GO:0050135 NADP+ nucleosidase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0050135 (NADP+ nucleosidase activity) catalyzes the hydrolysis of NADP+ to ADP-D-ribose 2'-phosphate, nicotinamide and H+, a reaction that cleaves the nicotinamide-ribose bond of the dinucleotide.
• This activity belongs to the broader family of NAD(P)+ glycohydrolases / NADases, enzymes that consume NAD+ and NADP+ and thereby control cellular redox and signaling pools.
• The best-characterized mammalian enzyme with this activity is CD38, a multifunctional ectoenzyme whose NADase activity declines with age and contributes to age-related NAD decline and mitochondrial dysfunction.
• Plant and animal TIR-domain proteins, SARM1, DSR2 and short prokaryotic Argonaute proteins display related NAD(P)+ cleavage activities that are central to immune signaling and cell death.
• Sir2-HerA anti-phage defense systems combine NAD+ cleavage with other enzymatic activities, illustrating how NAD(P)+ nucleosidase chemistry is repurposed in bacterial immunity.
• NADP+ nucleosidase activity can be studied with biochemical assays, structural biology, CRISPR knockout/knock-in models and CRISPR library screening to link genotype to NAD(P)+ metabolism and disease phenotypes.
Description
NADP+ nucleosidase activity (GO:0050135) is a molecular function defined by the hydrolysis of NADP+ into ADP-D-ribose 2'-phosphate, nicotinamide and a proton. This reaction belongs to the larger family of NAD(P)+ glycohydrolase activities that regulate the cellular pools of pyridine dinucleotides, which are central to redox metabolism, calcium signaling and post-translational ADP-ribosylation. Because NADP+ is a key electron carrier in anabolic reactions and a precursor of NADPH, its cleavage by nucleosidases can directly influence antioxidant defense and biosynthetic pathways. The physiological importance of NADP+ nucleosidase activity is best illustrated by CD38, a mammalian ectoenzyme that hydrolyzes NAD+ and NADP+ and whose expression increases with age, contributing to the age-related decline in NAD+ levels and to mitochondrial dysfunction through a SIRT3-dependent mechanism. Related NAD(P)+ cleavage activities are found in plant and animal TIR-domain immune receptors, in the neuronal protein SARM1, in bacterial anti-phage defense systems such as DSR2 and Sir2-HerA, and in short prokaryotic Argonaute proteins, where NAD(P)+ hydrolysis triggers cell death or growth arrest. These examples show that NADP+ nucleosidase chemistry is not a metabolic curiosity but a recurrent signaling module in immunity, neurodegeneration and aging. For researchers, GO:0050135 provides a precise annotation target for genes and proteins that cleave NADP+. Understanding which enzymes carry this activity, how they are regulated and what phenotypes result from their loss or gain of function is essential for dissecting NAD(P)+ biology and for developing therapeutic strategies that modulate NAD+ and NADP+ levels in cancer, neurodegeneration and infectious disease.
NADP+ nucleosidase activity At A Glance
| GO ID | GO:0050135 |
|---|---|
| GO term | NADP+ nucleosidase activity |
| Ontology | molecular_function |
| Synonym | NADPase activity; NADP+ glycohydrolase activity; NAD(P)+ nucleosidase activity; NADP nucleosidase activity; NADP(+) nucleosidase activity |
| Major function | Hydrolysis of NADP+ to ADP-D-ribose 2'-phosphate, nicotinamide and H+ |
| Reaction | NADP+ + H2O = ADP-D-ribose 2'-phosphate + nicotinamide + H+ |
| Substrate | NADP+ (and in some enzymes NAD+) |
| Products | ADP-D-ribose 2'-phosphate, nicotinamide, H+ |
| Representative enzymes | CD38, TIR-domain proteins, SARM1, DSR2, Sir2-HerA systems, short prokaryotic Argonaute |
| Related activity | NAD+ nucleosidase / NADase activity (GO:0003953) |
What Is GO:0050135?
NADP+ nucleosidase activity (GO:0050135) is the catalysis of the reaction NADP+ + H2O = ADP-D-ribose 2'-phosphate + nicotinamide + H+. In other words, the enzyme breaks the bond between the nicotinamide moiety and the ribose-phosphate portion of NADP+, releasing free nicotinamide and ADP-D-ribose 2'-phosphate. This is a hydrolytic (glycohydrolase) reaction that consumes water and produces a proton. The term is synonymous with NADPase activity, NADP+ glycohydrolase activity, NAD(P)+ nucleosidase activity, NADP nucleosidase activity and NADP(+) nucleosidase activity, reflecting the fact that many enzymes annotated with this function can also act on NAD+.
Why Is NADP+ nucleosidase activity Important in Cell Biology?
NADP+ nucleosidase activity matters because it directly controls the availability of NADP+, a central electron carrier and the precursor of NADPH, and because the same enzymes often cleave NAD+, thereby influencing NAD+-dependent signaling, DNA repair, calcium mobilization and immune cell death. Dysregulated NAD(P)+ hydrolysis has been linked to age-related metabolic decline, neurodegeneration and cancer, and bacterial anti-phage defense systems exploit this chemistry to abort infection. Consequently, measuring and manipulating GO:0050135 is relevant to aging research, immunology, neurobiology and antimicrobial development.
• Controls NADP+ and NADPH pools, affecting antioxidant defense and reductive biosynthesis.
• Regulates NAD+ availability, which is required for sirtuin and PARP activities.
• CD38-mediated NAD decline contributes to age-related mitochondrial dysfunction through SIRT3.
• TIR-domain NAD(P)+ cleavage is a conserved immune signaling mechanism in plants and animals.
• SARM1 NADase activity is a central executioner of axon degeneration and a drug target.
• Bacterial DSR2 and Sir2-HerA systems use NAD(P)+ hydrolysis for anti-phage defense.
• Short prokaryotic Argonaute proteins are activated by nucleic acids to cleave NAD(P)+ and abort infection.
• NADP+ nucleosidase activity is a candidate biomarker and therapeutic node in cancer and neurodegeneration.
• Enzymes with this activity are attractive targets for small-molecule inhibitors.
• CRISPR models of these enzymes enable causal testing of NAD(P)+ metabolism in disease.
What Happens During NADP+ nucleosidase activity?
Substrate binding and recognition of NADP+
In simple terms: The enzyme first grabs the NADP+ molecule and positions it so that the bond to be cut is exposed.
NADP+ nucleosidases bind NADP+ in a pocket that recognizes the adenine, ribose and phosphate moieties of the dinucleotide. Structural studies of related NAD(P)+-cleaving enzymes such as SARM1 and DSR2 show that substrate recognition involves conserved residues that coordinate the nicotinamide-ribose bond and the 2'-phosphate group that distinguishes NADP+ from NAD+. In CD38, the active site accommodates both NAD+ and NADP+, explaining the synonym NAD(P)+ nucleosidase activity.
Hydrolysis of the nicotinamide-ribose bond
In simple terms: Water is used to split the molecule, releasing nicotinamide and leaving the rest of the molecule behind.
The catalytic step is a hydrolysis reaction in which a water molecule attacks the nicotinamide-ribose bond, producing free nicotinamide and ADP-D-ribose 2'-phosphate. This is the defining chemistry of GO:0050135 and is shared with NAD+ nucleosidases, which release ADP-ribose instead. The reaction also releases a proton, which can locally acidify the active site and influence enzyme turnover.
Product release and downstream signaling
In simple terms: After the cut, the products are released and can act as signals or be recycled.
The products of NADP+ hydrolysis, nicotinamide and ADP-D-ribose 2'-phosphate, are released from the active site. Nicotinamide can be recycled into NAD+ through the salvage pathway, while ADP-ribose derivatives can act as calcium-mobilizing second messengers in some systems. In immune signaling, the cleavage of NAD(P)+ by TIR-domain enzymes generates signaling molecules that trigger cell death.
Coupling to cell death and immune defense
In simple terms: In some proteins, cutting NAD(P)+ is a signal that tells the cell to self-destruct or stop an infection.
In plant and animal TIR-domain proteins, NAD(P)+ cleavage is coupled to the production of 2',3'-cAMP/cGMP and to activation of cell death pathways. SARM1 uses NADase activity to execute axon degeneration, and small-molecule inhibitors of this activity protect neurons. Bacterial DSR2 and Sir2-HerA systems use NAD(P)+ hydrolysis to abort phage infection, and short prokaryotic Argonaute proteins are activated by nucleic acids to cleave NAD(P)+ and trigger growth arrest.
Key Genes Involved in GO:0050135 NADP+ nucleosidase activity
The following genes and proteins are experimentally linked to NADP+ nucleosidase activity or to closely related NAD(P)+ cleavage functions.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CD38 | Mammalian ectoenzyme with NAD(P)+ nucleosidase activity | Age-related NAD decline, mitochondrial dysfunction, SIRT3-dependent mechanism |
| SARM1 | Neuronal NADase with NAD(P)+ cleavage activity | Axon degeneration, inhibitor development, structural basis of activation |
| TIR domain proteins (plant) | NAD(P)+ cleavage and 2',3'-cAMP/cGMP synthesis | Plant immunity and cell death signaling |
| TIR domain proteins (animal) | NAD+ cleavage in cell death pathways | Innate immune signaling and neurodegeneration |
| DSR2 | Bacterial NADase in anti-phage defense | Phage protein inhibition, structural basis of activation |
| Sir2-HerA system | Multi-enzymatic anti-phage defense with NAD+ cleavage | Bacterial immunity and allosteric activation |
| Short prokaryotic Argonaute | Nucleic-acid-triggered NADase | Prokaryotic immunity and abortive infection |
| NAD(P)+ glycohydrolases (general) | Hydrolysis of NAD+ and NADP+ | Redox and signaling regulation |
| SIRT3 | Mitochondrial deacetylase downstream of NAD decline | Mediates mitochondrial dysfunction in CD38-high states |
| PARPs | NAD+-consuming enzymes | Competition for NAD+ with NAD(P)+ nucleosidases |
| Nicotinamide salvage enzymes | Recycle nicotinamide to NAD+ | Counterbalance NAD(P)+ hydrolysis |
| Calcium signaling channels | Respond to ADP-ribose derivatives | Downstream of NAD(P)+ cleavage |
| Immune receptor complexes | Contain TIR-domain NAD(P)+ cleaving enzymes | Cell death and immunity |
| Phage defense operons | Encode DSR2 and Sir2-HerA | Anti-phage defense mechanisms |
| Argonaute defense loci | Encode short pAgo | Nucleic-acid-triggered NAD(P)+ cleavage |
| Axon degeneration pathway genes | Downstream of SARM1 NADase | Neurodegeneration models |
How Is NADP+ nucleosidase activity Regulated?
NADP+ nucleosidase activity is regulated at multiple levels. CD38 expression increases with age and inflammatory signals, leading to lower NAD+ levels and mitochondrial dysfunction through SIRT3. SARM1 is kept inactive by autoinhibition until injury or metabolic stress triggers its NADase activity, and small molecules can lock it in the inactive state. DSR2 and Sir2-HerA systems are allosterically activated by phage proteins or nucleic acids, ensuring that NAD(P)+ cleavage occurs only during infection. Short prokaryotic Argonaute proteins are activated by guide RNA or DNA to cleave NAD(P)+, coupling nucleic-acid recognition to abortive infection. These examples show that NADP+ nucleosidase activity is tightly controlled by conformational changes, allosteric activators and expression levels.
NADP+ nucleosidase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CD38 | Age-related NAD decline and mitochondrial dysfunction | CD38 knockout and overexpression cell lines, SIRT3 readouts |
| SARM1 | Axon degeneration and neuropathy | SARM1 point-mutation and knockout neurons, inhibitor testing |
| TIR domain proteins | Plant and animal immune cell death | TIR-domain knockout and knock-in models, cell death assays |
| DSR2 | Bacterial anti-phage defense | DSR2 knockout and phage challenge assays |
| Short pAgo | Prokaryotic immunity | pAgo knockout and nucleic-acid-triggered NADase assays |
Aging and metabolic decline
CD38-mediated NAD(P)+ hydrolysis increases with age and contributes to the decline in NAD+ levels, mitochondrial dysfunction and metabolic dysregulation through a SIRT3-dependent mechanism. This makes NADP+ nucleosidase activity a candidate target for interventions aimed at preserving NAD+ pools during aging.
Neurodegeneration
SARM1 is a neuronal NAD(P)+-cleaving enzyme whose activation triggers axon degeneration, a hallmark of peripheral neuropathies and neurodegenerative diseases. Structural and pharmacological studies have identified small-molecule inhibitors that block SARM1 NADase activity, providing a potential therapeutic strategy.
Infection and immunity
TIR-domain proteins in plants and animals use NAD(P)+ cleavage to trigger cell death and immune signaling, while bacterial DSR2, Sir2-HerA and short Argonaute systems use NAD(P)+ hydrolysis for anti-phage defense. Understanding these mechanisms may inform new antimicrobial or immunomodulatory approaches.
From NADP+ nucleosidase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of CD38 raise NAD+ and improve mitochondrial function? | CD38 knockout cell lines and SIRT3 activity assays |
| Does SARM1 NADase activity cause axon degeneration? | SARM1 knockout and point-mutation neurons |
| How do TIR domains trigger cell death? | TIR-domain knockout and knock-in cell lines with cell death readouts |
| How is DSR2 activated by phage proteins? | DSR2 knockout bacteria and phage infection assays |
| What is the role of Sir2-HerA in anti-phage defense? | Sir2-HerA knockout and allosteric activation assays |
| How does short pAgo cleave NAD(P)+? | pAgo knockout and nucleic-acid-triggered NADase assays |
How to Study the NADP+ nucleosidase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| HPLC / mass spectrometry | NADP+ consumption and product formation | Enzyme kinetics of CD38, SARM1, TIR proteins |
| Fluorometric NADase assay | NAD(P)+ cleavage rate | High-throughput inhibitor screening |
| Cryo-EM / X-ray crystallography | Active-site structure and conformational changes | Mechanistic studies of SARM1, DSR2, Sir2-HerA |
| CRISPR knockout | Loss-of-function phenotypes | Testing causal roles in aging and immunity |
| CRISPR knock-in | Point-mutation effects on activity | Dissecting catalytic residues |
| CRISPR library screening | Genome-wide modifiers of NAD(P)+ phenotypes | Discovery of new pathway components |
| Transcriptomics / proteomics | Expression changes in NAD(P)+ metabolism | Pathway analysis in disease models |
| Cell death assays | Viability and apoptosis readouts | TIR-domain and SARM1 signaling |
Biochemical NAD(P)+ nucleosidase assays
Enzymatic activity of NADP+ nucleosidases can be measured by monitoring the conversion of NADP+ to ADP-D-ribose 2'-phosphate and nicotinamide using HPLC, mass spectrometry or fluorometric assays. These methods are used to characterize CD38, SARM1, TIR-domain proteins and bacterial defense enzymes.
Structural biology
Cryo-EM and X-ray crystallography have revealed the active-site architecture and activation mechanisms of SARM1, DSR2 and Sir2-HerA systems, providing templates for inhibitor design.
CRISPR knockout and knock-in models
CRISPR-Cas9 knockout of CD38, SARM1 or bacterial defense genes, combined with knock-in of point mutations, allows causal testing of NADP+ nucleosidase activity in aging, neurodegeneration and immunity.
CRISPR library screening and bioinformatics
Genome-wide CRISPR screens can identify genes that modify NAD(P)+ levels or cell death phenotypes, and bioinformatics pipelines can prioritize NAD(P)+ nucleosidase candidates for functional validation.
How CRISPR Can Be Used to Study GO:0050135 NADP+ nucleosidase activity
Knockout
CRISPR knockout of CD38, SARM1 or bacterial defense genes eliminates NADP+ nucleosidase activity and allows researchers to measure the consequences for NAD+ levels, mitochondrial function and cell survival.
Point Mutation
Point mutations in catalytic residues of SARM1, TIR domains or short pAgo can abolish NAD(P)+ cleavage while preserving protein folding, providing clean tests of enzymatic function.
Knock-in
Knock-in of disease-associated or activating mutations can model gain-of-function NAD(P)+ hydrolysis and its downstream effects on immunity and neurodegeneration.
Overexpression
Overexpression of CD38 or SARM1 in cell lines increases NAD(P)+ hydrolysis and lowers NAD+ levels, mimicking age-related or injury-induced states for drug testing.
How EDITGENE Supports NADP+ nucleosidase activity Research
Researchers studying NADP+ nucleosidase activity-related genes often need to determine whether a candidate gene is causally involved in NAD(P)+ metabolism, cell death or immune defense. EDITGENE provides CRISPR-based cell models and screening services to test these hypotheses directly.
Contact EDITGENE today to design your custom CRISPR model for NADP+ nucleosidase activity research.
Frequently Asked Questions About NADP+ nucleosidase activity
What is NADP+ nucleosidase activity?
NADP+ nucleosidase activity (GO:0050135) is the hydrolysis of NADP+ to ADP-D-ribose 2'-phosphate, nicotinamide and H+, a reaction that cleaves the nicotinamide-ribose bond of the dinucleotide.
What genes are involved in NADP+ nucleosidase activity?
Genes include CD38, SARM1, plant and animal TIR-domain proteins, DSR2, Sir2-HerA systems and short prokaryotic Argonaute proteins.
What is the reaction catalyzed by GO:0050135?
The reaction is NADP+ + H2O = ADP-D-ribose 2'-phosphate + nicotinamide + H+.
How is NADP+ nucleosidase activity different from NAD+ nucleosidase activity?
Both cleave the nicotinamide-ribose bond, but NADP+ nucleosidases act on NADP+ and release ADP-D-ribose 2'-phosphate, while NAD+ nucleosidases release ADP-ribose; many enzymes can act on both substrates.
Why is CD38 important for NADP+ nucleosidase activity?
CD38 is a mammalian ectoenzyme with NAD(P)+ nucleosidase activity whose age-related increase contributes to NAD decline and mitochondrial dysfunction through SIRT3.
How does SARM1 relate to NADP+ nucleosidase activity?
SARM1 is a neuronal NAD(P)+-cleaving enzyme whose activation triggers axon degeneration and is a target for small-molecule inhibitors.
What role does NADP+ nucleosidase activity play in immunity?
TIR-domain proteins, DSR2, Sir2-HerA and short pAgo use NAD(P)+ cleavage to trigger cell death or abort phage infection.
How can I study NADP+ nucleosidase activity in the lab?
Common methods include biochemical NAD(P)+ cleavage assays, structural biology, CRISPR knockout/knock-in models and CRISPR library screening.
What diseases are linked to NADP+ nucleosidase activity?
Age-related metabolic decline, neurodegeneration and infectious disease processes have been linked to NAD(P)+ hydrolysis.
Can CRISPR be used to model NADP+ nucleosidase activity?
Yes, CRISPR knockout, point mutation, knock-in and overexpression models allow causal testing of NAD(P)+ cleaving enzymes in disease and immunity.
Conclusion
NADP+ nucleosidase activity (GO:0050135) is a conserved enzymatic function that cleaves NADP+ and, in many enzymes, NAD+, thereby controlling redox and signaling pools central to aging, immunity and neurodegeneration. From CD38 and SARM1 in mammals to TIR-domain proteins and bacterial defense systems, this activity is repeatedly used as a switch for cell death and metabolic adaptation. CRISPR-based models and biochemical assays provide the tools needed to dissect its mechanisms and therapeutic potential.
References
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- 2. Yu D et al.. 2022. TIR domains of plant immune receptors are 2',3'-cAMP/cGMP synthetases mediating cell death.. Cell 185(13):2370-2386.e18 PMID: 35597242
- 3. Shi Y et al.. 2022. Structural basis of SARM1 activation, substrate recognition, and inhibition by small molecules.. Mol Cell 82(9):1643-1659.e10 PMID: 35334231
- 4. Wang R et al.. 2024. The structural basis of the activation and inhibition of DSR2 NADase by phage proteins.. Nat Commun 15(1):6185 PMID: 39039073
- 5. Tang D et al.. 2023. Multiple enzymatic activities of a Sir2-HerA system cooperate for anti-phage defense.. Mol Cell 83(24):4600-4613.e6 PMID: 38096825
- 6. Horsefield S et al.. 2019. NAD(+) cleavage activity by animal and plant TIR domains in cell death pathways.. Science 365(6455):793-799 PMID: 31439792
- 7. Zhen X et al.. 2024. Mechanistic basis for the allosteric activation of NADase activity in the Sir2-HerA antiphage defense system.. Nat Commun 15(1):9269 PMID: 39465277
- 8. Gao X et al.. 2024. Nucleic-acid-triggered NADase activation of a short prokaryotic Argonaute.. Nature 625(7996):822-831 PMID: 37783228
