GO:0045323 interleukin-1 receptor complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0045323 (interleukin-1 receptor complex) is a plasma membrane protein complex that binds interleukin-1 cytokines and comprises an alpha and a beta subunit.
• The canonical IL-1 receptor complex is formed by IL-1R1 (alpha subunit) and IL-1RAP (beta subunit), which together recruit MyD88 and initiate NF-kB and MAPK signaling [1,5].
• The IL-1 receptor family includes IL-1R1, IL-1R2, IL-1RAP, ST2 (IL-1RL1), and IL-18R1, with shared TIR domain signaling architecture.
• Dysregulated interleukin-1 receptor complex signaling is implicated in autoinflammatory diseases, cancer, and kidney disease [1,3,4].
• IL-1RAP is a promising immunotherapy target in human malignancies, and IL-1R2 acts as a decoy receptor in kidney disease [3,4].
• CRISPR knockout, point mutation, knock-in, and overexpression models enable causal dissection of interleukin-1 receptor complex components in disease.
Description
The interleukin-1 receptor complex (GO:0045323) is a cell-surface protein complex defined by its ability to bind interleukin-1 cytokines and by its composition of an alpha and a beta subunit. This complex is the primary signaling hub for the IL-1 family of cytokines, which includes IL-1alpha, IL-1beta, IL-33, and IL-18, and it plays a central role in innate immunity and inflammation [1,2]. The interleukin-1 receptor family comprises several related proteins, including IL-1R1, IL-1R2, IL-1RAP, ST2 (also known as IL-1RL1), and IL-18R1, all of which share a conserved Toll/interleukin-1 receptor (TIR) domain that mediates downstream signaling. Researchers study GO:0045323 because it is a nodal point in inflammatory signaling, and its dysregulation is linked to autoinflammatory diseases, cancer progression, and kidney pathology [1,3,4]. Understanding the assembly, regulation, and function of the interleukin-1 receptor complex is essential for developing targeted therapeutics, including monoclonal antibodies and small-molecule inhibitors [1,3].
interleukin-1 receptor complex At A Glance
| GO ID | GO:0045323 |
|---|---|
| GO term | interleukin-1 receptor complex |
| Ontology | cellular_component |
| Synonym | IL-1 receptor complex |
| Definition | A protein complex that binds interleukin-1; comprises an alpha and a beta subunit. |
| Major function | Binds interleukin-1 cytokines and initiates intracellular signaling via TIR domain-containing adaptors. |
| Subunits | Alpha subunit (e.g., IL-1R1) and beta subunit (e.g., IL-1RAP). |
| Related family members | IL-1R2, ST2/IL-1RL1, IL-18R1, and other IL-1 receptor family proteins. |
| Signaling pathway | MyD88-dependent NF-kB and MAPK activation. |
What Is GO:0045323?
According to the Gene Ontology, GO:0045323 (interleukin-1 receptor complex) is a protein complex that binds interleukin-1; it comprises an alpha and a beta subunit. In practice, this refers to the heteromeric receptor assembly, typically IL-1R1 (alpha) and IL-1RAP (beta), which together form a functional signaling unit upon ligand binding [1,5].
Why Is interleukin-1 receptor complex Important in Cell Biology?
The interleukin-1 receptor complex is critically important because it serves as the primary gateway for interleukin-1 family cytokine signaling, which controls fever, acute-phase response, and immune cell activation [1,6]. Dysregulation of this complex contributes to a wide range of human diseases, including autoinflammatory syndromes, rheumatoid arthritis, atherosclerosis, cancer, and kidney disease [1,3,4]. Moreover, components of the complex, such as IL-1RAP, are being actively pursued as therapeutic targets in oncology and immunotherapy. Therefore, understanding the molecular architecture and regulation of GO:0045323 is essential for both basic immunology and translational medicine.
• Central mediator of innate immune and inflammatory responses to infection and tissue damage.
• Binds multiple IL-1 family cytokines, including IL-1alpha, IL-1beta, and IL-33, integrating diverse inflammatory signals [1,2].
• Dysregulated signaling is linked to autoinflammatory diseases, cancer, and kidney disease [1,3,4].
• IL-1RAP (beta subunit) is a promising target for immunotherapy in human malignancies.
• IL-1R2 acts as a decoy receptor and is implicated in kidney disease pathogenesis.
• The complex recruits MyD88, a key adaptor whose mutations drive oncogenic NF-kB activation in lymphoma.
• Provides a model for understanding TIR domain signaling shared across Toll-like and IL-1 receptor families.
• Enables development of biologics (e.g., anakinra, canakinumab) that block IL-1 signaling.
• Serves as a research tool for studying receptor assembly, ligand specificity, and signal transduction.
• Offers opportunities for CRISPR-based functional genomics to identify therapeutic targets.
What Happens During interleukin-1 receptor complex?
Ligand binding and receptor assembly
In simple terms: First, the cytokine grabs onto the receptor, and then a second receptor subunit joins to form the active complex.
The interleukin-1 receptor complex is activated when an IL-1 family cytokine, such as IL-1beta, binds to the alpha subunit (IL-1R1) on the cell surface. This initial binding recruits the beta subunit (IL-1RAP), forming a heterodimeric complex that is stabilized by the ligand [1,5]. The assembly of this ternary complex is a prerequisite for downstream signaling and is tightly regulated by the availability of both subunits.
TIR domain engagement and adaptor recruitment
In simple terms: Once the two receptor subunits come together, their intracellular tails attract an adaptor protein called MyD88.
Both the alpha and beta subunits of the interleukin-1 receptor complex contain intracellular Toll/interleukin-1 receptor (TIR) domains. Upon ligand-induced heterodimerization, these TIR domains serve as docking sites for the TIR domain-containing adaptor protein MyD88 [1,5]. MyD88 recruitment is a critical step that links the receptor complex to downstream kinases.
NF-kB and MAPK pathway activation
In simple terms: The adaptor protein then triggers a chain reaction that turns on inflammatory genes.
MyD88 recruitment leads to the assembly of a signaling complex that activates IRAK kinases and TRAF6, ultimately resulting in the activation of NF-kB and MAPK pathways [1,8]. This signaling cascade induces the expression of pro-inflammatory cytokines, chemokines, and adhesion molecules, amplifying the inflammatory response. The importance of this pathway is underscored by the finding that oncogenically active MYD88 mutations drive NF-kB activation in human lymphoma.
Negative regulation and decoy receptors
In simple terms: The body also makes decoy receptors that soak up the cytokine and shut down the signal.
The interleukin-1 receptor complex is negatively regulated by decoy receptors such as IL-1R2, which binds IL-1 but lacks a functional TIR domain and therefore cannot signal [4,5]. IL-1R2 can exist in membrane-bound and soluble forms, acting as a sink for IL-1 and preventing receptor activation. This negative regulation is crucial for limiting excessive inflammation and is implicated in kidney disease.
Key Genes Involved in GO:0045323 interleukin-1 receptor complex
The following genes encode the core subunits, adaptors, and regulatory proteins of the interleukin-1 receptor complex and its signaling pathway.
| Gene | Major Role | Research Relevance |
|---|---|---|
| IL1R1 | Alpha subunit of the interleukin-1 receptor complex; binds IL-1alpha and IL-1beta | Primary receptor for IL-1 signaling; knockout models used to study inflammation |
| IL1RAP | Beta subunit of the complex; essential for signal transduction | Target for immunotherapy in malignancies; knockout blocks IL-1 signaling |
| IL1R2 | Decoy receptor; binds IL-1 without signaling | Implicated in kidney disease; regulates IL-1 availability |
| IL1RL1 | Encodes ST2, receptor for IL-33; forms complex with IL-1RAP | Studied in Th2 immunity and allergic inflammation |
| IL18R1 | Receptor for IL-18; forms complex with IL-18RAP | Involved in Th1 responses and autoimmunity |
| MYD88 | Adaptor protein recruited to TIR domains; activates NF-kB | Oncogenic mutations in lymphoma; central to IL-1 signaling |
| IRAK1 | Kinase recruited by MyD88; activates NF-kB | Key signaling node downstream of the receptor complex |
| IRAK4 | Kinase essential for MyD88-dependent signaling | Therapeutic target in inflammatory diseases |
| TRAF6 | E3 ubiquitin ligase; activates NF-kB and MAPK | Critical for IL-1-induced signaling |
| NFKB1 | Transcription factor subunit; drives inflammatory gene expression | Readout of IL-1 receptor complex activation |
| MAPK1 | Kinase in MAPK pathway; activated downstream of the complex | Mediates cellular responses to IL-1 |
| IL1B | Ligand for the receptor complex; pro-inflammatory cytokine | Central to fever and acute-phase response |
| IL1A | Ligand for the receptor complex; pro-inflammatory cytokine | Involved in skin and mucosal immunity |
| IL33 | Cytokine that signals via ST2/IL-1RAP complex | Drives Th2-associated cytokines |
| IL18 | Cytokine that signals via IL-18R1/IL-18RAP complex | Induces IFN-gamma production |
| TOLLIP | Regulatory protein that interacts with TIR domains | Modulates IL-1 receptor signaling |
| SIGIRR | Negative regulator of IL-1 receptor signaling | Inhibits IL-1 and TLR pathways |
| IRAK3 | Inhibitory kinase that dampens IL-1 signaling | Feedback regulation of the complex |
How Is interleukin-1 receptor complex Regulated?
The interleukin-1 receptor complex is regulated at multiple levels. Ligand availability is controlled by decoy receptors such as IL-1R2 and soluble IL-1RAP, which sequester cytokines and prevent receptor activation [4,5]. Intracellularly, signaling is negatively regulated by inhibitory proteins including SIGIRR, IRAK3, and TOLLIP, which interfere with TIR domain interactions or promote degradation of signaling intermediates. Additionally, post-translational modifications and ubiquitination of receptor subunits and adaptors fine-tune the strength and duration of the signal. Dysregulation of these control mechanisms can lead to chronic inflammation and disease [1,3].
interleukin-1 receptor complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| IL1RAP | Cancer (multiple malignancies); immunotherapy target | Knockout or knockdown in cancer cell lines; xenograft models |
| MYD88 | Diffuse large B-cell lymphoma; oncogenic NF-kB activation | Point mutation (L265P) knock-in in B cells; lymphoma models |
| IL1R2 | Kidney disease; decoy receptor regulation | Knockout mice; renal injury models |
| IL1R1 | Autoinflammatory diseases; IL-1 signaling | Knockout mice; inflammation challenge models |
| IL1RL1 | Allergic inflammation; Th2 responses | Knockout mice; asthma models |
Interleukin-1 receptor complex in cancer
Components of the interleukin-1 receptor complex are frequently dysregulated in human malignancies. IL-1RAP (beta subunit) is overexpressed in several cancers and promotes tumor cell proliferation, survival, and metastasis, making it a promising target for immunotherapy. Oncogenic mutations in MYD88, the adaptor recruited by the complex, drive constitutive NF-kB activation in diffuse large B-cell lymphoma. Targeting the IL-1 receptor complex or its downstream effectors is therefore an active area of cancer therapeutic development [3,8].
Interleukin-1 receptor complex in kidney disease
The interleukin-1 receptor complex and its regulatory components play significant roles in kidney disease. IL-1R2, a decoy receptor for IL-1, is implicated in the pathogenesis of various kidney disorders, where it modulates inflammatory injury. Dysregulated IL-1 signaling contributes to glomerulonephritis, diabetic nephropathy, and ischemia-reperfusion injury. Understanding how the receptor complex is regulated in renal tissue may lead to new therapeutic strategies.
Interleukin-1 receptor complex in autoinflammatory and inflammatory diseases
The interleukin-1 receptor complex is central to autoinflammatory diseases such as cryopyrin-associated periodic syndromes (CAPS), which are driven by excessive IL-1beta production. Blocking IL-1 signaling with recombinant IL-1RA (anakinra) or anti-IL-1beta antibodies (canakinumab) is an effective treatment for these conditions. The complex also contributes to rheumatoid arthritis, atherosclerosis, and gout, where IL-1-mediated inflammation exacerbates tissue damage [1,6].
From interleukin-1 receptor complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of IL1RAP abolish IL-1 signaling? | CRISPR knockout of IL1RAP in cell lines |
| Does the MYD88 L265P mutation drive oncogenic NF-kB? | Point mutation knock-in of MYD88 L265P |
| Can a tagged IL-1R1 be used to track receptor trafficking? | Knock-in of fluorescent or epitope tag at IL1R1 locus |
| Does overexpression of IL-1R2 reduce inflammation? | Overexpression of IL1R2 in transgenic models |
| What is the role of ST2 in Th2 cytokine production? | Knockout of IL1RL1 in mice |
| Can CRISPR screening identify regulators of IL-1 signaling? | Genome-wide CRISPR library screening in reporter cells |
How to Study the interleukin-1 receptor complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss of gene function | Test requirement for IL1RAP in IL-1 signaling |
| CRISPR point mutation | Specific nucleotide change | Model MYD88 L265P oncogenic mutation |
| Co-immunoprecipitation | Protein-protein interactions | Identify TIR domain adaptors |
| RNA-seq | Transcriptional changes | Measure NF-kB target gene expression |
| NF-kB reporter assay | Pathway activation | Screen for regulators of IL-1 signaling |
| Flow cytometry | Cell-surface receptor levels | Quantify IL-1R1 and IL-1RAP expression |
| Surface plasmon resonance | Ligand-receptor binding affinity | Characterize IL-1beta binding to IL-1R1 |
| Phospho-immunoblot | Kinase activation | Detect MAPK and NF-kB phosphorylation |
CRISPR-based functional genomics
CRISPR knockout and knock-in technologies enable precise dissection of interleukin-1 receptor complex components. Genome-wide CRISPR screens can identify genes that regulate IL-1-induced NF-kB activation, as demonstrated by the discovery of oncogenic MYD88 mutations. Point mutations can be introduced to model disease-associated variants, such as MYD88 L265P.
Biochemical and proteomic approaches
Co-immunoprecipitation and mass spectrometry can identify interacting partners of the interleukin-1 receptor complex, including adaptors and regulatory proteins. Surface plasmon resonance and isothermal titration calorimetry measure ligand binding affinities for the alpha and beta subunits.
Transcriptomic and signaling assays
RNA-seq and NF-kB reporter assays quantify downstream transcriptional responses following IL-1 stimulation. Phospho-specific antibodies against MAPK and NF-kB components measure pathway activation.
Imaging and flow cytometry
Fluorescence microscopy and flow cytometry can visualize receptor assembly, internalization, and cell-surface expression of IL-1R1 and IL-1RAP. Tagged knock-in models allow real-time tracking of receptor dynamics.
How CRISPR Can Be Used to Study GO:0045323 interleukin-1 receptor complex
Knockout
CRISPR knockout of IL1RAP or IL1R1 completely abolishes interleukin-1 receptor complex signaling, providing a clean genetic model to study loss of function. Knockout cell lines are valuable for confirming the specificity of IL-1 responses and for identifying compensatory pathways.
Point Mutation
Point mutation knock-in of disease-associated variants, such as MYD88 L265P, recapitulates oncogenic NF-kB activation observed in lymphoma. This approach allows precise modeling of how single amino acid changes alter receptor complex signaling.
Knock-in
Knock-in of epitope tags or fluorescent proteins at the IL1R1 or IL1RAP loci enables real-time tracking of receptor expression, localization, and assembly in live cells. Tagged knock-in models are also useful for proteomic pull-down experiments.
Overexpression
Overexpression of IL1R2 or other regulatory components can be used to study decoy receptor function and negative regulation of the interleukin-1 receptor complex. Overexpression models help determine whether increased receptor levels are sufficient to drive inflammatory phenotypes.
How EDITGENE Supports interleukin-1 receptor complex Research
Researchers studying interleukin-1 receptor complex-related genes often need to determine whether a candidate gene is causally involved in receptor assembly, signaling, or disease pathogenesis. 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 interleukin-1 receptor complex research.
Frequently Asked Questions About interleukin-1 receptor complex
What is the interleukin-1 receptor complex?
The interleukin-1 receptor complex (GO:0045323) is a protein complex that binds interleukin-1 and comprises an alpha and a beta subunit, typically IL-1R1 and IL-1RAP.
What genes are involved in the interleukin-1 receptor complex?
Key genes include IL1R1 (alpha subunit), IL1RAP (beta subunit), IL1R2 (decoy receptor), MYD88 (adaptor), and downstream signaling components like IRAK1, IRAK4, and TRAF6 [1,3,4,8].
What is the function of GO:0045323?
GO:0045323 functions to bind interleukin-1 cytokines and initiate intracellular signaling via TIR domain-containing adaptors, leading to NF-kB and MAPK activation [1,5].
How is the interleukin-1 receptor complex activated?
It is activated when an IL-1 family cytokine binds the alpha subunit, recruiting the beta subunit to form a heterodimer that recruits MyD88 and triggers downstream signaling [1,5].
What diseases are associated with the interleukin-1 receptor complex?
Dysregulated signaling is linked to autoinflammatory diseases, cancer, kidney disease, and inflammatory conditions like rheumatoid arthritis [1,3,4].
What is IL-1RAP and why is it important?
IL-1RAP is the beta subunit of the interleukin-1 receptor complex and is essential for signal transduction; it is a promising immunotherapy target in human malignancies.
What is the role of IL-1R2 in kidney disease?
IL-1R2 acts as a decoy receptor that binds IL-1 without signaling, and its dysregulation is implicated in kidney disease pathogenesis.
How can CRISPR be used to study the interleukin-1 receptor complex?
CRISPR knockout, point mutation, knock-in, and overexpression models allow researchers to dissect the causal roles of receptor subunits and adaptors in signaling and disease [3,8].
What is the MYD88 L265P mutation?
MYD88 L265P is an oncogenic point mutation that drives constitutive NF-kB activation in lymphoma and can be modeled using CRISPR knock-in.
What research methods are used to study GO:0045323?
Common methods include co-immunoprecipitation, RNA-seq, NF-kB reporter assays, flow cytometry, surface plasmon resonance, and CRISPR screens [1,5,8].
Conclusion
The interleukin-1 receptor complex (GO:0045323) is a central signaling hub for IL-1 family cytokines, composed of alpha and beta subunits that assemble upon ligand binding to activate NF-kB and MAPK pathways [1,5]. Its dysregulation contributes to cancer, kidney disease, and autoinflammatory disorders, making it a high-value target for therapeutic intervention [1,3,4]. CRISPR-based models, including knockout, point mutation, knock-in, and overexpression, provide powerful tools to dissect the molecular mechanisms and disease relevance of this complex [3,8]. EDITGENE offers comprehensive services to support these research efforts, from custom cell model generation to CRISPR library screening and bioinformatics analysis.
References
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- 2. Schmitz J et al.. 2005. IL-33, an interleukin-1-like cytokine that signals via the IL-1 receptor-related protein ST2 and induces T helper type 2-associated cytokines.. Immunity 23(5):479-90 PMID: 16286016
- 3. Zarezadeh Mehrabadi A et al.. 2024. Interleukin-1 receptor accessory protein (IL-1RAP): A magic bullet candidate for immunotherapy of human malignancies.. Crit Rev Oncol Hematol 193:104200 PMID: 37981104
- 4. Hu H et al.. 2024. Role of Interleukin 1 Receptor 2 in Kidney Disease.. J Interferon Cytokine Res 44(4):170-177 PMID: 38527174
- 5. Boraschi D et al.. 2013. The interleukin-1 receptor family.. Semin Immunol 25(6):394-407 PMID: 24246227
- 6. Stylianou E et al.. 1998. Interleukin-1.. Int J Biochem Cell Biol 30(10):1075-9 PMID: 9785472
- 8. Ngo VN et al.. 2011. Oncogenically active MYD88 mutations in human lymphoma.. Nature 470(7332):115-9 PMID: 21179087
