GO:0034683 integrin alphav-beta3 complex: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0034683 (integrin alphav-beta3 complex) is a heterodimeric cell-surface adhesion receptor composed of one ITGAV (alphav) subunit and one ITGB3 (beta3) subunit.
• The complex binds extracellular matrix ligands such as osteopontin and mediates bidirectional signaling that controls cell migration, invasion, and survival.
• Integrin alphav-beta3 signaling is transduced through SRC, FAK, and PI3K/AKT/mTOR pathways, making it a central node in cancer progression.
• The complex is a validated imaging and therapeutic target, with RGD-based radiotracers and humanized antibodies such as Vitaxin developed against it.
• Mechanical force transmission through alphav-beta3 requires adaptor proteins such as RPTP-alpha, linking the complex to mechanotransduction.
• CRISPR knockout, point-mutation, knock-in, and overexpression models enable causal dissection of ITGAV/ITGB3 function in disease.
Description
The integrin alphav-beta3 complex (GO:0034683) is a heterodimeric transmembrane receptor that serves as a primary adhesion and signaling interface between cells and their extracellular environment. It is formed by non-covalent association of the alphav (ITGAV) and beta3 (ITGB3) subunits and is one of the most extensively studied integrin heterodimers because of its roles in angiogenesis, tumor progression, and bone remodeling. Researchers study this complex to understand how cells sense and respond to the extracellular matrix, and to develop targeted imaging agents and therapeutics. The complex is a cellular_component term in the Gene Ontology, meaning it describes a specific molecular machine rather than a process or activity. Its functional importance derives from its ability to transmit mechanical and biochemical signals across the plasma membrane, thereby regulating cell migration, invasion, proliferation, and survival. Dysregulation of alphav-beta3 has been implicated in breast cancer metastasis, where it activates SRC/FAK/PI3K signaling and promotes invasive behavior. Because of its accessibility at the cell surface and its causal role in disease, the integrin alphav-beta3 complex is a prime target for functional genomics. CRISPR-based models that knock out, mutate, or overexpress ITGAV and ITGB3 allow researchers to test causality and to evaluate therapeutic strategies.
integrin alphav-beta3 complex At A Glance
| GO ID | GO:0034683 |
|---|---|
| GO term | integrin alphav-beta3 complex |
| Ontology | cellular_component |
| Synonym | alphav-beta3 integrin complex; ITGAV-ITGB3 complex |
| Definition | An integrin complex that comprises one alphav subunit and one beta3 subunit. |
| Major function | Cell adhesion to extracellular matrix and bidirectional signal transduction |
| Subunits | ITGAV (alphav) and ITGB3 (beta3) |
| Ligands | Osteopontin, RGD-containing matrix proteins |
| Downstream pathways | SRC, FAK, PI3K/AKT/mTOR |
What Is GO:0034683?
GO:0034683 (integrin alphav-beta3 complex) is defined as an integrin complex that comprises one alphav subunit and one beta3 subunit. In other words, it is a specific heterodimeric protein complex located at the cell membrane, formed by the non-covalent pairing of the ITGAV (alphav) and ITGB3 (beta3) integrin chains. This complex functions as a receptor for extracellular matrix proteins and as a signaling hub that connects the extracellular environment to the intracellular cytoskeleton and signaling machinery.
Why Is integrin alphav-beta3 complex Important in Cell Biology?
The integrin alphav-beta3 complex is important because it sits at the intersection of cell adhesion, mechanotransduction, and survival signaling, and its dysregulation drives cancer progression, metastasis, and other pathologies. It is also a clinically validated target: RGD-based radiotracers have been developed for imaging alphav-beta3 expression, and humanized antibodies such as Vitaxin have been affinity-matured for therapeutic targeting. Understanding its assembly, regulation, and downstream effects is therefore essential for both basic cell biology and translational research.
• Mediates cell adhesion to extracellular matrix proteins such as osteopontin.
• Transmits mechanical force across the membrane via RPTP-alpha and the cytoskeleton.
• Activates SRC/FAK/PI3K signaling to promote cell migration and invasion.
• Drives breast cancer cell movement and metastasis in response to thyroid hormone.
• Supports tumor cell survival by inactivating apoptosis and inducing autophagy.
• Serves as a target for molecular imaging with RGD-based radiotracers.
• Is targeted by humanized therapeutic antibodies such as Vitaxin.
• Functions in tissue regeneration and coagulation factor XIII biology.
• Is incorporated into functional polymeric biomaterials for cell adhesion.
• Responds to physical cues such as magnetic fields in bone scaffold applications.
Structure and Composition of integrin alphav-beta3 complex
Heterodimer assembly of ITGAV and ITGB3
In simple terms: The complex is made of two different protein chains that pair up to form a single functional receptor.
The integrin alphav-beta3 complex is a non-covalent heterodimer of one alphav (ITGAV) subunit and one beta3 (ITGB3) subunit. Each subunit is a type I transmembrane glycoprotein with a large extracellular domain, a single transmembrane helix, and a short cytoplasmic tail. The pairing is specific and is required for export of the complex to the cell surface and for ligand binding.
Ligand-binding headpiece and RGD recognition
In simple terms: The top part of the receptor recognizes a short sequence (RGD) in matrix proteins.
The extracellular headpiece of the complex binds RGD-containing ligands such as osteopontin and other matrix proteins. This recognition is the basis for RGD-based imaging agents and for the affinity maturation of Vitaxin, a humanized anti-alphav-beta3 antibody. Ligand binding triggers conformational changes that are transmitted to the cytoplasmic tails.
Cytoplasmic tail and cytoskeletal linkage
In simple terms: The bottom part of the receptor connects to the cell's internal skeleton.
The short cytoplasmic tails of ITGAV and ITGB3 interact with adaptor and signaling proteins, including RPTP-alpha, which acts as a transducer of mechanical force on alphav-beta3-integrin-cytoskeleton linkages. This linkage allows the complex to convert mechanical cues into biochemical signals and to regulate cell shape and motility.
Signaling hub for SRC, FAK, and PI3K
In simple terms: Once activated, the receptor switches on a cascade of enzymes that tell the cell to move and survive.
Engagement of the integrin alphav-beta3 complex activates SRC and FAK, which in turn stimulate PI3K/AKT/mTOR signaling. This pathway promotes cell migration, invasion, and survival, and its inactivation by osteopontin knockdown induces autophagy and apoptosis in breast cancer cells. Thyroid hormone further modulates this axis to control breast cancer cell movement.
Integration into biomaterials and scaffolds
In simple terms: The receptor can be presented on artificial surfaces to control how cells stick and grow.
Functional cell adhesion receptors including integrins have been incorporated into polymeric architectures to direct cell behavior. Magnetic field stimulation of PLLA bone scaffolds has been shown to boost transmembrane transport of magnesium ions, a process relevant to integrin-mediated bone regeneration. Coagulation factor XIII also contributes to tissue-regenerating functions that intersect with integrin biology.
Key Genes Involved in GO:0034683 integrin alphav-beta3 complex
The following genes and proteins are the principal molecular players associated with the integrin alphav-beta3 complex and its downstream signaling.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ITGAV | Encodes the alphav subunit of the heterodimer | Core component; knockout abolishes complex formation |
| ITGB3 | Encodes the beta3 subunit of the heterodimer | Core component; point mutations affect ligand binding |
| SRC | Non-receptor tyrosine kinase activated downstream | Mediates migration and invasion signals |
| PTK2 (FAK) | Focal adhesion kinase downstream of integrins | Central to adhesion turnover and motility |
| PIK3CA | Catalytic subunit of PI3K | Links integrin signaling to AKT/mTOR |
| AKT1 | Serine/threonine kinase in survival pathway | Promotes survival and inhibits apoptosis |
| MTOR | Kinase controlling growth and autophagy | Inactivated by osteopontin knockdown |
| SPP1 (Osteopontin) | Extracellular matrix ligand for alphav-beta3 | Knockdown inhibits migration and invasion |
| PTPRA (RPTP-alpha) | Transducer of mechanical force | Links integrin to cytoskeleton |
| F13A1 | Coagulation factor XIII A subunit | Tissue-regenerating functions |
| THRA/THRB | Thyroid hormone receptors | Modulate integrin-dependent breast cancer movement |
| VCL (Vinculin) | Cytoskeletal adaptor at focal adhesions | Connects integrins to actin |
| TLN1 (Talin) | Activates integrins and links to actin | Required for force transmission |
| ACTB | Actin cytoskeleton | Effector of integrin-mediated motility |
| FN1 (Fibronectin) | Extracellular matrix ligand | Supports RGD-dependent adhesion |
| VWF | Von Willebrand factor | Beta3 integrin ligand in hemostasis |
| ITGB3 variants | Polymorphisms affecting receptor function | Associated with platelet and bone phenotypes |
How Is integrin alphav-beta3 complex Regulated?
The integrin alphav-beta3 complex is regulated at multiple levels. Ligand occupancy and conformational activation control its affinity for extracellular matrix proteins. Downstream, SRC/FAK/PI3K/AKT/mTOR signaling provides feedback that modulates cell migration and survival. Mechanical force transmitted through RPTP-alpha and the cytoskeleton dynamically regulates integrin-cytoskeleton linkages. Thyroid hormone signaling also controls integrin-dependent breast cancer cell movement. In tissue regeneration contexts, factor XIII and biomaterial scaffolds influence integrin-mediated responses.
integrin alphav-beta3 complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ITGAV | Breast cancer metastasis | ITGAV knockout in MDA-MB-231 cells |
| ITGB3 | Platelet and bone disorders | ITGB3 point-mutation knock-in mice |
| SPP1 | Tumor invasion and autophagy | Osteopontin knockdown in breast cancer cells |
| PTPRA | Mechanotransduction defects | RPTP-alpha knockout fibroblasts |
| F13A1 | Tissue regeneration | Factor XIII overexpression models |
Breast cancer progression and metastasis
The integrin alphav-beta3 complex promotes breast cancer cell movement via thyroid hormone-dependent activation of SRC/FAK/PI3K signaling. Osteopontin, a ligand for the complex, induces migration and invasion while suppressing apoptosis through PI3K/AKT/mTOR inactivation and autophagy induction. These findings establish the complex as a driver of metastatic behavior in breast cancer.
Mechanotransduction and tissue remodeling
RPTP-alpha acts as a transducer of mechanical force on alphav-beta3-integrin-cytoskeleton linkages, implicating the complex in mechanosensitive processes such as bone remodeling and wound healing. Coagulation factor XIII contributes to tissue-regenerating functions that intersect with integrin biology, and magnetic field-stimulated PLLA scaffolds enhance magnesium ion transport relevant to bone regeneration.
Targeted imaging and therapy
The complex is a validated target for molecular imaging: 99mTc(CO)3-BPy-RGD has been prepared and characterized as an alphav-beta3 integrin receptor-targeted imaging agent. Vitaxin, a humanized alphav-beta3-specific monoclonal antibody, was affinity-matured in vitro for therapeutic applications. These developments highlight the translational potential of targeting this complex.
From integrin alphav-beta3 complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does ITGAV loss abolish alphav-beta3 complex formation? | ITGAV knockout cell line |
| Does a point mutation in ITGB3 alter ligand binding? | ITGB3 point-mutation knock-in |
| Can tagged ITGAV track complex localization? | Tagged knock-in of ITGAV |
| Does ITGB3 overexpression increase migration? | ITGB3 overexpression in breast cancer cells |
| Does osteopontin knockdown affect autophagy? | SPP1 knockout or knockdown |
| Does RPTP-alpha mediate force transduction? | PTPRA knockout fibroblasts |
How to Study the integrin alphav-beta3 complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss of ITGAV or ITGB3 function | Testing requirement for adhesion and migration |
| Point-mutation knock-in | Effect of specific residues on ligand binding | Modeling disease variants |
| Tagged knock-in | Complex localization and trafficking | Live-cell imaging |
| Overexpression | Gain-of-function effects on signaling | Amplifying SRC/FAK/PI3K pathways |
| Phospho-proteomics | Activation of downstream kinases | Mapping integrin signaling |
| RNA-seq | Transcriptional changes upon complex modulation | Identifying target genes |
| RGD radiotracer imaging | Cell-surface alphav-beta3 expression | In vivo tumor imaging |
| Antibody-based detection | Protein levels and localization | Validating knockout and knock-in |
CRISPR knockout and point-mutation models
CRISPR-Cas9 knockout of ITGAV or ITGB3 eliminates the integrin alphav-beta3 complex and allows assessment of its requirement for adhesion, migration, and signaling. Point mutations in ITGB3 can be introduced to dissect ligand-binding determinants and to model disease-associated variants.
Knock-in and tagged reporters
Knock-in of epitope or fluorescent tags into ITGAV or ITGB3 enables live-cell imaging of complex trafficking and localization. Tagged knock-in models are also useful for proteomic isolation of the complex and its associated proteins.
Overexpression and pathway analysis
Overexpression of ITGB3 or its ligands such as osteopontin can amplify integrin signaling and reveal downstream effects on SRC/FAK/PI3K/AKT/mTOR. Combining overexpression with phospho-proteomics or RNA-seq provides a systems-level view of the pathways controlled by the complex.
Imaging and radiotracer development
RGD-based radiotracers such as 99mTc(CO)3-BPy-RGD allow non-invasive imaging of alphav-beta3 expression. Antibody-based reagents like Vitaxin can be used for targeted delivery and for validating cell-surface expression of the complex.
How CRISPR Can Be Used to Study GO:0034683 integrin alphav-beta3 complex
Knockout
CRISPR knockout of ITGAV or ITGB3 is used to completely eliminate the integrin alphav-beta3 complex, enabling loss-of-function studies of cell adhesion, migration, and downstream SRC/FAK/PI3K signaling. Knockout models are essential for distinguishing causal roles from correlative observations.
Point Mutation
Point-mutation knock-in of specific residues in ITGB3 or ITGAV allows precise testing of ligand-binding and signaling motifs without altering protein expression levels. This approach is particularly valuable for modeling disease-associated variants and for dissecting structure-function relationships.
Knock-in
Knock-in of tags or reporter cassettes into the endogenous ITGAV or ITGB3 loci enables tracking of the complex in live cells and tissues. Tagged knock-in lines also facilitate affinity purification and proteomic identification of complex-associated proteins.
Overexpression
Overexpression of ITGB3, ITGAV, or their ligands such as osteopontin amplifies integrin signaling and can reveal gain-of-function phenotypes in migration, invasion, and survival. Overexpression models are useful for testing therapeutic interventions that target the complex.
How EDITGENE Supports integrin alphav-beta3 complex Research
Researchers studying integrin alphav-beta3 complex-related genes often need to determine whether a candidate gene is causally involved in adhesion, migration, or disease progression. EDITGENE provides publication-ready CRISPR models and bioinformatics services to accelerate this discovery process.
Contact EDITGENE today to design your custom CRISPR model for integrin alphav-beta3 complex research.
Frequently Asked Questions About integrin alphav-beta3 complex
What is the integrin alphav-beta3 complex?
It is a heterodimeric cell-surface receptor (GO:0034683) composed of one alphav (ITGAV) subunit and one beta3 (ITGB3) subunit that mediates adhesion and signaling.
What genes are involved in the integrin alphav-beta3 complex?
The core genes are ITGAV and ITGB3, with downstream effectors including SRC, PTK2 (FAK), PIK3CA, AKT1, and MTOR.
What is the function of GO:0034683?
GO:0034683 functions in cell adhesion to extracellular matrix ligands such as osteopontin and in bidirectional signal transduction that controls migration, invasion, and survival.
How is the integrin alphav-beta3 complex activated?
Ligand binding to the extracellular headpiece triggers conformational changes that are transmitted to the cytoplasmic tails, activating SRC/FAK/PI3K signaling.
What diseases are associated with integrin alphav-beta3?
It is implicated in breast cancer progression and metastasis, mechanotransduction defects, and tissue remodeling disorders.
How can I study integrin alphav-beta3 in the lab?
Common approaches include CRISPR knockout, point-mutation knock-in, tagged knock-in, overexpression, phospho-proteomics, and RGD-based imaging.
What is the role of osteopontin in alphav-beta3 signaling?
Osteopontin is a ligand for the complex; its knockdown inhibits alphav-beta3-induced migration and invasion and promotes apoptosis via PI3K/AKT/mTOR inactivation.
Is integrin alphav-beta3 a therapeutic target?
Yes, RGD-based radiotracers and humanized antibodies such as Vitaxin have been developed to target it for imaging and therapy.
What is RPTP-alpha's role in alphav-beta3 function?
RPTP-alpha acts as a transducer of mechanical force on alphav-beta3-integrin-cytoskeleton linkages.
Can CRISPR be used to model integrin alphav-beta3 diseases?
Yes, CRISPR knockout, point-mutation, knock-in, and overexpression models enable causal testing of ITGAV and ITGB3 in disease-relevant phenotypes.
Conclusion
The integrin alphav-beta3 complex (GO:0034683) is a central adhesion and signaling receptor whose dysregulation contributes to cancer progression, mechanotransduction defects, and tissue remodeling disorders. Its accessibility at the cell surface and its causal role in disease make it a prime target for imaging, therapeutic antibodies, and functional genomics. CRISPR-based models that knockout, mutate, knock in, or overexpress ITGAV and ITGB3 provide the tools needed to dissect its biology and to evaluate new interventions.
References
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- 3. Zhang H et al.. 2014. Osteopontin knockdown inhibits αv,β3 integrin-induced cell migration and invasion and promotes apoptosis of breast cancer cells by inducing autophagy and inactivating the PI3K/Akt/mTOR pathway.. Cell Physiol Biochem 33(4):991-1002 PMID: 24714122
- 4. von Wichert G et al.. 2003. RPTP-alpha acts as a transducer of mechanical force on alphav/beta3-integrin-cytoskeleton linkages.. J Cell Biol 161(1):143-53 PMID: 12682088
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- 6. Yan Z et al.. 2023. Magnetic Field Boosts the Transmembrane Transport Efficiency of Magnesium Ions from PLLA Bone Scaffold.. Small 19(40):e2301426 PMID: 37271895
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- 8. Wu H et al.. 1998. Stepwise in vitro affinity maturation of Vitaxin, an alphav beta3-specific humanized mAb.. Proc Natl Acad Sci U S A 95(11):6037-42 PMID: 9600913
