GO:0038143 ERBB3:ERBB2 complex: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0038143 describes the heterodimeric complex formed between the ligand-activated receptor ERBB3 and the kinase-active receptor ERBB2.
• ERBB2 lacks a known ligand and is activated by heterodimerization with ligand-bound ERBB3, making this complex a central signaling unit.
• The ERBB3:ERBB2 complex is a potent oncogenic driver in melanoma, breast cancer, and other malignancies.
• ERBB3 pseudokinase mutations can trans-activate ERBB2 and promote tumorigenesis.
• This complex is also implicated in nervous system biology, including mechanical hypersensitivity after nerve injury.
• Research on this complex uses knockout, point-mutation, knock-in, and overexpression models to dissect its signaling and therapeutic potential.
Description
The ERBB3:ERBB2 complex (GO:0038143) is a heterodimeric cell-surface receptor assembly that forms when the ligand-activated tyrosine kinase receptor ERBB3 binds to ERBB2, a receptor that does not bind any known ligand. This complex is a critical signaling node because ERBB2 provides the catalytic kinase activity that ERBB3 lacks, while ERBB3 provides ligand-binding specificity and docking sites for downstream effectors. The complex is activated by neuregulin ligands such as NRG1 and NRG2, which induce ERBB3 phosphorylation and subsequent heterodimerization with ERBB2. Researchers study GO:0038143 because it represents a paradigm of ligand-dependent activation of a pseudokinase receptor through heterodimerization, and because its dysregulation is linked to cancer, nervous system disorders, and therapeutic resistance.
ERBB3:ERBB2 complex At A Glance
| GO ID | GO:0038143 |
|---|---|
| GO term | ERBB3:ERBB2 complex |
| Ontology | cellular_component |
| Synonym | EGFR:ERBB2 heterodimer; NRG1/2:ERBB3:ERBB2 |
| Major function | Ligand-induced heterodimeric receptor complex that activates downstream signaling, including PI3K/AKT and MAPK pathways |
| Complex members | ERBB3 (ligand-binding pseudokinase) and ERBB2 (kinase-active receptor) |
| Ligands | Neuregulin 1 (NRG1) and neuregulin 2 (NRG2) |
| Associated diseases | Melanoma, breast cancer, trigeminal neuralgia, and other cancers |
| Research models | Knockout, point-mutation, knock-in, and overexpression cell models |
What Is GO:0038143?
GO:0038143 is defined as a heterodimeric complex between the tyrosine kinase receptor ERBB2 and a ligand-activated receptor ERBB3. ERBB2, which does not bind any known ligand, is activated through formation of a heterodimer with another ligand-activated ERBB family member such as ERBB3. In this complex, ERBB3 binds neuregulin ligands, undergoes phosphorylation, and recruits ERBB2, which then activates downstream signaling pathways.
Why Is ERBB3:ERBB2 complex Important in Cell Biology?
The ERBB3:ERBB2 complex is important because it is a central signaling hub that drives cell proliferation, survival, and migration in both normal and pathological contexts. Its dysregulation contributes to cancer progression, therapeutic resistance, and nervous system disorders, making it a prime target for drug development and functional genomics studies.
• Acts as a potent oncogenic unit in melanoma and breast cancer.
• Mediates resistance to HER2-targeted therapies such as trastuzumab.
• Involved in neuregulin signaling that promotes tumor cell growth and survival.
• Plays a role in mechanical hypersensitivity after nerve injury.
• Implicated in trigeminal neuralgia and neuropathic pain mechanisms.
• Serves as a model for pseudokinase-mediated activation of kinase receptors.
• Provides a target for therapeutic intervention in wild-type BRAF/NRAS melanomas.
• Used in CRISPR screens to identify synthetic lethal interactions.
• Enables study of heterodimerization specificity among ERBB family members.
• Facilitates development of patient-derived models for precision oncology.
Structure and Composition of ERBB3:ERBB2 complex
ERBB3: The Ligand-Binding Pseudokinase
In simple terms: ERBB3 is the receptor that grabs the signal molecule but cannot send the message by itself.
ERBB3 is a member of the EGFR family that binds neuregulin ligands but lacks intrinsic kinase activity due to substitutions in its kinase domain. Ligand binding induces conformational changes that expose a dimerization arm, allowing ERBB3 to pair with ERBB2. The intracellular domain of ERBB3 contains multiple tyrosine phosphorylation sites that serve as docking sites for PI3K and other signaling proteins.
ERBB2: The Kinase-Active Partner
In simple terms: ERBB2 is the receptor that provides the enzymatic power to transmit the signal.
ERBB2 (also known as HER2/NEU) is a tyrosine kinase receptor that does not bind any known ligand but has constitutive kinase activity when dimerized. Its extracellular domain adopts a fixed active conformation that favors heterodimerization with ligand-bound ERBB3. Upon heterodimerization, ERBB2 phosphorylates ERBB3 and initiates downstream signaling cascades.
Heterodimer Assembly and Stoichiometry
In simple terms: The two receptors come together in a specific pair to form a functional signaling unit.
The ERBB3:ERBB2 heterodimer assembles in a 1:1 stoichiometry upon neuregulin binding to ERBB3. Biophysical studies show that homo- and heteroassociations drive ERBB3 activation, with the ERBB3:ERBB2 pair being the most signaling-competent. The complex is stabilized by interactions between the extracellular domains and the transmembrane regions.
Post-Translational Modifications and Trafficking
In simple terms: After assembly, the complex gets chemical tags that control its activity and location.
ERBB3 is heavily phosphorylated on multiple tyrosine residues within the complex, creating binding sites for adaptor proteins such as GRB2 and p85. The complex undergoes endocytosis and trafficking, which can either terminate signaling or promote sustained activation. Glycosylation and ubiquitination also regulate the stability and localization of the complex.
Key Genes Involved in GO:0038143 ERBB3:ERBB2 complex
The following genes and proteins are central to the formation, regulation, and function of the ERBB3:ERBB2 complex.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ERBB3 | Ligand-binding pseudokinase receptor; binds NRG1/2 and recruits ERBB2 | Mutations in ERBB3 can trans-activate ERBB2 and drive oncogenesis |
| ERBB2 | Kinase-active receptor; phosphorylates ERBB3 and initiates signaling | Amplified or overexpressed in breast cancer and other malignancies |
| NRG1 | Neuregulin ligand that binds ERBB3 and induces heterodimerization | Key activator of the complex in melanoma and breast cancer |
| NRG2 | Neuregulin ligand that binds ERBB3 | Alternative ligand for ERBB3:ERBB2 complex activation |
| PIK3CA | Encodes p110α subunit of PI3K; downstream effector of ERBB3:ERBB2 | Mutations confer resistance to HER2-targeted therapies |
| AKT1 | Serine/threonine kinase downstream of PI3K | Mediates survival signaling from the complex |
| MAPK1 | Extracellular signal-regulated kinase 2; downstream of RAS | Drives proliferation signals from the complex |
| MAPK3 | Extracellular signal-regulated kinase 1; downstream of RAS | Drives proliferation signals from the complex |
| GRB2 | Adaptor protein that binds phosphorylated ERBB3 | Links the complex to RAS/MAPK pathway |
| PIK3R1 | Regulatory subunit of PI3K; binds ERBB3 phosphotyrosines | Mediates PI3K/AKT activation |
| SRC | Non-receptor tyrosine kinase that can associate with the complex | Modulates signaling and resistance |
| PTEN | Lipid phosphatase that opposes PI3K signaling | Loss enhances ERBB3:ERBB2-driven tumorigenesis |
| EGFR | Related receptor that can heterodimerize with ERBB2 | Alternative dimerization partner affecting signaling specificity |
| ERBB4 | Related receptor that can heterodimerize with ERBB2 | Alternative dimerization partner affecting signaling specificity |
| IGF1R | Insulin-like growth factor 1 receptor; can form heterotrimers with ERBB2/ERBB3 | Implicated in trastuzumab resistance |
| NRG1 | Neuregulin 1; ligand for ERBB3 | Drives oncogenic signaling in melanoma |
| ERBB3 | Pseudokinase domain mutations | Trans-activating mutations promote tumorigenesis |
How Is ERBB3:ERBB2 complex Regulated?
The ERBB3:ERBB2 complex is regulated at multiple levels. Ligand availability (NRG1/2) controls the initial activation step. Phosphorylation of ERBB3 by ERBB2 is counterbalanced by phosphatases such as PTEN and PTPN12. Endocytosis and degradation of the complex modulate signal duration. Additionally, trans-activating mutations in the ERBB3 pseudokinase domain can promote ligand-independent activation of ERBB2. Downstream feedback loops involving mTOR and SHP2 also fine-tune signaling output.
ERBB3:ERBB2 complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ERBB3 | Melanoma, breast cancer | ERBB3 knockout melanoma cell lines |
| ERBB2 | Breast cancer, therapeutic resistance | ERBB2 overexpression in breast cancer cells |
| NRG1 | Melanoma, neuropathic pain | NRG1 knock-in or overexpression models |
| ERBB3 | Trigeminal neuralgia | Nerve injury models with ERBB3 point mutations |
| IGF1R | Trastuzumab resistance | IGF1R/ERBB2/ERBB3 heterotrimer knockout models |
ERBB3:ERBB2 complex in Melanoma
In cutaneous melanomas with wild-type BRAF and NRAS, ERBB3:ERBB2 complexes act as a therapeutic target. NRG1 signaling through this complex promotes melanoma cell growth and survival, and targeting the complex reduces tumor burden in preclinical models. Trans-activating mutations in ERBB3 can also drive melanoma progression by enhancing ERBB2 activation.
ERBB3:ERBB2 complex in Breast Cancer and Therapeutic Resistance
The ERBB3:ERBB2 complex is a key mediator of resistance to HER2-targeted therapies such as trastuzumab. Heterotrimerization of ERBB2, ERBB3, and IGF1R in breast cancer cells resistant to herceptin sustains PI3K/AKT signaling. Paclitaxel resistance in breast cancer has also been linked to ERBB3:ERBB2 signaling. Targeting this complex may overcome resistance in HER2-positive breast cancers.
ERBB3:ERBB2 complex in Nervous System Disorders
ERBB3:ERBB2 signaling is implicated in mechanical hypersensitivity after trigeminal nerve injury. Blocking this complex reduces pain behaviors in animal models. Systematic reviews highlight the role of ERBB3:ERBB2 in trigeminal neuralgia mechanisms, suggesting potential for therapeutic intervention.
From ERBB3:ERBB2 complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does ERBB3 kinase activity contribute to complex signaling? | ERBB3 point-mutation (kinase-dead) knock-in |
| What is the role of ERBB2 kinase domain in the complex? | ERBB2 knockout or kinase-dead point mutation |
| How does NRG1 ligand availability affect complex formation? | NRG1 overexpression or knockout |
| Can targeting the complex overcome drug resistance? | ERBB3:ERBB2 complex knockout in resistant breast cancer cells |
| What are the downstream effectors of the complex? | Tagged knock-in of ERBB3 for proteomics |
| Does the complex drive melanoma growth in vivo? | ERBB3 knockout melanoma xenografts |
How to Study the ERBB3:ERBB2 complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Co-immunoprecipitation | Physical interaction between ERBB3 and ERBB2 | Confirm complex formation in cells |
| Phosphoproteomics | Tyrosine phosphorylation sites on complex members | Map signaling activation |
| FRET/BiFC | Real-time heterodimerization | Visualize complex assembly |
| CRISPR knockout screening | Genes required for complex-driven growth | Identify therapeutic targets |
| RNA-seq | Transcriptional changes downstream of complex | Profile gene expression |
| Proximity ligation assay | In situ detection of ERBB3:ERBB2 complexes | Tissue localization |
| Surface plasmon resonance | Binding affinity between ERBB3 and ERBB2 | Biophysical characterization |
Proteomic Analysis of the ERBB3:ERBB2 Complex
Affinity purification coupled with mass spectrometry (AP-MS) can identify proteins that associate with the ERBB3:ERBB2 complex. Tagged knock-in of ERBB3 or ERBB2 allows endogenous complex isolation and detection of post-translational modifications. This approach reveals dynamic changes in complex composition upon ligand stimulation.
Phosphoproteomics and Signaling Profiling
Phosphoproteomics quantifies tyrosine phosphorylation sites on ERBB3 and ERBB2, providing a snapshot of complex activation. This method identifies downstream signaling nodes such as PI3K/AKT and MAPK. It is useful for comparing wild-type and mutant complexes.
Live-Cell Imaging of Heterodimerization
Fluorescence resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) can visualize ERBB3:ERBB2 heterodimerization in live cells. These techniques reveal the spatiotemporal dynamics of complex assembly and trafficking.
CRISPR Library Screening for Modifiers
Genome-wide CRISPR knockout or activation screens can identify genes that regulate ERBB3:ERBB2 complex signaling. Such screens have uncovered synthetic lethal interactions and resistance mechanisms. Bioinformatics analysis of screen data prioritizes candidate pathways for validation.
How CRISPR Can Be Used to Study GO:0038143 ERBB3:ERBB2 complex
Knockout
CRISPR knockout of ERBB3 or ERBB2 abolishes formation of the ERBB3:ERBB2 complex, enabling loss-of-function studies. Knockout cell models have been used to demonstrate the requirement for the complex in melanoma growth and breast cancer resistance. These models are essential for validating on-target effects of therapeutic antibodies.
Point Mutation
Point mutations in the ERBB3 pseudokinase domain can trans-activate ERBB2, mimicking oncogenic mutations found in patients. CRISPR-mediated knock-in of such mutations allows study of ligand-independent activation and drug sensitivity. Kinase-dead mutations in ERBB2 can dissect the contribution of its catalytic activity.
Knock-in
Knock-in of epitope tags (e.g., HA, FLAG) into endogenous ERBB3 or ERBB2 loci facilitates affinity purification and proteomic analysis of the complex. Knock-in of fluorescent proteins enables live-cell imaging of heterodimerization. These models preserve endogenous expression levels and regulation.
Overexpression
Overexpression of ERBB3 and ERBB2 in cell lines drives constitutive complex formation and downstream signaling, modeling oncogenic amplification. Overexpression models are useful for testing targeted inhibitors and resistance mechanisms. They can also be combined with CRISPR screens to identify modifiers.
How EDITGENE Supports ERBB3:ERBB2 complex Research
Researchers studying ERBB3:ERBB2 complex-related genes often need to determine whether a candidate gene is causally involved in complex assembly, signaling, or disease. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models for such functional studies.
Contact EDITGENE today to design your custom CRISPR model for ERBB3:ERBB2 complex research.
Frequently Asked Questions About ERBB3:ERBB2 complex
What is the ERBB3:ERBB2 complex?
The ERBB3:ERBB2 complex (GO:0038143) is a heterodimeric receptor assembly formed when ligand-activated ERBB3 binds to ERBB2, enabling downstream signaling.
What genes are involved in the ERBB3:ERBB2 complex?
The core genes are ERBB3 and ERBB2, with ligands NRG1 and NRG2, and downstream effectors such as PIK3CA, AKT1, and MAPK1.
How is the ERBB3:ERBB2 complex activated?
Neuregulin ligands bind ERBB3, inducing a conformational change that promotes heterodimerization with ERBB2, which then phosphorylates ERBB3 and initiates signaling.
What diseases are associated with the ERBB3:ERBB2 complex?
It is implicated in melanoma, breast cancer, therapeutic resistance, and neuropathic pain conditions such as trigeminal neuralgia.
Why is ERBB2 important in the complex?
ERBB2 provides the kinase activity that ERBB3 lacks, making it essential for signal transduction.
Can the ERBB3:ERBB2 complex be targeted therapeutically?
Yes, antibodies and small molecules targeting this complex are under investigation for melanoma and breast cancer.
What research models are used to study the ERBB3:ERBB2 complex?
Knockout, point-mutation, knock-in, and overexpression cell models, as well as CRISPR screens, are commonly used.
How does the ERBB3:ERBB2 complex contribute to drug resistance?
It sustains PI3K/AKT signaling in the presence of HER2-targeted therapies, leading to resistance.
What is the role of ERBB3 pseudokinase mutations?
Trans-activating mutations in ERBB3 can promote ligand-independent activation of ERBB2 and drive tumorigenesis.
How can CRISPR help study the ERBB3:ERBB2 complex?
CRISPR enables precise knockout, knock-in, and point mutations to dissect the function of complex components in disease models.
Conclusion
The ERBB3:ERBB2 complex (GO:0038143) is a critical signaling unit that integrates ligand-dependent activation of the pseudokinase ERBB3 with the catalytic activity of ERBB2. Its dysregulation drives cancer progression, therapeutic resistance, and nervous system disorders, making it a high-priority target for functional genomics and drug discovery. Advances in CRISPR-based models and proteomic methods continue to unravel the complex biology of this heterodimer, offering new opportunities for precision medicine.
References
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- 3. Ma F et al.. 2012. Trigeminal nerve injury ErbB3/ErbB2 promotes mechanical hypersensitivity.. Anesthesiology 117(2):381-8 PMID: 22705569
- 4. Váradi T et al.. 2019. Homo- and Heteroassociations Drive Activation of ErbB3.. Biophys J 117(10):1935-1947 PMID: 31653451
- 5. Dan VM et al.. 2021. Resistance to Intervention: Paclitaxel in Breast Cancer.. Mini Rev Med Chem 21(10):1237-1268 PMID: 33319669
- 6. Zhang K et al.. 2013. An ERBB3/ERBB2 oncogenic unit plays a key role in NRG1 signaling and melanoma cell growth and survival.. Pigment Cell Melanoma Res 26(3):408-14 PMID: 23480537
- 7. Smith CA et al.. 2021. Molecular mechanisms of trigeminal neuralgia: A systematic review.. Clin Neurol Neurosurg 200:106397 PMID: 33338828
- 8. Huang X et al.. 2010. Heterotrimerization of the growth factor receptors erbB2, erbB3, and insulin-like growth factor-i receptor in breast cancer cells resistant to herceptin.. Cancer Res 70(3):1204-14 PMID: 20103628
