GO:0070463 tubulin-dependent ATPase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070463 (tubulin-dependent ATPase activity) is a molecular function defined as ATP hydrolysis that requires a tubulin dimer to accelerate release of ADP and phosphate.
• The activity is stimulated by microtubule-stabilizing and destabilizing agents such as taxol and vinblastine in porcine brain microtubule proteins.
• It is inhibited by the calcium-binding protein S100 and by protein-bound polysaccharide PS-K in microtubule preparations.
• Tubulin/aldose reductase association is linked to diabetic complications, and preventing this interaction delays pathology in rats.
• Gamma-tubulin-dependent assembly pathways are kinetically dominant for centrosomal aster formation in C. elegans.
• The term is distinct from general ATPase activity because it explicitly requires a tubulin dimer for catalytic turnover.
Description
GO:0070463, tubulin-dependent ATPase activity, is a molecular function ontology term describing the catalysis of ATP hydrolysis to ADP and phosphate where a tubulin dimer is required to accelerate product release. This activity is measured in microtubule protein preparations and is distinct from conventional ATPases because the tubulin dimer acts as an essential cofactor rather than a substrate. Understanding this term is important for researchers studying cytoskeletal dynamics, microtubule-associated proteins, and the pharmacological modulation of microtubule stability. The activity has been documented in porcine brain microtubule proteins and is sensitive to agents that alter microtubule polymerization, including taxol and vinblastine. It is also modulated by endogenous factors such as S100 protein and exogenous polysaccharides. In addition, tubulin-dependent processes contribute to centrosomal aster assembly through gamma-tubulin-dependent pathways. Because the term sits at the intersection of ATP metabolism and cytoskeletal regulation, it is relevant to cancer, neurodegeneration, and metabolic disease research.
tubulin-dependent ATPase activity At A Glance
| GO ID | GO:0070463 |
|---|---|
| GO term | tubulin-dependent ATPase activity |
| Ontology | molecular_function |
| Synonym | tubulin-activated ATPase activity |
| Major function | ATP hydrolysis to ADP and phosphate, accelerated by a tubulin dimer |
| Reaction | ATP + H2O = ADP + phosphate |
| Requirement | Presence of a tubulin dimer for accelerated ADP and phosphate release |
| Representative stimulators | Taxol and vinblastine in porcine brain microtubule proteins |
| Representative inhibitors | S100 protein and protein-bound polysaccharide PS-K |
What Is GO:0070463?
According to the QuickGO definition, tubulin-dependent ATPase activity is the catalysis of the reaction ATP + H2O = ADP + phosphate, where the presence of a tubulin dimer is required to accelerate the release of ADP and phosphate. In other words, the enzyme hydrolyzes ATP, but efficient turnover depends on a tubulin dimer being present to facilitate product release. This distinguishes it from ATPases that do not require tubulin for catalytic acceleration.
Why Is tubulin-dependent ATPase activity Important in Cell Biology?
Tubulin-dependent ATPase activity is important because it links ATP hydrolysis directly to microtubule biology, a system central to cell division, intracellular transport, and cytoskeletal organization. Pharmacological agents that stabilize or destabilize microtubules, such as taxol and vinblastine, stimulate this activity in brain microtubule preparations, indicating that the ATPase is sensitive to microtubule polymerization state. Endogenous regulators like S100 protein and polysaccharide PS-K can inhibit the activity, suggesting a role in calcium signaling and immune-related modulation of microtubule function. Moreover, tubulin interactions with aldose reductase are implicated in diabetic complications, and disrupting this association delays pathology in rats. Gamma-tubulin-dependent pathways are also critical for centrosomal aster assembly, connecting this activity to mitotic spindle formation. Therefore, the term is relevant to cancer, diabetes, and neurobiology research.
• Provides a mechanistic link between ATP hydrolysis and microtubule dynamics.
• Serves as a readout for microtubule-stabilizing and destabilizing drug effects.
• Is modulated by calcium-binding proteins such as S100, connecting to calcium signaling.
• Is influenced by immunomodulatory polysaccharides like PS-K.
• Tubulin/aldose reductase association is linked to diabetic complications.
• Gamma-tubulin-dependent assembly is kinetically dominant for centrosomal asters.
• Relevant to mitotic spindle assembly and cell division research.
• Potential target context for cancer therapeutics that alter microtubule stability.
• Relevant to neurodegeneration research through microtubule dysfunction.
• Useful for assay development in cytoskeletal pharmacology.
Core Biology of GO:0070463 tubulin-dependent ATPase activity
Biological Process: What Happens During tubulin-dependent ATPase activity?
In simple terms: ATP is split into ADP and phosphate, but this happens efficiently only when a tubulin dimer is present to help release the products.
The biological process associated with GO:0070463 is the hydrolysis of ATP to ADP and phosphate, where a tubulin dimer accelerates the release of ADP and phosphate. In porcine brain microtubule protein preparations, this activity is stimulated by taxol and vinblastine, indicating that microtubule polymerization state influences the reaction. The activity is also inhibited by S100 protein and by protein-bound polysaccharide PS-K, showing that endogenous and exogenous factors can modulate the process. This process is distinct from general ATPase activity because the tubulin dimer is required for efficient turnover.
Cellular Component: Structure and Composition of tubulin-dependent ATPase activity
In simple terms: The activity is found in microtubule protein complexes, where tubulin dimers provide the structural context needed for ATP hydrolysis.
Tubulin-dependent ATPase activity has been measured in microtubule protein preparations from porcine brain, which contain tubulin dimers and microtubule-associated proteins. The activity is associated with the microtubule cytoskeleton and is sensitive to agents that alter microtubule assembly, such as taxol and vinblastine. Gamma-tubulin-dependent pathways are also important for centrosomal aster assembly, linking this activity to microtubule-organizing centers. The presence of tubulin dimers is a defining structural requirement for the catalytic acceleration described in GO:0070463.
Molecular Function: Substrate and Catalytic Mechanism
In simple terms: The enzyme uses ATP as a substrate and needs a tubulin dimer to help release the products ADP and phosphate.
The molecular function is the catalysis of ATP + H2O = ADP + phosphate, with a tubulin dimer required to accelerate release of ADP and phosphate. This mechanism has been demonstrated in microtubule protein preparations where tubulin-dependent ATPase activity is stimulated by taxol and vinblastine. The activity is inhibited by S100 protein and PS-K, suggesting that accessory proteins and polysaccharides can interfere with the catalytic cycle. The tubulin dimer acts as a cofactor rather than a substrate, distinguishing this activity from classical ATPases.
Regulation by Microtubule-Targeting Agents
In simple terms: Drugs that change microtubule stability can increase this ATPase activity.
Taxol, a microtubule-stabilizing agent, stimulates tubulin-dependent ATPase activity in microtubule proteins from porcine brain. Vinblastine, a microtubule-destabilizing agent, also stimulates this activity in the same preparation. These findings indicate that the activity is regulated by the polymerization state of tubulin and can be used as a readout for microtubule-targeting drugs. The opposite effect is seen with S100 protein and PS-K, which inhibit the activity.
Regulation by Endogenous and Exogenous Factors
In simple terms: Proteins like S100 and polysaccharides like PS-K can turn down this ATPase activity.
S100 protein inhibits tubulin-dependent ATPase activity in microtubule proteins from porcine brain. Protein-bound polysaccharide PS-K also influences tubulin-dependent ATPase activity in microtubule protein preparations. These regulatory effects suggest that the activity can be modulated by calcium-binding proteins and immunomodulatory polysaccharides. Such regulation may have implications for cellular responses to stress and immune signals.
Key Genes Involved in GO:0070463 tubulin-dependent ATPase activity
The following genes and proteins are directly implicated in tubulin-dependent ATPase activity or its regulation based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| TUBB | Beta-tubulin, component of tubulin dimer required for ATPase acceleration | Core structural requirement for GO:0070463 |
| TUBA | Alpha-tubulin, component of tubulin dimer | Forms the tubulin dimer needed for activity |
| TUBG1 | Gamma-tubulin, involved in centrosomal aster assembly | Gamma-tubulin-dependent pathway for aster formation |
| TUBG2 | Gamma-tubulin family member | Potential role in microtubule nucleation |
| S100B | Calcium-binding protein that inhibits tubulin-dependent ATPase | Negative regulator of the activity |
| S100A1 | S100 family member | Potential modulator of microtubule function |
| AKR1B1 | Aldose reductase, interacts with tubulin | Tubulin/aldose reductase association in diabetic complications |
| MAPT | Microtubule-associated protein tau | Microtubule stabilization and ATPase regulation context |
| MAP1B | Microtubule-associated protein | Potential component of microtubule protein preparations |
| MAP2 | Microtubule-associated protein | Potential component of microtubule protein preparations |
| DYNC1H1 | Dynein heavy chain, microtubule motor | Microtubule-dependent transport context |
| KIF11 | Kinesin motor protein | Mitotic spindle function context |
| PLK1 | Polo-like kinase, mitotic regulator | Centrosomal assembly context |
| AURKA | Aurora kinase A, centrosome maturation | Gamma-tubulin-dependent aster assembly context |
| CDK1 | Cyclin-dependent kinase 1, mitotic regulator | Cell cycle context for microtubule dynamics |
| TP53 | Tumor suppressor, responds to microtubule poisons | Cancer research context |
| PS-K target | Protein-bound polysaccharide PS-K | Exogenous modulator of ATPase activity |
How Is tubulin-dependent ATPase activity Regulated?
Tubulin-dependent ATPase activity is regulated by microtubule-targeting agents such as taxol and vinblastine, which stimulate the activity in porcine brain microtubule proteins. It is inhibited by S100 protein, a calcium-binding protein, and by protein-bound polysaccharide PS-K. These findings indicate that the activity is sensitive to both pharmacological and endogenous modulators. In addition, gamma-tubulin-dependent pathways regulate centrosomal aster assembly, which is a related microtubule-dependent process.
tubulin-dependent ATPase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| AKR1B1 | Diabetic complications via tubulin/aldose reductase association | Knockout or point-mutation in diabetic rat models |
| TUBB | Microtubule dysfunction in cancer and neurodegeneration | Knockout or point-mutation in cancer cell lines |
| TUBG1 | Centrosomal assembly defects | Knockout in C. elegans or human cells |
| S100B | Calcium signaling and neurodegeneration | Overexpression or knockout in neuronal cells |
| MAPT | Tauopathy and microtubule instability | Knock-in of disease mutations in tau |
Diabetes and Metabolic Complications
Tubulin/aldose reductase association is linked to the development of pathological complications in diabetic rats, and preventing this interaction delays pathology. This suggests that tubulin-dependent processes, including ATPase activity, may contribute to diabetic complications. Aldose reductase (AKR1B1) interacts with tubulin, and this interaction is a potential therapeutic target.
Cancer and Microtubule-Targeting Therapy
Microtubule-targeting agents such as taxol and vinblastine stimulate tubulin-dependent ATPase activity in brain microtubule preparations. Because these agents are used in cancer therapy, the activity may serve as a pharmacodynamic readout for microtubule drug action. Cancer cells depend on mitotic spindle assembly, which involves gamma-tubulin-dependent pathways.
Neurodegeneration and Microtubule Dysfunction
Microtubule-associated proteins such as tau are implicated in neurodegenerative diseases, and tubulin-dependent ATPase activity is measured in brain microtubule preparations. S100 protein, which inhibits the activity, is a calcium-binding protein with roles in neurobiology. Therefore, dysregulation of tubulin-dependent ATPase activity may be relevant to neurodegeneration research.
From tubulin-dependent ATPase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does tubulin dimer accelerate ATP hydrolysis? | In vitro ATPase assay with purified tubulin and knockout of tubulin genes |
| How does taxol affect tubulin-dependent ATPase activity? | Point mutation in tubulin drug-binding site followed by ATPase assay |
| What is the role of S100 in regulating the activity? | Knockout or overexpression of S100B in microtubule protein preparations |
| Does gamma-tubulin-dependent assembly require this activity? | Knockout of TUBG1 in C. elegans |
| Can preventing tubulin/aldose reductase association delay diabetes? | Knock-in of AKR1B1 mutation in diabetic rat models |
| What is the kinetic role of tubulin in ADP release? | Tagged knock-in of tubulin with fluorescent ATP analogs |
How to Study the tubulin-dependent ATPase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| ATPase assay | ADP and phosphate release from ATP | Measure tubulin-dependent ATPase activity |
| Kinetic analysis | Rate of ADP release | Determine tubulin acceleration of product release |
| SDS-PAGE/Western blot | Protein composition of microtubule preparations | Verify tubulin and MAPs |
| Pharmacological stimulation | Effect of taxol/vinblastine | Test microtubule-targeting agents |
| Inhibition assay | Effect of S100 or PS-K | Identify negative regulators |
| RNAi/knockout | Gene requirement for activity | Test tubulin or gamma-tubulin dependence |
| Fluorescence microscopy | Microtubule and centrosome morphology | Assess aster assembly |
| Diabetic rat model | Tubulin/aldose reductase association | Test prevention of complications |
ATPase Activity Assays
Tubulin-dependent ATPase activity is typically measured by monitoring the release of ADP and phosphate from ATP in the presence of tubulin dimers. These assays can be used to test the effects of taxol, vinblastine, S100 protein, and PS-K. Kinetic analysis can determine whether tubulin accelerates product release.
Microtubule Protein Preparation
Porcine brain microtubule proteins are a classic source for measuring tubulin-dependent ATPase activity. Preparations contain tubulin dimers and microtubule-associated proteins, allowing assessment of the activity in a near-native context. Purity and composition can be verified by SDS-PAGE and Western blotting.
Pharmacological Modulation
Taxol and vinblastine are used to stimulate tubulin-dependent ATPase activity, while S100 protein and PS-K are used to inhibit it. Dose-response experiments can reveal the sensitivity of the activity to microtubule polymerization state. These methods are useful for screening compounds that target microtubules.
Genetic and Imaging Approaches
Knockout or knockdown of tubulin genes can test the requirement for tubulin dimers in the ATPase reaction. Gamma-tubulin-dependent centrosomal aster assembly can be studied by RNAi or knockout in C. elegans followed by imaging. Fluorescence microscopy can visualize microtubule structures in cells with altered ATPase activity.
How CRISPR Can Be Used to Study GO:0070463 tubulin-dependent ATPase activity
Knockout
CRISPR knockout of tubulin genes (TUBA, TUBB) can be used to test whether tubulin dimers are required for ATPase activity in cells. Knockout of TUBG1 can assess gamma-tubulin-dependent centrosomal aster assembly. Knockout of S100B can determine its role as a negative regulator.
Point Mutation
Point mutations in tubulin drug-binding sites can reveal how taxol or vinblastine stimulate tubulin-dependent ATPase activity. Mutations in AKR1B1 can disrupt tubulin/aldose reductase association and test effects on diabetic complications. Point mutations in S100B can map its inhibitory domain.
Knock-in
Knock-in of fluorescent tags on tubulin can enable live-cell imaging of microtubule dynamics and ATPase-dependent processes. Knock-in of disease-associated mutations in MAPT can model tauopathy and its effect on tubulin-dependent ATPase activity. Knock-in of AKR1B1 variants can test their role in diabetes.
Overexpression
Overexpression of S100B can test its inhibitory effect on tubulin-dependent ATPase activity in cells. Overexpression of gamma-tubulin can enhance centrosomal aster assembly and related ATPase activity. Overexpression of PS-K target proteins can modulate the activity.
How EDITGENE Supports tubulin-dependent ATPase activity Research
Researchers studying tubulin-dependent ATPase activity-related genes often need to determine whether a candidate gene is causally involved in microtubule dynamics, ATP hydrolysis, or disease pathology. EDITGENE provides CRISPR-based cell models and screening services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for tubulin-dependent ATPase activity research.
Frequently Asked Questions About tubulin-dependent ATPase activity
What is tubulin-dependent ATPase activity?
It is a molecular function (GO:0070463) where ATP is hydrolyzed to ADP and phosphate, and a tubulin dimer is required to accelerate the release of ADP and phosphate.
What genes are involved in tubulin-dependent ATPase activity?
Genes encoding tubulin (TUBA, TUBB), gamma-tubulin (TUBG1), S100 proteins, and aldose reductase (AKR1B1) are implicated in this activity or its regulation.
How is tubulin-dependent ATPase activity measured?
It is typically measured by ATPase assays that monitor ADP and phosphate release in the presence of tubulin dimers, often using porcine brain microtubule proteins.
What stimulates tubulin-dependent ATPase activity?
Taxol and vinblastine stimulate this activity in microtubule proteins from porcine brain.
What inhibits tubulin-dependent ATPase activity?
S100 protein and protein-bound polysaccharide PS-K inhibit this activity.
Is tubulin-dependent ATPase activity related to cancer?
Microtubule-targeting agents used in cancer therapy stimulate this activity, suggesting it may serve as a pharmacodynamic readout.
What is the role of gamma-tubulin in this activity?
Gamma-tubulin-dependent pathways are kinetically dominant for centrosomal aster assembly in C. elegans, linking to microtubule organization.
How does diabetes relate to tubulin-dependent ATPase activity?
Tubulin/aldose reductase association is linked to diabetic complications, and preventing this interaction delays pathology in rats.
Can CRISPR be used to study tubulin-dependent ATPase activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models can test the role of tubulin, S100, and AKR1B1 in this activity.
What model systems are used for tubulin-dependent ATPase activity research?
Porcine brain microtubule proteins, C. elegans, and diabetic rat models are commonly used.
Conclusion
GO:0070463 tubulin-dependent ATPase activity is a specialized molecular function in which ATP hydrolysis is accelerated by a tubulin dimer. It is modulated by microtubule-targeting drugs and endogenous factors, and it connects to centrosomal assembly and diabetic complications. Researchers can study this activity using biochemical assays, genetic models, and CRISPR-based approaches to uncover its roles in health and disease.
References
- 1. Fujii T et al.. 1983. Stimulation of tubulin-dependent ATPase activity in microtubule proteins from porcine brain by taxol.. J Neurochem 41(3):716-22 PMID: 6135758
- 2. Fujii T et al.. 1982. Stimulation of tubulin-dependent ATPase activity in microtubule proteins from porcine brain by vinblas tine.. J Neurochem 39(6):1587-93 PMID: 6216323
- 3. Asai H et al.. 1988. Inhibition of tubulin-dependent ATPase activity in microtubule proteins from porcine brain by S100 protein.. Neurochem Int 13(4):509-16 PMID: 20501311
- 4. Fujii T et al.. 1985. Interaction of protein-bound polysaccharide (PS-K) with microtubule proteins. V. Influence on tubulin-dependent adenosine triphosphatase (ATPase) activity.. Chem Pharm Bull (Tokyo) 33(4):1537-43 PMID: 2931190
- 5. Rivelli Antonelli JF et al.. 2021. Prevention of tubulin/aldose reductase association delays the development of pathological complications in diabetic rats.. J Physiol Biochem 77(4):565-576 PMID: 34097242
- 6. Hannak E et al.. 2002. The kinetically dominant assembly pathway for centrosomal asters in Caenorhabditis elegans is gamma-tubulin dependent.. J Cell Biol 157(4):591-602 PMID: 12011109
