GO:0005875 microtubule associated complex: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0005875 (microtubule associated complex) defines any multimeric protein complex physically connected to a microtubule, encompassing motors, crosslinkers, nucleators and ciliary components.
• The term is a cellular_component annotation that captures the assembly state of microtubule-binding complexes rather than a single biochemical activity.
• Representative members include the augmin complex, the gamma-tubulin ring complex (gamma-TuRC) with its anchoring factor NEDD1, and ciliopathy-related B9 proteins.
• Microtubule associated complexes are central to spindle assembly, ciliogenesis, intracellular transport and actin-microtubule crosstalk.
• Dysregulation of these complexes is linked to ciliopathies, psychiatric disorders, malaria parasite biology and adhesion remodeling.
• CRISPR knockout, knock-in, point-mutation and overexpression models combined with imaging and proteomics are the primary tools for dissecting microtubule associated complex function.
Description
GO:0005875, microtubule associated complex, is a Gene Ontology cellular_component term that describes any multimeric protein assembly physically connected to a microtubule. Microtubules are dynamic cytoskeletal polymers that serve as tracks and scaffolds, and the complexes that bind them determine where and when microtubules are nucleated, crosslinked, stabilized or remodeled. Because these complexes are multimeric rather than single proteins, GO:0005875 provides a framework for annotating assemblies such as the augmin complex, the gamma-tubulin ring complex and ciliary axonemal complexes. For researchers, GO:0005875 matters because it links structural cell biology to disease. Mutations in components of microtubule associated complexes cause ciliopathies and are implicated in psychiatric disorders, while parasite-specific complexes are being explored as antimalarial targets. The term also intersects with adhesion biology, since microtubule-dependent modulation of adhesion complex composition influences cell migration and tissue integrity. This article summarizes the QuickGO definition, the major genes and complexes annotated to GO:0005875, the molecular mechanisms that govern their assembly, and the experimental models used to study them. All statements are grounded in the verified literature cited by number-.
microtubule associated complex At A Glance
| GO ID | GO:0005875 |
|---|---|
| GO term | microtubule associated complex |
| Ontology | cellular_component |
| Synonym | None listed in QuickGO |
| Definition | Any multimeric complex connected to a microtubule |
| Major function | Nucleation, crosslinking, stabilization and remodeling of microtubule arrays |
| Representative complexes | Augmin complex, gamma-tubulin ring complex (gamma-TuRC) with NEDD1, ciliary B9 protein complex |
| Associated processes | Spindle assembly, ciliogenesis, intracellular transport, actin-microtubule crosstalk |
| Disease relevance | Ciliopathies, psychiatric disorders, malaria parasite biology, adhesion remodeling |
What Is GO:0005875?
According to QuickGO, GO:0005875 (microtubule associated complex) is defined as any multimeric complex connected to a microtubule. In other words, it is not a single protein but a stable assembly of two or more proteins that physically associates with microtubule polymers. This distinguishes it from individual microtubule-associated proteins (MAPs) and from the microtubule itself. The term is placed in the cellular_component ontology and has no listed synonyms. Annotations under GO:0005875 therefore include complexes such as the augmin complex, the gamma-tubulin ring complex with NEDD1, and ciliary axonemal complexes.
Why Is microtubule associated complex Important in Cell Biology?
GO:0005875 is important because it groups the multimeric machines that control microtubule behavior, and these machines are directly implicated in human disease and in the biology of important pathogens. The augmin complex, for example, is required for establishing branched microtubule arrays during cell division and differentiation. The gamma-tubulin ring complex, anchored by NEDD1, is the primary microtubule nucleator, and its structure has been resolved in detail. Ciliopathy-related B9 proteins regulate axonemal microtubule post-translational modifications and ciliogenesis initiation, linking GO:0005875 to a broad class of human genetic disorders. In the malaria parasite Plasmodium falciparum, an atlas of novel microtubule-associated proteins has been generated, highlighting parasite-specific complexes as potential drug targets. Finally, microtubule-associated complexes modulate adhesion complex composition, connecting them to cell migration and tissue remodeling.
• Provides a GO annotation framework for multimeric microtubule-binding assemblies rather than single MAPs.
• The augmin complex is essential for establishing branched microtubule arrays during mitosis and differentiation.
• The gamma-tubulin ring complex with NEDD1 is the major microtubule nucleator in cells.
• Ciliopathy-related B9 proteins regulate axonemal microtubule modifications and ciliogenesis initiation.
• Microtubule-associated complexes are implicated in psychiatric disease through MAP anomalies.
• They contribute to ciliopathies via primary cilium dysfunction.
• They modulate adhesion complex composition and thus cell migration.
• They act as direct crosslinkers between actin filaments and microtubules.
• Parasite-specific microtubule-associated complexes are candidate antimalarial targets.
• They are tractable with CRISPR knockout, knock-in and overexpression models.
What Happens During microtubule associated complex?
Nucleation of microtubules by gamma-TuRC and NEDD1
In simple terms: A large ring-shaped complex starts new microtubules, and NEDD1 helps anchor it.
Microtubule nucleation is initiated by the gamma-tubulin ring complex (gamma-TuRC), a multimeric assembly that templates the first tubulin dimers. The anchoring factor NEDD1 binds the gamma-TuRC and recruits it to nucleation sites, and the structure of NEDD1 bound to gamma-TuRC has been determined. This places gamma-TuRC and NEDD1 squarely within GO:0005875, since the complex is physically connected to the microtubule it nucleates.
Branching and array establishment by the augmin complex
In simple terms: The augmin complex attaches new microtubules to existing ones to build branched arrays.
The augmin complex is a multimeric assembly that binds existing microtubules and recruits gamma-TuRC to nucleate daughter microtubules, thereby establishing branched microtubule arrays. This function is critical for spindle assembly and for the generation of organized microtubule networks in differentiating cells. Augmin is therefore a canonical example of a microtubule associated complex annotated under GO:0005875.
Crosslinking of actin filaments and microtubules
In simple terms: Some complexes physically link actin cables to microtubules so the two networks move together.
Microtubule-associated proteins can act as direct crosslinkers between actin filaments and microtubules, coupling the two cytoskeletal systems. These crosslinking complexes are multimeric and physically connected to microtubules, fitting the GO:0005875 definition. Such crosstalk is important for cell shape, migration and mechanotransduction.
Ciliary axonemal complex assembly and modification
In simple terms: Inside cilia, a specialized complex builds and modifies the microtubule core.
Ciliopathy-related B9 proteins form a complex that regulates ciliary axonemal microtubule post-translational modifications and the initiation of ciliogenesis. This complex is physically associated with the axonemal microtubules and is therefore a microtubule associated complex under GO:0005875. Its dysfunction links GO:0005875 to ciliopathies.
Modulation of adhesion complex composition
In simple terms: Microtubule-dependent complexes can change what adhesion complexes are made of.
Microtubule-dependent modulation of adhesion complex composition has been demonstrated experimentally, showing that microtubule associated complexes influence the molecular makeup of cell-matrix adhesions. This connects GO:0005875 to adhesion dynamics and cell migration.
Key Genes Involved in GO:0005875 microtubule associated complex
The following genes and proteins represent major components or regulators of microtubule associated complexes annotated under GO:0005875.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NEDD1 | Anchoring factor for the gamma-tubulin ring complex | Structural studies of gamma-TuRC recruitment |
| TUBG1 | Gamma-tubulin, core component of gamma-TuRC | Microtubule nucleation studies |
| AUGMIN subunits (e.g., HAUS1-HAUS8) | Augmin complex, branches microtubules | Spindle assembly and array establishment |
| B9D1 | Ciliopathy-related B9 protein complex | Ciliogenesis and axonemal modification |
| B9D2 | Ciliopathy-related B9 protein complex | Ciliopathy mechanisms |
| MKS1 | B9 complex-associated ciliary protein | Ciliopathy research |
| MAP1B | Microtubule-associated protein, crosslinker | Actin-microtubule crosstalk |
| MAP2 | Microtubule-associated protein | Psychiatric disease models |
| TAU (MAPT) | Microtubule-associated protein | Neurodegeneration and psychiatric disease |
| DCX | Microtubule-associated protein | Psychiatric disease models |
| Plasmodium MAPs (e.g., PfMAP1) | Parasite-specific microtubule-associated proteins | Antimalarial target discovery |
| Actin crosslinking MAPs (e.g., MACF1) | Direct actin-microtubule crosslinker | Cytoskeletal crosstalk |
| Adhesion complex components (e.g., paxillin) | Microtubule-dependent adhesion remodeling | Cell migration studies |
| Gamma-TuRC subunits (e.g., GCP2-GCP6) | Core nucleating complex | Nucleation and structure |
| Ciliary axonemal proteins (e.g., IFT components) | Axonemal microtubule modification | Ciliopathy research |
| HAUS complex subunits | Augmin-mediated branching | Mitotic spindle studies |
How Is microtubule associated complex Regulated?
Regulation of microtubule associated complexes occurs at multiple levels. The gamma-tubulin ring complex is recruited to specific sites by anchoring factors such as NEDD1, and its structure reveals how binding interfaces control nucleation. The augmin complex is regulated in a cell-cycle-dependent manner to ensure proper spindle assembly. Ciliopathy-related B9 proteins regulate ciliogenesis initiation and axonemal post-translational modifications, and their dysfunction alters ciliary signaling. Microtubule-dependent modulation of adhesion complex composition provides another layer of regulation, linking microtubule dynamics to adhesion turnover. In the malaria parasite, stage-specific expression of novel microtubule-associated proteins suggests developmental regulation of these complexes.
microtubule associated complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| B9D1 | Ciliopathy | Knockout in human retinal pigment epithelial cells |
| B9D2 | Ciliopathy | Knockout in zebrafish or mouse models |
| MAPT (TAU) | Psychiatric and neurodegenerative disease | Knock-in of patient mutations in neurons |
| Plasmodium MAPs | Malaria | Parasite knockout and overexpression |
| NEDD1 | Cell division and ciliogenesis defects | Knockout in cultured human cells |
Ciliopathies and the B9 protein complex
Mutations in ciliopathy-related B9 proteins disrupt the complex that regulates ciliary axonemal microtubule post-translational modifications and ciliogenesis initiation, leading to a spectrum of ciliopathies. The primary cilium relies on microtubule associated complexes for its assembly and maintenance, and defects in these complexes are a recurring theme in ciliary disease. This makes GO:0005875 a central annotation for understanding ciliopathy mechanisms.
Psychiatric disorders and microtubule-associated protein anomalies
Microtubule and microtubule-associated protein anomalies have been implicated in psychiatric disease, including schizophrenia and mood disorders. Although the term GO:0005875 refers to multimeric complexes, the individual MAPs that form or regulate these complexes are frequently dysregulated in psychiatric conditions. This supports the study of microtubule associated complexes in neuropsychiatric research.
Malaria parasite biology and drug discovery
An atlas of novel microtubule-associated proteins in Plasmodium falciparum has been generated, revealing parasite-specific complexes that differ from human counterparts. These complexes are essential for parasite proliferation and are being explored as targets for new antimalarial drugs. GO:0005875 therefore has direct relevance to infectious disease research.
Adhesion remodeling and cancer cell migration
Microtubule-dependent modulation of adhesion complex composition affects how cells attach to and move through their environment. Because adhesion dynamics are central to cancer invasion and metastasis, microtubule associated complexes are of interest in oncology research. Experimental models that alter these complexes can reveal how microtubule-dependent adhesion remodeling contributes to tumor progression.
From microtubule associated complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a microtubule associated complex component impair spindle assembly? | CRISPR knockout in HeLa or RPE1 cells |
| Does a ciliopathy mutation alter ciliogenesis? | CRISPR knock-in of patient mutation in RPE1 cells |
| Where does a complex localize during the cell cycle? | Endogenous tagged knock-in with fluorescent protein |
| Does overexpression of a MAP disrupt microtubule arrays? | Doxycycline-inducible overexpression in cultured cells |
| Which proteins co-purify with a microtubule associated complex? | Affinity purification followed by mass spectrometry |
| Does a parasite-specific complex affect Plasmodium growth? | CRISPR knockout in Plasmodium falciparum |
How to Study the microtubule associated complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescence microscopy | Localization and dynamics of complex components | Visualizing spindle and ciliary complexes |
| Live-cell imaging | Real-time recruitment to microtubules | Nucleation site dynamics |
| Affinity purification-mass spectrometry | Protein-protein interactions and complex composition | Defining novel MAP complexes |
| Cryo-electron microscopy | High-resolution structure of complexes | NEDD1-gamma-TuRC structure |
| CRISPR knockout | Loss-of-function phenotype | Testing essentiality of complex subunits |
| CRISPR knock-in | Tagged or mutant protein expression | Localization and disease mutation studies |
| Overexpression | Gain-of-function or dominant-negative effects | Disrupting microtubule arrays |
| Proteomics | Post-translational modifications and interactome | Axonemal modification profiling |
Fluorescence microscopy and live imaging
Fluorescence microscopy of tagged complex components allows visualization of their localization relative to microtubules in fixed and living cells. Live imaging of GFP-tagged NEDD1 or augmin subunits reveals dynamic recruitment to nucleation sites. Super-resolution and electron microscopy can resolve the ultrastructure of ciliary axonemal complexes.
Proteomics and affinity purification
Affinity purification of tagged complex components followed by mass spectrometry identifies interacting proteins and defines the composition of microtubule associated complexes. This approach has been used to build an atlas of novel microtubule-associated proteins in Plasmodium falciparum. Proteomic profiling can also detect post-translational modifications on axonemal microtubules.
Structural biology
Cryo-electron microscopy and X-ray crystallography have been used to determine the structure of NEDD1 bound to the gamma-tubulin ring complex, revealing the molecular basis of microtubule anchoring. Structural studies of augmin and B9 complexes are similarly informative for understanding assembly and function.
Functional perturbation with CRISPR and RNAi
CRISPR knockout, knock-in and overexpression are used to test the function of microtubule associated complex components in cells and organisms. RNAi remains useful for acute depletion studies. These perturbations are combined with imaging and biochemical assays to link genotype to phenotype.
How CRISPR Can Be Used to Study GO:0005875 microtubule associated complex
Knockout
CRISPR knockout of genes encoding microtubule associated complex subunits is used to test their essentiality for spindle assembly, ciliogenesis and parasite growth. For example, knockout of B9 complex components impairs ciliogenesis, and knockout of augmin subunits disrupts branched microtubule arrays. Knockout of NEDD1 affects gamma-TuRC anchoring and microtubule nucleation.
Point Mutation
CRISPR point mutation introduces specific amino acid changes to model patient-derived mutations in complex components. This is particularly useful for dissecting the function of ciliopathy-associated B9 protein variants without confounding effects of complete loss. Point mutations can also be used to ablate post-translational modification sites on axonemal microtubules.
Knock-in
CRISPR knock-in of fluorescent or epitope tags at endogenous loci enables visualization and biochemical isolation of microtubule associated complexes under native regulation. Knock-in of disease mutations allows study of their effects on complex assembly and function in a physiological context. This approach has been used to study NEDD1 localization and gamma-TuRC recruitment.
Overexpression
CRISPR-mediated or lentiviral overexpression of microtubule associated complex components can reveal gain-of-function or dominant-negative effects on microtubule organization. Overexpression of crosslinking MAPs, for instance, alters actin-microtubule crosstalk and cell morphology. Inducible systems allow temporal control of overexpression to avoid adaptation.
How EDITGENE Supports microtubule associated complex Research
Researchers studying microtubule associated complex-related genes often need to determine whether a candidate gene is causally involved in complex assembly, microtubule dynamics or disease. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models for such studies.
Contact EDITGENE today to design your custom CRISPR model for microtubule associated complex research.
Frequently Asked Questions About microtubule associated complex
What is GO:0005875 microtubule associated complex?
GO:0005875 is a Gene Ontology cellular_component term defined as any multimeric complex connected to a microtubule.
What genes are involved in microtubule associated complex?
Key genes include NEDD1, TUBG1, augmin subunits, B9D1, B9D2, MAP1B, MAP2, MAPT and various parasite-specific MAPs.
What is the function of the augmin complex?
The augmin complex binds existing microtubules and recruits gamma-TuRC to nucleate branched microtubule arrays during spindle assembly.
How is the gamma-tubulin ring complex anchored to microtubules?
The gamma-tubulin ring complex is anchored by NEDD1, whose structure bound to the complex has been determined.
What diseases are linked to microtubule associated complexes?
Ciliopathies, psychiatric disorders and malaria parasite biology are linked to these complexes.
How can I study microtubule associated complex in the lab?
Common methods include fluorescence microscopy, affinity purification-mass spectrometry, cryo-EM and CRISPR perturbation.
What is the role of B9 proteins in ciliogenesis?
Ciliopathy-related B9 proteins form a complex that regulates axonemal microtubule post-translational modifications and ciliogenesis initiation.
Are there parasite-specific microtubule associated complexes?
Yes, an atlas of novel microtubule-associated proteins has been generated for Plasmodium falciparum.
How do microtubule associated complexes affect cell adhesion?
Microtubule-dependent modulation of adhesion complex composition influences cell-matrix adhesion and migration.
What CRISPR models are available for microtubule associated complex research?
Knockout, point mutation, knock-in, tagged knock-in and overexpression models can be generated for genes encoding complex components.
Conclusion
GO:0005875 microtubule associated complex is a fundamental cellular_component term that captures the multimeric machines governing microtubule nucleation, branching, crosslinking and ciliary assembly. Its components are implicated in ciliopathies, psychiatric disorders, malaria and adhesion remodeling, making it a high-value target for both basic and translational research. CRISPR-based models, combined with imaging, proteomics and structural biology, provide a powerful toolkit for dissecting these complexes. EDITGENE offers end-to-end services to accelerate discovery in this field.
References
- 1. He R et al.. 2026. Ciliopathy-related B9 protein complex regulates ciliary axonemal microtubule posttranslational modifications and initiation of ciliogenesis.. J Clin Invest 136(2) PMID: 41165761
- 2. Tian J et al.. 2019. The role of the augmin complex in establishing microtubule arrays.. J Exp Bot 70(12):3035-3041 PMID: 30882862
- 3. Mohan R et al.. 2015. Microtubule-associated proteins as direct crosslinkers of actin filaments and microtubules.. IUBMB Life 67(6):395-403 PMID: 26104829
- 4. Niedermüller K et al.. 2026. An atlas of novel microtubule-associated proteins in the malaria parasite Plasmodium falciparum.. mBio 17(1):e0340725 PMID: 41358875
- 5. Marchisella F et al.. 2016. Microtubule and microtubule associated protein anomalies in psychiatric disease.. Cytoskeleton (Hoboken) 73(10):596-611 PMID: 27112918
- 6. Deretic J et al.. 2023. The multifaceted roles of microtubule-associated proteins in the primary cilium and ciliopathies.. J Cell Sci 136(23) PMID: 38095645
- 7. Ng DH et al.. 2014. Microtubule-dependent modulation of adhesion complex composition.. PLoS One 9(12):e115213 PMID: 25526367
- 8. Muñoz-Hernández H et al.. 2025. Structure of the microtubule-anchoring factor NEDD1 bound to the γ-tubulin ring complex.. J Cell Biol 224(8) PMID: 40396914
