GO:0008017 microtubule binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008017 microtubule binding is a molecular function defined as binding to a microtubule, a filament composed of tubulin monomers.
• Key microtubule-binding proteins include end-binding proteins (EB1, EB2, EB3), tau, MAP65-1, APC, katanin, and SKAP, which regulate microtubule dynamics, bundling, severing, and kinetochore attachment.
• Microtubule binding is essential for diverse cellular processes such as mitosis, intracellular transport, and neuronal development, and its dysregulation is linked to cancer and neurodegeneration.
• EB1 tip tracking depends on rapid binding to protofilament edge sites and dimeric organization, which can be modulated by phosphorylation.
• Tau's microtubule-binding repeats share partial mimicry with its membrane-binding region, suggesting dual regulation.
• CRISPR-based models (knockout, point mutation, knock-in, overexpression) enable precise dissection of microtubule-binding protein functions in health and disease.
Description
Microtubules are dynamic polymers of tubulin that form the cytoskeleton and are essential for cell shape, division, and intracellular transport. The molecular function of binding to these filaments, annotated as GO:0008017 microtubule binding, is performed by a diverse set of proteins that interact with microtubules to regulate their stability, dynamics, and organization. This function is critical for processes ranging from mitotic spindle assembly to neuronal morphogenesis, and its perturbation is associated with cancer and neurodegenerative disorders. Researchers study microtubule binding to understand fundamental cell biology and to develop therapeutic strategies targeting microtubule-associated proteins.
microtubule binding At A Glance
| GO ID | GO:0008017 |
|---|---|
| GO term | microtubule binding |
| Ontology | molecular_function |
| Synonym | microtubule/chromatin interaction; microtubule severing activity |
| Definition | Binding to a microtubule, a filament composed of tubulin monomers. |
| Major function | Direct interaction with microtubule polymers to regulate dynamics, stability, and organization. |
| Related processes | Mitosis, intracellular transport, neuronal development, cytoskeletal organization. |
| Key proteins | EB1, EB2, EB3, tau, MAP65-1, APC, katanin, SKAP. |
What Is GO:0008017?
GO:0008017 microtubule binding is defined as the binding to a microtubule, a filament composed of tubulin monomers. It is a molecular function term in the Gene Ontology, encompassing proteins that directly interact with microtubule polymers. Synonyms include microtubule/chromatin interaction and microtubule severing activity, reflecting the diverse contexts in which this binding occurs.
Why Is microtubule binding Important in Cell Biology?
Microtubule binding is fundamental to cellular architecture and dynamics, influencing processes such as cell division, vesicle trafficking, and neuronal outgrowth. Proteins that bind microtubules are often deregulated in diseases, including cancer and neurodegeneration, making this function a key area for therapeutic intervention.
• Regulates microtubule dynamics and stability, essential for mitosis and intracellular transport.
• Involved in neuronal development and maintenance; tau microtubule binding is linked to Alzheimer's disease.
• EB1 family proteins are key regulators of microtubule plus-end tracking and are implicated in cancer.
• APC, a tumor suppressor, scaffolds microtubule end-binding proteins and is mutated in colorectal cancer.
• Katanin severing activity is modulated by MAP65-1 bundling, affecting microtubule organization.
• SKAP binding to microtubules reduces friction at kinetochores, ensuring proper chromosome segregation.
• Microtubule-binding proteins are targets for anti-cancer drugs that disrupt mitosis.
• Understanding microtubule binding aids in designing CRISPR models for functional studies and drug discovery.
Molecular Mechanism of microtubule binding
Recognition of microtubule lattice and ends
In simple terms: Proteins find and attach to specific spots on the microtubule surface.
Microtubule-binding proteins recognize distinct features of the microtubule lattice, including protofilament edges and plus-ends. EB1, for example, rapidly binds to protofilament edge sites to facilitate tip tracking at growing microtubule plus-ends. This recognition is mediated by structural elements such as the calponin homology domain in EB proteins and the microtubule-binding repeats in tau.
Binding affinity and dimerization
In simple terms: How tightly a protein sticks to microtubules can depend on whether it pairs up with itself.
The microtubule end-binding affinity of EB1 is enhanced by a dimeric organization that is susceptible to phosphorylation. Dimerization allows cooperative binding and increases residence time at microtubule ends, which is crucial for EB1's role in regulating microtubule dynamics.
Regulation by phosphorylation
In simple terms: Adding phosphate groups can change how proteins interact with microtubules.
Phosphorylation of EB1 modulates its dimerization and microtubule-binding affinity, thereby influencing microtubule dynamics. This post-translational modification provides a switch to rapidly alter microtubule interactions in response to cellular signals.
Competition and modulation by other MAPs
In simple terms: Other proteins can block or enhance the ability of a protein to bind microtubules.
Microtubule bundling by MAP65-1 protects against severing by inhibiting the binding of katanin. This illustrates how the interplay between different microtubule-associated proteins (MAPs) can modulate access to the microtubule surface and regulate severing activity.
Scaffolding and complex assembly
In simple terms: Some proteins act as platforms to bring other microtubule binders together.
Adenomatous Polyposis Coli (APC) acts as a scaffold for microtubule end-binding proteins, facilitating their localization and function at microtubule plus-ends. This scaffolding is important for processes such as cell migration and chromosome segregation.
Force-dependent stabilization at kinetochores
In simple terms: Proteins can strengthen their grip on microtubules when pulled.
SKAP binding to microtubules reduces friction at the kinetochore-microtubule interface and increases attachment stability under force. This force-dependent stabilization is critical for accurate chromosome segregation during mitosis.
Key Genes Involved in GO:0008017 microtubule binding
The following genes encode proteins that directly bind microtubules and are central to the function of GO:0008017.
| Gene | Major Role | Research Relevance |
|---|---|---|
| MAPRE1 (EB1) | Plus-end tracking protein; regulates microtubule dynamics | Cancer, mitosis, cell migration |
| MAPRE2 (EB2) | Plus-end tracking protein; regulates microtubule dynamics | Cancer, neuronal development |
| MAPRE3 (EB3) | Plus-end tracking protein; regulates microtubule dynamics | Neuronal development, cancer |
| MAPT (Tau) | Microtubule stabilization; axonal transport | Alzheimer's disease, tauopathies |
| APC | Scaffold for microtubule end-binding proteins | Colorectal cancer, mitosis |
| KATNA1 (Katanin) | Microtubule severing | Mitosis, neuronal development |
| MAP65-1 (plant) | Microtubule bundling; protects against severing | Plant cell biology |
| SKAP1/2 | Kinetochore-microtubule attachment | Mitosis, chromosome segregation |
| CLASP1/2 | Microtubule plus-end tracking; promotes rescue | Mitosis, neuronal development |
| STMN1 (Stathmin) | Microtubule destabilization | Cancer, neuronal development |
| DCX | Microtubule stabilization; neuronal migration | Lissencephaly, epilepsy |
| KIF11 (Eg5) | Mitotic kinesin; crosslinks microtubules | Cancer, mitosis |
| DYNC1H1 | Dynein heavy chain; retrograde transport | Neurodegeneration, motor neuron disease |
| TUBB | Tubulin beta; microtubule subunit | Cancer, tubulinopathies |
| TUBA1A | Tubulin alpha; microtubule subunit | Tubulinopathies, brain malformations |
| MAP1B | Microtubule-associated protein; neuronal development | Neurodegeneration |
| MAP2 | Microtubule stabilization in dendrites | Neurodegeneration |
How Is microtubule binding Regulated?
Microtubule binding is regulated by post-translational modifications such as phosphorylation, which can alter the affinity of proteins like EB1 for microtubule ends. Additionally, interactions with other MAPs, such as MAP65-1 inhibiting katanin binding, provide competitive regulation. The dimeric state of EB1, which enhances its microtubule end-binding affinity, is also subject to phosphorylation, offering a dynamic control mechanism.
microtubule binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| APC | Colorectal cancer | Knockout in HCT116 cells; knock-in of patient mutations |
| MAPT | Alzheimer's disease, tauopathies | Point mutation knock-in in iPSCs; overexpression in neurons |
| TUBA1A | Tubulinopathies, brain malformations | Knock-in of patient mutations in neural progenitors |
| MAPRE1 (EB1) | Cancer, mitotic defects | Knockout in HeLa cells; overexpression in cancer cell lines |
| SKAP1/2 | Chromosome segregation errors | Knockout in RPE1 cells; tagged knock-in for imaging |
Cancer
Dysregulation of microtubule-binding proteins is frequently observed in cancer. EB1 overexpression promotes microtubule dynamics and is associated with tumor progression. APC, a scaffold for microtubule end-binding proteins, is a well-known tumor suppressor mutated in colorectal cancer. Targeting microtubule-binding proteins is a strategy for anti-mitotic cancer therapies.
Neurodegeneration
Tau, a microtubule-binding protein, forms neurofibrillary tangles in Alzheimer's disease and other tauopathies. Its microtubule-binding repeats are crucial for stabilizing neuronal microtubules, and their dysfunction contributes to neurodegeneration. Other microtubule-binding proteins, such as MAP1B and MAP2, are also implicated in neuronal maintenance.
Developmental disorders
Mutations in tubulin genes (TUBA1A, TUBB) and microtubule-associated proteins like DCX cause brain malformations such as lissencephaly and microcephaly, highlighting the importance of microtubule binding in cortical development.
From microtubule binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of EB1 affect microtubule dynamics? | EB1 knockout in HeLa cells |
| How does tau phosphorylation affect microtubule binding? | Tau point mutations (e.g., S262A) knock-in in neurons |
| What is the role of APC scaffolding in mitosis? | APC knockout in HCT116 cells |
| How does SKAP force-dependent binding stabilize kinetochores? | SKAP knockout in RPE1 cells; tagged knock-in |
| Can katanin severing be modulated by MAP65-1? | MAP65-1 overexpression in plant cells |
| Does EB1 dimerization affect plus-end tracking? | EB1 dimerization mutants knock-in |
How to Study the microtubule binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell imaging | Microtubule dynamics and protein localization | EB1 tip tracking |
| TIRF microscopy | Binding kinetics at single-molecule level | EB1-microtubule interactions |
| Co-sedimentation assay | Binding affinity to microtubules | Tau-microtubule binding |
| Cryo-EM | High-resolution structure of protein-microtubule complexes | EB1-microtubule interface |
| CRISPR knockout screens | Gene essentiality and pathway identification | Mitotic regulators |
| Phosphorylation assays | Post-translational modifications | EB1 regulation |
| Katanin severing assay | Microtubule severing activity | MAP65-1 protection |
| Force measurements | Attachment stability under tension | SKAP at kinetochores |
Live-cell imaging of microtubule dynamics
Fluorescently tagged microtubule-binding proteins (e.g., EB1-GFP) and tubulin can be imaged in live cells to track plus-end dynamics and protein localization. This method reveals real-time binding kinetics and tip tracking.
In vitro microtubule binding assays
Purified proteins can be tested for binding to polymerized microtubules using co-sedimentation or total internal reflection fluorescence (TIRF) microscopy. These assays quantify affinity and competition.
Cryo-electron microscopy
Seeded microtubule growth for cryo-EM allows visualization of end-binding proteins on microtubules at near-atomic resolution, providing structural insights into binding interfaces.
CRISPR-based genetic screens
Genome-wide knockout or activation screens can identify genes that modulate microtubule binding and related phenotypes, such as mitotic defects or drug resistance.
How CRISPR Can Be Used to Study GO:0008017 microtubule binding
Knockout
CRISPR knockout of microtubule-binding genes (e.g., MAPRE1, APC) enables loss-of-function studies to assess their roles in microtubule dynamics, mitosis, and disease. Knockout cell lines can be used for phenotypic screens and drug sensitivity tests.
Point Mutation
Introducing specific point mutations (e.g., in MAPT or TUBA1A) via CRISPR allows modeling of disease-associated variants and dissection of phosphorylation sites or binding interfaces.
Knock-in
Knock-in of tagged versions (e.g., GFP or HaloTag) of microtubule-binding proteins facilitates live-cell imaging and proteomic analysis while preserving endogenous regulation.
Overexpression
CRISPR activation or cDNA overexpression can elevate levels of microtubule-binding proteins to study gain-of-function effects, such as increased microtubule bundling or resistance to severing.
How EDITGENE Supports microtubule binding Research
Researchers studying microtubule binding-related genes often need to determine whether a candidate gene is causally involved in microtubule dynamics, disease progression, or drug response. EDITGENE provides comprehensive CRISPR services to generate precisely engineered cell models for such functional studies.
Contact EDITGENE today to design your custom CRISPR model for microtubule binding research.
Frequently Asked Questions About microtubule binding
What is GO:0008017 microtubule binding?
GO:0008017 is a Gene Ontology molecular function term defined as binding to a microtubule, a filament composed of tubulin monomers.
What genes are involved in microtubule binding?
Key genes include MAPRE1 (EB1), MAPRE2 (EB2), MAPRE3 (EB3), MAPT (tau), APC, KATNA1, SKAP1/2, and tubulins TUBA1A and TUBB.
How does EB1 bind to microtubules?
EB1 binds to protofilament edge sites at growing microtubule plus-ends, and its affinity is enhanced by dimerization and regulated by phosphorylation.
What is the role of tau in microtubule binding?
Tau stabilizes microtubules through its microtubule-binding repeats, and this function is critical for neuronal health; its dysfunction is linked to Alzheimer's disease.
How is microtubule binding regulated?
It is regulated by post-translational modifications such as phosphorylation, which can alter binding affinity, and by competition with other microtubule-associated proteins.
What diseases are associated with microtubule binding defects?
Cancer, neurodegeneration (e.g., Alzheimer's disease), and developmental disorders like lissencephaly are associated with defects in microtubule-binding proteins.
What methods are used to study microtubule binding?
Common methods include live-cell imaging, TIRF microscopy, co-sedimentation assays, cryo-EM, and CRISPR screens.
Can CRISPR be used to study microtubule binding?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models enable precise functional studies of microtubule-binding genes.
What is the difference between microtubule binding and microtubule severing?
Microtubule binding is the general function of binding to microtubules, while severing is a specific activity that cuts microtubules, often performed by proteins like katanin that also bind microtubules.
How does SKAP contribute to microtubule binding?
SKAP binds to microtubules at kinetochores, reducing friction and increasing attachment stability under force during mitosis.
Conclusion
GO:0008017 microtubule binding is a fundamental molecular function that underpins cytoskeletal dynamics, cell division, and neuronal development. Its dysregulation contributes to cancer, neurodegeneration, and developmental disorders. Advanced CRISPR models and imaging techniques continue to unravel the precise mechanisms and therapeutic potential of microtubule-binding proteins.
References
- 1. Nehlig A et al.. 2017. Regulation of end-binding protein EB1 in the control of microtubule dynamics.. Cell Mol Life Sci 74(13):2381-2393 PMID: 28204846
- 2. MacAinsh M et al.. 2023. Partial mimicry of the microtubule binding of tau by its membrane binding.. Protein Sci 32(3):e4581 PMID: 36710643
- 3. Song Y et al.. 2020. The microtubule end-binding affinity of EB1 is enhanced by a dimeric organization that is susceptible to phosphorylation.. J Cell Sci 133(9) PMID: 32152183
- 4. Burkart GM et al.. 2019. Microtubule bundling by MAP65-1 protects against severing by inhibiting the binding of katanin.. Mol Biol Cell 30(13):1587-1597 PMID: 31017848
- 5. Serre L et al.. 2019. Adenomatous Polyposis Coli as a Scaffold for Microtubule End-Binding Proteins.. J Mol Biol 431(10):1993-2005 PMID: 30959051
- 6. Gonzalez SJ et al.. 2024. Rapid binding to protofilament edge sites facilitates tip tracking of EB1 at growing microtubule plus-ends.. Elife 13 PMID: 38385657
- 7. Rosas-Salvans M et al.. 2025. SKAP binding to microtubules reduces friction at the kinetochore-microtubule interface and increases attachment stability under force.. Curr Biol 35(8):1805-1815.e4 PMID: 40154475
- 8. Maurer SP et al.. 2014. Seeded microtubule growth for cryoelectron microscopy of end-binding proteins.. Methods Mol Biol 1136:247-60 PMID: 24633800
