GO:0034676 integrin alpha6-beta4 complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0034676 (integrin alpha6-beta4 complex) is a heterodimeric cellular_component composed of one ITGA6 (alpha6) subunit and one ITGB4 (beta4) subunit.
• The complex is a laminin-binding adhesion receptor that links the extracellular matrix to the intermediate filament cytoskeleton through plectin and vimentin.
• Integrin alpha6-beta4 is a major epithelial adhesion receptor and is exploited by pathogens such as HPV16 for host cell entry.
• The complex can act as a signaling platform, forming ternary complexes with IGF1 and IGF1R under anchorage-independent conditions.
• Upregulation of ITGA6 and the alpha6-beta4 complex drives progression of hepatocellular carcinoma and other epithelial cancers.
• Autoantibodies against alpha6 and beta4 integrins are linked to complement activation and blistering skin diseases.
Description
The integrin alpha6-beta4 complex (GO:0034676) is a heterodimeric cell-surface adhesion receptor that belongs to the integrin family of extracellular matrix receptors. It is defined in QuickGO as an integrin complex that comprises one alpha6 subunit and one beta4 subunit. Unlike most integrins, which connect to the actin cytoskeleton, the alpha6-beta4 heterodimer is a laminin receptor that links the extracellular matrix to the intermediate filament system via plectin and vimentin. This unique cytoskeletal linkage makes it a central organizer of stable adhesion structures in stratified and simple epithelia. Researchers study GO:0034676 because it sits at the crossroads of cell adhesion, signal transduction, pathogen entry, and cancer progression. Its beta4 subunit has an unusually long cytoplasmic domain that serves as a scaffold for signaling molecules, enabling the complex to convert extracellular cues into intracellular responses. Consequently, the integrin alpha6-beta4 complex is a high-value target for functional genomics, disease modeling, and therapeutic discovery.
integrin alpha6-beta4 complex At A Glance
| GO ID | GO:0034676 |
|---|---|
| GO term | integrin alpha6-beta4 complex |
| Ontology | cellular_component |
| Synonym | alpha6-beta4 integrin complex; ITGA6-ITGB4 complex |
| Definition | An integrin complex that comprises one alpha6 subunit and one beta4 subunit. |
| Major function | Laminin-binding adhesion receptor linking the extracellular matrix to intermediate filaments and signaling platforms. |
| Subunits | ITGA6 (alpha6) and ITGB4 (beta4). |
| Key adaptors | Plectin and vimentin for adhesion complex distribution. |
| Disease links | Cancer progression, HPV16 entry, skin fragility syndromes, and autoimmune blistering diseases. |
What Is GO:0034676?
In our own words, GO:0034676 describes a specific integrin heterodimer found on the cell surface. It consists of exactly one alpha6 subunit (encoded by ITGA6) and one beta4 subunit (encoded by ITGB4). This complex is a cellular_component because it is a stable structural unit of the plasma membrane adhesion machinery. It binds laminin in the extracellular matrix and, through its beta4 cytoplasmic tail, recruits adaptor proteins such as plectin to connect to intermediate filaments. The complex is also known as the alpha6-beta4 integrin complex or the ITGA6-ITGB4 complex.
Why Is integrin alpha6-beta4 complex Important in Cell Biology?
The integrin alpha6-beta4 complex is important because it is a master regulator of epithelial adhesion and a signaling hub that influences cell survival, migration, and invasion. Its ability to connect laminin to the intermediate filament cytoskeleton through plectin and vimentin gives it a unique mechanical role in maintaining tissue integrity. Pathogens such as HPV16 exploit this complex for entry into host cells, making it a key host factor in viral infection. In cancer, upregulation of ITGA6 and the alpha6-beta4 complex promotes hepatocellular carcinoma progression, and the complex can form ternary signaling complexes with IGF1 and IGF1R to support anchorage-independent growth. Autoantibodies targeting alpha6 and beta4 integrins are associated with complement activation and blistering skin diseases, highlighting its clinical relevance.
• Maintains epithelial integrity by anchoring laminin to the intermediate filament cytoskeleton via plectin and vimentin.
• Serves as a receptor for HPV16 entry into host keratinocytes.
• Forms signaling ternary complexes with IGF1 and IGF1R to support anchorage-independent survival.
• Drives hepatocellular carcinoma progression when ITGA6 is upregulated.
• Is a target of autoantibodies in blistering skin diseases with complement activation.
• Is implicated in skin fragility syndromes affecting adhesion.
• Participates in podosome formation and Erk1/2 signaling in oral epithelial cells.
• Provides a model for studying integrin-dependent mechanotransduction and cytoskeletal coupling.
• Offers a therapeutic target for cancers with high ITGA6/ITGB4 expression.
• Enables functional genomics screens for adhesion, invasion, and pathogen entry.
Core Biology of GO:0034676
Biological Process: What Happens During integrin alpha6-beta4 complex?
In simple terms: The complex grabs laminin outside the cell and pulls on the cytoskeleton inside the cell to keep tissues stuck together and to send signals.
The integrin alpha6-beta4 complex mediates cell adhesion to laminin and organizes stable adhesion structures. It recruits plectin and vimentin to distribute adhesion complexes and support invasive growth. In oral epithelial cells, integrin signaling through Erk1/2 promotes podosome formation. The complex also participates in anchorage-independent signaling by binding IGF1 and forming a ternary complex with IGF1R. These processes collectively regulate epithelial polarity, migration, and survival.
Cellular Component: Structure and Composition of integrin alpha6-beta4 complex
In simple terms: The complex is made of two protein chains, alpha6 and beta4, that stick together on the cell surface.
The integrin alpha6-beta4 complex is a heterodimer of one ITGA6 (alpha6) subunit and one ITGB4 (beta4) subunit. The beta4 subunit has a large cytoplasmic domain that binds plectin, which in turn connects to vimentin intermediate filaments. This structural arrangement distinguishes it from actin-linked integrins and allows it to form hemidesmosome-like adhesion sites. The complex is expressed in epithelial cells and is a key component of the adhesion machinery.
Molecular Function: Molecular Mechanism of integrin alpha6-beta4 complex
In simple terms: The complex binds laminin and transmits mechanical and chemical signals into the cell.
The molecular function of the integrin alpha6-beta4 complex is laminin binding and signal transduction. It can directly bind IGF1 and form a ternary complex with IGF1R under anchorage-independent conditions, thereby activating survival signaling. The beta4 cytoplasmic tail serves as a scaffold for adaptor proteins, including plectin, which links to vimentin. This signaling axis can activate Erk1/2 and promote podosome formation. The complex also serves as a receptor for HPV16 entry, demonstrating its role in pathogen recognition.
Regulation of integrin alpha6-beta4 complex
In simple terms: The amount and activity of the complex are controlled by growth factors, autoantibodies, and cellular context.
Keratinocyte growth factor (KGF) induces podosome formation via integrin-Erk1/2 signaling in human immortalized oral epithelial cells, indicating that growth factor signaling regulates the complex's downstream effects. Autoantibodies against alpha6 and beta4 integrins can activate complement and drive pathogenicity in vivo. The complex is also regulated by its interaction with IGF1 and IGF1R, which stabilizes it under anchorage-independent conditions. These regulatory inputs modulate adhesion, migration, and survival.
Key Genes Involved in GO:0034676 integrin alpha6-beta4 complex
The following genes and proteins are directly involved in the structure, regulation, and function of the integrin alpha6-beta4 complex.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ITGA6 | Encodes the alpha6 integrin subunit of the heterodimer | Upregulated in hepatocellular carcinoma and required for complex formation |
| ITGB4 | Encodes the beta4 integrin subunit with a long cytoplasmic domain | Mediates HPV16 entry and links to intermediate filaments |
| PLEC | Plectin, adaptor that binds beta4 and vimentin | Required for adhesion complex distribution and invasive growth |
| VIM | Vimentin intermediate filament protein | Supports adhesion complex distribution with plectin |
| IGF1 | Ligand that binds alpha6-beta4 and forms ternary complex with IGF1R | Promotes anchorage-independent survival signaling |
| IGF1R | Receptor tyrosine kinase in ternary complex with alpha6-beta4 and IGF1 | Mediates cross-talk with integrin signaling |
| ERK1/2 (MAPK3/MAPK1) | Downstream kinases activated by integrin signaling | Drive podosome formation in oral epithelial cells |
| KGF (FGF7) | Growth factor that induces podosome formation via integrin-Erk1/2 | Regulates integrin-dependent adhesion structures |
| HPV16 L1 | Viral capsid protein that uses beta4 integrin for entry | Host-pathogen interaction studies |
| Complement proteins | Activated by anti-alpha6 and anti-beta4 autoantibodies | Autoimmune blistering disease mechanisms |
| BP180 (COL17A1) | Autoantigen in pemphigoid that interacts with integrin complexes | Native autoantigen complex detects pemphigoid autoantibodies |
| Laminin | Extracellular matrix ligand for alpha6-beta4 | Adhesion and signaling studies |
| Kindlin | Adaptor protein that can regulate integrin activation (generic) | Potential regulator of integrin function (generic) |
| Talin | Adaptor protein that can regulate integrin activation (generic) | Potential regulator of integrin function (generic) |
| CD151 | Tetraspanin that associates with integrins (generic) | Potential modulator of integrin trafficking (generic) |
| ITGA3 | Alpha3 integrin subunit that can pair with beta1 (generic) | Related integrin family member for comparison (generic) |
| ITGB1 | Beta1 integrin subunit that pairs with alpha6 in other complexes (generic) | Alternative alpha6 partner for comparative studies (generic) |
| LAMA3 | Laminin subunit that can bind alpha6-beta4 (generic) | Extracellular matrix ligand studies (generic) |
How Is integrin alpha6-beta4 complex Regulated?
The integrin alpha6-beta4 complex is regulated at multiple levels. Growth factor signaling, such as KGF, induces downstream Erk1/2 activation and podosome formation. Autoantibodies against alpha6 and beta4 integrins can trigger complement activation and drive pathogenicity in vivo. The complex is also stabilized by binding to IGF1 and IGF1R under anchorage-independent conditions, forming a ternary complex that supports survival signaling. Additionally, its interaction with plectin and vimentin is required for proper adhesion complex distribution and invasive growth. These regulatory mechanisms collectively control the complex's adhesive and signaling functions.
integrin alpha6-beta4 complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ITGA6 | Hepatocellular carcinoma progression | ITGA6 knockout or overexpression in liver cancer cell lines |
| ITGB4 | HPV16 infection and skin fragility | ITGB4 knockout keratinocytes for viral entry assays |
| PLEC | Adhesion complex distribution and invasive growth | PLEC knockout cells for invasion assays |
| VIM | Adhesion complex distribution | VIM knockout cells for cytoskeletal imaging |
| IGF1R | Anchorage-independent survival signaling | IGF1R knockout or point-mutation models |
Cancer Progression
Upregulation of ITGA6 and the integrin alpha6-beta4 complex drives hepatocellular carcinoma progression. The complex supports anchorage-independent growth by forming a ternary complex with IGF1 and IGF1R. It also promotes invasive growth through plectin and vimentin-dependent adhesion complex distribution. These findings position the complex as a potential therapeutic target in epithelial cancers.
Viral Infection
HPV16 infection of HaCaT cells is dependent on beta4 integrin and alpha6 integrin processing. The virus exploits the integrin alpha6-beta4 complex for host cell entry, making it a key host factor in papillomavirus infection. This interaction is a model for studying pathogen-receptor recognition.
Skin Fragility and Autoimmune Blistering Diseases
Syndromes with skin fragility can involve defects in adhesion complexes, including integrin alpha6-beta4. Autoantibodies against alpha6 and beta4 integrins are associated with complement activation and pathogenicity in vivo. Native autoantigen complexes can detect pemphigoid autoantibodies, linking integrin complexes to autoimmune blistering diseases.
From integrin alpha6-beta4 complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does ITGA6 loss affect tumor growth? | ITGA6 knockout cell line or xenograft |
| Does beta4 integrin mediate HPV16 entry? | ITGB4 knockout HaCaT cells |
| How does plectin binding to beta4 regulate adhesion? | Point mutation in ITGB4 plectin-binding domain |
| Does IGF1 binding to alpha6-beta4 promote survival? | Knock-in of IGF1-binding mutant or overexpression |
| Can autoantibodies against alpha6-beta4 activate complement? | Passive transfer mouse models or in vitro complement assays |
| What is the role of alpha6-beta4 in podosome formation? | Overexpression or knockout in oral epithelial cells |
How to Study the integrin alpha6-beta4 complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Immunofluorescence | Subcellular localization of integrin subunits and adaptors | Adhesion complex imaging |
| Co-immunoprecipitation | Protein-protein interactions within the complex | Identifying binding partners |
| Western blot | Expression and phosphorylation of signaling proteins | Erk1/2 activation assays |
| CRISPR knockout | Loss-of-function phenotypes | Testing gene requirement in adhesion or infection |
| Overexpression | Gain-of-function effects | Modeling ITGA6 upregulation in cancer |
| Point mutation | Domain-specific functions | Dissecting plectin or IGF1 binding |
| Native autoantigen complex assay | Autoantibody detection | Pemphigoid serology |
| Complement activation assay | Antibody-mediated complement deposition | Autoimmune disease modeling |
Imaging and Adhesion Assays
Immunofluorescence and live-cell imaging can visualize the distribution of integrin alpha6-beta4, plectin, and vimentin in adhesion complexes. Adhesion assays on laminin-coated surfaces measure the functional impact of genetic perturbations.
Proteomics and Co-Immunoprecipitation
Co-immunoprecipitation followed by mass spectrometry can identify components of the integrin alpha6-beta4 complex and its interacting partners, such as plectin and IGF1R. Native autoantigen complex assays can detect autoantibodies against the complex.
Signaling Assays
Phospho-Erk1/2 Western blotting and kinase inhibitor studies can assess downstream signaling activated by the complex. Ternary complex formation with IGF1 and IGF1R can be tested by cross-linking and immunoblotting.
Functional Genomics Screens
CRISPR knockout screens can identify genes required for integrin alpha6-beta4-dependent adhesion, invasion, or viral entry. Overexpression and point-mutation models can dissect domain-specific functions.
How CRISPR Can Be Used to Study GO:0034676 integrin alpha6-beta4 complex
Knockout
CRISPR knockout of ITGA6 or ITGB4 can abolish formation of the integrin alpha6-beta4 complex, enabling studies of its role in adhesion, invasion, and viral entry. Knockout of PLEC or VIM can disrupt downstream cytoskeletal linkage.
Point Mutation
Point mutations in ITGB4 can disrupt specific binding sites, such as the plectin-binding domain, to dissect domain-specific functions without losing the entire protein. Similarly, mutations in ITGA6 can affect integrin processing and HPV16 entry.
Knock-in
Knock-in of tagged ITGA6 or ITGB4 allows endogenous labeling and tracking of the complex in live cells. Knock-in of disease-associated mutations can model skin fragility syndromes.
Overexpression
Overexpression of ITGA6 or ITGB4 can drive complex formation and model cancer progression, as seen in hepatocellular carcinoma. Overexpression can also be used to study signaling cross-talk with IGF1R.
How EDITGENE Supports integrin alpha6-beta4 complex Research
Researchers studying integrin alpha6-beta4 complex-related genes often need to determine whether a candidate gene is causally involved in adhesion, signaling, or disease progression. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this discovery process, from knockout to precise point mutations and library screening.
Contact EDITGENE today to design your custom CRISPR model for integrin alpha6-beta4 complex research.
Frequently Asked Questions About integrin alpha6-beta4 complex
What is the integrin alpha6-beta4 complex?
It is a heterodimeric cell-surface receptor composed of one alpha6 (ITGA6) and one beta4 (ITGB4) subunit, defined as GO:0034676.
What genes are involved in the integrin alpha6-beta4 complex?
The core genes are ITGA6 and ITGB4, with accessory proteins such as PLEC, VIM, IGF1, and IGF1R.
What is the function of GO:0034676?
It mediates laminin binding, links to the intermediate filament cytoskeleton, and activates signaling pathways such as Erk1/2.
How is the integrin alpha6-beta4 complex linked to cancer?
Upregulation of ITGA6 and the complex drives hepatocellular carcinoma progression and supports anchorage-independent growth.
Does HPV16 use the integrin alpha6-beta4 complex for entry?
Yes, HPV16 infection of HaCaT cells is dependent on beta4 integrin and alpha6 integrin processing.
What diseases are associated with alpha6-beta4 integrin autoantibodies?
Autoantibodies against alpha6 and beta4 integrins are linked to complement activation and blistering skin diseases.
What proteins interact with the integrin alpha6-beta4 complex?
Plectin, vimentin, IGF1, and IGF1R are key interacting partners.
How can I study the integrin alpha6-beta4 complex in the lab?
Common methods include immunofluorescence, co-immunoprecipitation, CRISPR knockout, and signaling assays.
What is the role of plectin in the integrin alpha6-beta4 complex?
Plectin binds the beta4 cytoplasmic domain and links the complex to vimentin intermediate filaments, which is required for adhesion complex distribution and invasive growth.
Can CRISPR be used to model integrin alpha6-beta4 complex diseases?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to study its role in cancer, infection, and skin diseases.
Conclusion
The integrin alpha6-beta4 complex (GO:0034676) is a specialized adhesion receptor that connects laminin to the intermediate filament cytoskeleton and serves as a signaling platform in epithelial cells. Its roles in cancer progression, viral entry, and autoimmune skin diseases make it a compelling target for functional genomics and therapeutic development. Understanding its regulation and interactions through CRISPR-based models will continue to reveal new insights into epithelial biology and disease.
References
- 1. Sa G et al.. 2019. Keratinocyte growth factor (KGF) induces podosome formation via integrin-Erk1/2 signaling in human immortalized oral epithelial cells.. Cell Signal 61:39-47 PMID: 31082464
- 2. Du G et al.. 2026. Complement Activation May Drive the Pathogenicity of Anti-α6 and Anti-β4 Integrin Antibodies In Vivo.. Biomolecules 16(3) PMID: 41897353
- 3. Qi L et al.. 2022. Integrin α6β4 requires plectin and vimentin for adhesion complex distribution and invasive growth.. J Cell Sci 135(2) PMID: 34897465
- 4. Aksoy P et al.. 2014. HPV16 infection of HaCaTs is dependent on β4 integrin, and α6 integrin processing.. Virology 449:45-52 PMID: 24418536
- 5. Fujita M et al.. 2012. Cross-talk between integrin α6β4 and insulin-like growth factor-1 receptor (IGF1R) through direct α6β4 binding to IGF1 and subsequent α6β4-IGF1-IGF1R ternary complex formation in anchorage-independent conditions.. J Biol Chem 287(15):12491-500 PMID: 22351760
- 6. Reimer A et al.. 2019. [Syndromes with skin fragility].. Hautarzt 70(7):481-489 PMID: 31197392
- 7. Mai S et al.. 2023. Native Autoantigen Complex Detects Pemphigoid Autoantibodies.. JID Innov 3(3):100193 PMID: 36992950
- 8. Zheng G et al.. 2022. Integrin alpha 6 is upregulated and drives hepatocellular carcinoma progression through integrin α6β4 complex.. Int J Cancer 151(6):930-943 PMID: 35657344
