectively binding the oxidized form of nicotinamide adenine dinucleotide (NAD+), a central redox and signaling coenzyme.
• NAD+ binding is mediated by structurally diverse modules, including Rossmann-fold domains and macrodomains, and can be detected by sequence motifs and biophysical assays.
• NAD+ binding controls protein function beyond metabolism, as shown for the oncogenic transcription factors CtBP1 and CtBP2, where NAD(H) binding is linked to tetrameric assembly.
• NAD+-sensing RNAs (riboswitches) also bind NAD+ with high specificity, revealing distinct ligand-binding pockets and conformational changes.
• Bacterial regulators such as NadR use NAD-dependent DNA binding to control gene expression, linking NAD+ availability to transcription.
• NAD+ binding is a tractable target for CRISPR-based knockout, point-mutation, knock-in, and overexpression models to dissect its role in disease and drug discovery.
Description
NAD+ binding (GO:0070403) is a molecular function defined as the selective interaction with the oxidized form of nicotinamide adenine dinucleotide (NAD+), a coenzyme involved in many redox and biosynthetic reactions. This function is distinct from binding to the reduced form NADH, although some proteins can accommodate both. NAD+ binding underlies fundamental processes such as electron transfer, ADP-ribosylation, and transcriptional regulation, making it a central node in cellular metabolism and signaling. Researchers study NAD+ binding to understand how cells sense energy status, how pathogens regulate virulence, and how dysregulation contributes to cancer and metabolic disease. The availability of high-resolution structures and biophysical assays has accelerated the discovery of NAD+-binding proteins and their ligands. In this article, we integrate authoritative QuickGO annotation with real PubMed literature to provide a research-grade overview of GO:0070403, its mechanisms, key genes, disease links, and experimental models.
NAD+ binding At A Glance
| GO ID | GO:0070403 |
|---|---|
| GO term | NAD+ binding |
| Ontology | molecular_function |
| Synonym | NAD binding; NAD (oxidized) binding; oxidized NAD binding; oxidized nicotinamide adenine dinucleotide binding |
| Definition | Binding to the oxidized form, NAD, of nicotinamide adenine dinucleotide, a coenzyme involved in many redox and biosynthetic reactions. |
| Major function | Selective recognition and interaction with NAD+ to facilitate redox reactions, ADP-ribosylation, and regulatory signaling. |
| Related cofactors | NAD+, NADH, NADP+, and their metabolites; some proteins discriminate between oxidized and reduced forms. |
| Structural motifs | Rossmann-fold, macrodomain, and riboswitch aptamer domains are common NAD+-binding modules. |
| Detection methods | Sequence motif analysis, FRET, biolayer interferometry, and X-ray crystallography. |
What Is GO:0070403?
GO:0070403 (NAD+ binding) is the molecular function of binding to the oxidized form of nicotinamide adenine dinucleotide (NAD+), a coenzyme that participates in numerous redox and biosynthetic reactions. This term specifically refers to non-covalent or covalent interaction with NAD+ (oxidized), excluding binding to NADH or other dinucleotides unless explicitly noted. It is a child of the broader 'nucleotide binding' and 'coenzyme binding' terms in the Gene Ontology.
Why Is NAD+ binding Important in Cell Biology?
NAD+ binding is essential for cellular energy metabolism, redox homeostasis, and signaling, and its dysregulation is implicated in cancer, infectious disease, and metabolic disorders. Understanding this function at molecular resolution enables the design of inhibitors and probes that target NAD+-dependent enzymes and regulatory proteins.
• NAD+ binding is required for the catalytic activity of dehydrogenases and other redox enzymes.
• It regulates transcription factors such as CtBP1/2, linking metabolic state to gene expression.
• NAD+-binding macrodomains are involved in viral pathogenesis and host immune evasion.
• Bacterial NAD+-dependent regulators like NadR control virulence gene expression.
• NAD+ riboswitches sense cellular NAD+ levels to control gene expression in bacteria.
• NAD+ binding is a target for antibacterial drug discovery due to unique motifs in pathogens.
• Dysregulated NAD+ binding contributes to cancer progression and metabolic reprogramming.
• NAD+ binding assays are used in high-throughput screening for enzyme inhibitors.
• It is critical for ADP-ribosylation reactions in DNA repair and cell death pathways.
• NAD+ binding modulates protein-protein interactions and complex assembly.
Mechanism, Genes and Research Methods
What Happens During NAD+ binding?
In simple terms: NAD+ binding is the first step in many cellular processes where the coenzyme docks into a protein pocket.
NAD+ binding typically begins with the recognition of the oxidized dinucleotide by a specific binding pocket. For example, the oncogenic transcription factors CtBP1 and CtBP2 bind NAD(H) with distinct affinities, and this binding is coupled to their tetrameric assembly. In bacterial NadR, NAD+ binding modulates DNA-binding activity, allowing the regulator to sense NAD+ levels and control gene expression. Riboswitches, such as the NAD+-II riboswitch, undergo conformational changes upon NAD+ binding, which can regulate downstream gene expression. These events highlight that NAD+ binding is not merely a passive interaction but a trigger for functional transitions.
Structural Basis of NAD+ Recognition
In simple terms: Proteins use specific folds to grab NAD+ in a way that distinguishes it from similar molecules.
The Rossmann fold is a classic NAD+-binding domain found in many dehydrogenases, and sequence motifs can predict NAD(P)-binding proteins. Macrodomains, such as the MERS-CoV macro domain, bind NAD+ metabolites with tunable affinity, as shown by biophysical and structural studies. The NAD+-II riboswitch adopts two distinct ligand-binding pockets, enabling specific recognition of NAD+ over other nucleotides. These structural insights are critical for designing selective inhibitors.
Cofactor Specificity and Discrimination
In simple terms: Some proteins can tell the difference between NAD+ and its reduced form NADH, while others cannot.
CtBP1 and CtBP2 exhibit different binding affinities for NAD+ versus NADH, and this discrimination affects their oligomeric state and transcriptional activity. The MERS-CoV macro domain can bind various NAD+ metabolites, but with different affinities, suggesting tunable specificity. Such discrimination is essential for proper cellular responses to redox changes.
Regulation of NAD+ Binding
In simple terms: Cells control when and where NAD+ binding happens by adjusting cofactor levels and protein modifications.
The NAMPT enzyme employs a switch that senses AMP/ATP and regulates cellular responses to energy stress, indirectly affecting NAD+ availability for binding. NAD+ levels are also influenced by biosynthetic and salvage pathways, which can alter the occupancy of NAD+-binding proteins. Post-translational modifications and protein-protein interactions can further modulate binding affinity.
Functional Consequences of NAD+ Binding
In simple terms: Once NAD+ binds, it can change a protein's shape, activity, or interactions with other molecules.
In CtBP1/2, NAD(H) binding promotes tetramerization, which is linked to their oncogenic functions. In bacterial NadR, NAD+ binding inhibits DNA binding, thereby regulating gene expression. In the context of ADP-ribosylation, NAD+ binding to enzymes like those in the OspC3 pathway is required for modifying target proteins and blocking pyroptosis. These examples illustrate the diverse functional outcomes of NAD+ binding.
Key Genes Involved in GO:0070403 NAD+ binding
The following genes encode proteins that directly bind NAD+ or regulate its availability, as supported by the cited literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CtBP1 | Transcriptional corepressor; binds NAD(H) and assembles into tetramers | Oncogenic roles in cancer; model for NAD+-dependent assembly |
| CtBP2 | Transcriptional corepressor; NAD(H) binding linked to tetramerization | Cancer and developmental studies |
| NAMPT | Rate-limiting enzyme in NAD+ salvage; senses AMP/ATP | Metabolic stress responses; drug target |
| NadR | Bifunctional regulator with NAD-dependent DNA-binding activity | Bacterial gene regulation; antibacterial target |
| OspC3 | Shigella effector that uses NAD+ for ADP-riboxanation | Host-pathogen interactions; pyroptosis |
| Macrodomain (MERS-CoV) | Binds NAD+ metabolites with tunable affinity | Viral pathogenesis; antiviral development |
| NAD+-II riboswitch | RNA element that binds NAD+ and regulates gene expression | RNA-targeting antibiotics |
| NAD+ riboswitch (other) | Binds NAD+ with high specificity | Synthetic biology; RNA sensors |
| GAPDH | Glycolytic enzyme with NAD+ binding site (inferred from motif) | Metabolic studies; drug discovery |
| LDH | Lactate dehydrogenase; NAD+ binding for catalysis (inferred) | Cancer metabolism |
| SIRT1 | NAD+-dependent deacetylase (inferred from NAD+ binding) | Aging and metabolism |
| PARP1 | NAD+-dependent ADP-ribosyltransferase (inferred) | DNA repair; cancer therapy |
| CD38 | NAD+ glycohydrolase (inferred) | Immune regulation; NAD+ homeostasis |
| NADSYN1 | NAD+ biosynthesis (inferred) | Metabolic disorders |
| NNMT | Nicotinamide N-methyltransferase; affects NAD+ levels (inferred) | Cancer and obesity |
| NADK | NAD kinase; converts NAD+ to NADP+ (inferred) | Redox regulation |
| ALDH | Aldehyde dehydrogenase; NAD+ binding for oxidation (inferred) | Cancer stem cells |
| IDH | Isocitrate dehydrogenase; NAD+ binding (inferred) | Oncometabolism |
How Is NAD+ binding Regulated?
NAD+ binding is regulated by the availability of NAD+, which is controlled by biosynthetic enzymes such as NAMPT that sense energy status via AMP/ATP. Additionally, protein-protein interactions and post-translational modifications can modulate the affinity of NAD+-binding proteins, as seen for CtBP1/2 and NadR.
NAD+ binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CtBP1 | Cancer (transcriptional corepression) | Knockout and point-mutation models in cancer cell lines |
| CtBP2 | Cancer and developmental disorders | Knock-in of NAD+-binding mutants |
| NAMPT | Metabolic disorders (energy stress) | Overexpression and knockout in metabolic cell models |
| NadR | Bacterial virulence (Salmonella) | Bacterial knockout and NAD+-binding point mutants |
| OspC3 | Host-pathogen interaction (Shigella) | Knock-in of catalytic mutants in host cells |
Cancer
CtBP1 and CtBP2 are oncogenic transcription factors whose NAD(H) binding and tetramerization are linked to cancer progression. Targeting NAD+ binding may disrupt their oncogenic functions.
Infectious Diseases
Bacterial pathogens like Salmonella use NadR to sense NAD+ and regulate virulence genes. Shigella effector OspC3 requires NAD+ binding to ADP-riboxanate caspase-4/11 and block pyroptosis, highlighting a role in host-pathogen interactions.
Metabolic Disorders
NAMPT, a key regulator of NAD+ levels, employs a switch that senses AMP/ATP and regulates cellular responses to energy stress, implicating NAD+ binding in metabolic diseases such as diabetes and obesity.
Viral Infections
The MERS-CoV macro domain binds NAD+ metabolites with tunable affinity, which may contribute to viral pathogenesis and immune evasion.
From NAD+ binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of NAD+ binding affect protein function? | Knockout of the NAD+-binding domain via CRISPR |
| How does a specific point mutation alter NAD+ affinity? | Point-mutation knock-in of binding-site residues |
| Can a tag reveal NAD+-binding dynamics? | Tagged knock-in with fluorescent or affinity tags |
| What is the effect of NAD+ binding on gene expression? | Overexpression of wild-type vs. binding-deficient mutants |
| Can we screen for inhibitors of NAD+ binding? | CRISPR library screening coupled with NAD+ binding assays |
| How does NAD+ binding regulate complex assembly? | Knock-in of oligomerization-disrupting mutations |
How to Study the NAD+ binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| FRET | Conformational changes upon NAD+ binding | Riboswitch dynamics |
| Biolayer interferometry | Binding affinity and kinetics | Ligand screening |
| X-ray crystallography | Atomic structure of NAD+ binding pocket | Structure-based drug design |
| Sequence motif analysis | Prediction of NAD(P)-binding proteins | Genome-wide discovery |
| CRISPR knockout | Loss-of-function phenotypes | Target validation |
| CRISPR point mutation | Effect of specific residues on NAD+ binding | Mechanistic studies |
| RNA-seq | Transcriptional changes upon NAD+ binding modulation | Pathway analysis |
| Proteomics | Protein interaction changes | Complex assembly studies |
Biophysical Binding Assays
FRET and biolayer interferometry can measure NAD+ binding affinity and kinetics in real time, as demonstrated for NAD+ riboswitches. These methods are suitable for high-throughput screening of ligands.
Structural Biology
X-ray crystallography and cryo-EM reveal the atomic details of NAD+ binding pockets, as shown for the NAD+-II riboswitch and macrodomains. These structures guide rational drug design.
Sequence Motif Analysis
Computational detection of NAD(P)-binding motifs can identify new NAD+-binding proteins and unique drug targets. This approach is scalable and complements experimental validation.
Functional Genomics
CRISPR knockout and point-mutation screens can systematically test the role of NAD+-binding residues in cellular phenotypes. Coupled with RNA-seq, they reveal downstream transcriptional changes.
How CRISPR Can Be Used to Study GO:0070403 NAD+ binding
Knockout
CRISPR knockout of genes encoding NAD+-binding proteins, such as CtBP1/2, can reveal their essential functions in cancer cell lines. Knockout models are valuable for validating drug targets.
Point Mutation
Introducing point mutations in NAD+-binding residues via CRISPR can dissect the contribution of NAD+ binding to protein function without eliminating the protein. This is critical for understanding specificity.
Knock-in
Knock-in of tagged or mutant versions of NAD+-binding proteins allows real-time tracking and functional analysis. For example, fluorescent tags can monitor NAD+ binding dynamics in live cells.
Overexpression
Overexpression of wild-type or NAD+-binding-deficient proteins can test gain-of-function effects and dominant-negative interactions. This approach is useful for studying transcriptional regulation.
How EDITGENE Supports NAD+ binding Research
Researchers studying NAD+ binding-related genes often need to determine whether a candidate gene is causally involved in a specific phenotype, and CRISPR-based models provide the most direct way to test this. EDITGENE offers a comprehensive suite of services to accelerate such studies.
Contact EDITGENE today to design your custom CRISPR model for NAD+ binding research.
Frequently Asked Questions About NAD+ binding
What is GO:0070403?
GO:0070403 is the Gene Ontology term for NAD+ binding, defined as binding to the oxidized form of nicotinamide adenine dinucleotide, a coenzyme involved in many redox and biosynthetic reactions.
What genes are involved in NAD+ binding?
Genes encoding NAD+-binding proteins include CtBP1, CtBP2, NAMPT, NadR, and OspC3, among others.
How is NAD+ binding studied?
Common methods include FRET, biolayer interferometry, X-ray crystallography, and sequence motif analysis.
Why is NAD+ binding important in cancer?
NAD+ binding regulates oncogenic transcription factors like CtBP1/2, and its dysregulation can promote cancer progression.
What is the difference between NAD+ binding and NADH binding?
NAD+ binding specifically refers to the oxidized form, while NADH binding refers to the reduced form; some proteins discriminate between them.
Can CRISPR be used to study NAD+ binding?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools to dissect NAD+ binding functions.
What are NAD+ riboswitches?
NAD+ riboswitches are RNA elements that bind NAD+ and regulate gene expression in bacteria.
How does NAD+ binding affect protein structure?
NAD+ binding can induce conformational changes and promote oligomerization, as seen in CtBP1/2 tetramerization.
What diseases are linked to NAD+ binding?
Diseases include cancer, metabolic disorders, and infections by pathogens like Salmonella and Shigella.
What services does EDITGENE offer for NAD+ binding research?
EDITGENE provides knockout, point mutation, knock-in, overexpression cell models, CRISPR library screening, and bioinformatics services.
Conclusion
NAD+ binding (GO:0070403) is a fundamental molecular function that impacts redox biology, transcription, and disease. By leveraging CRISPR models and biophysical assays, researchers can uncover new therapeutic targets. EDITGENE supports these efforts with tailored cell models and screening services.
References
- 1. Erlandsen H et al.. 2022. NADH/NAD(+) binding and linked tetrameric assembly of the oncogenic transcription factors CtBP1 and CtBP2.. FEBS Lett 596(4):479-490 PMID: 34997967
- 2. Conoan Nieves NE et al.. 2024. Ligand binding characteristics of an NAD(+) riboswitch revealed by FRET and biolayer interferometry.. Chem Commun (Camb) 61(2):346-349 PMID: 39635865
- 3. Peng X et al.. 2023. Crystal structures of the NAD+-II riboswitch reveal two distinct ligand-binding pockets.. Nucleic Acids Res 51(6):2904-2914 PMID: 36840714
- 4. Hua YH et al.. 2014. Sequence-motif detection of NAD(P)-binding proteins: discovery of a unique antibacterial drug target.. Sci Rep 4:6471 PMID: 25253464
- 5. Lin MH et al.. 2021. Elucidating the tunability of binding behavior for the MERS-CoV macro domain with NAD metabolites.. Commun Biol 4(1):123 PMID: 33504944
- 6. Penfound T et al.. 1999. NAD-dependent DNA-binding activity of the bifunctional NadR regulator of Salmonella typhimurium.. J Bacteriol 181(2):648-55 PMID: 9882682
- 7. Hou Y et al.. 2023. Structural mechanisms of calmodulin activation of Shigella effector OspC3 to ADP-riboxanate caspase-4/11 and block pyroptosis.. Nat Struct Mol Biol 30(3):261-272 PMID: 36624349
- 8. Zu Y et al.. 2025. The NAMPT enzyme employs a switch that directly senses AMP/ATP and regulates cellular responses to energy stress.. Mol Cell 85(12):2271-2286.e6 PMID: 40505662
