GO:0004909 interleukin-1, type I, activating receptor activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004909 describes the molecular function of the interleukin-1 type I receptor (IL-1R1) in binding IL-1 and initiating intracellular signaling via adaptor proteins.
• The IL-1 system is a master regulator of innate immunity and inflammation, with IL-1R1 being the primary activating receptor for IL-1α and IL-1β.
• IL-1R1 signals through the MyD88-dependent pathway, leading to NF-κB and MAPK activation, which drives expression of inflammatory genes.
• Dysregulated IL-1R1 activity is implicated in atherosclerosis, neuroinflammation, and autoimmune diseases.
• IL-1R1 is expressed in diverse tissues including the hypothalamus, where it may influence neuroendocrine and behavioral responses.
• CRISPR-based models (knockout, knock-in, point mutation) are essential to dissect IL-1R1 function and its role in disease.
Description
Interleukin-1 (IL-1) is a pleiotropic cytokine that orchestrates innate immune responses and inflammation. The biological actions of IL-1 are mediated by the interleukin-1 type I receptor (IL-1R1), a transmembrane receptor that binds IL-1α and IL-1β and initiates signaling cascades. The Gene Ontology term GO:0004909, interleukin-1, type I, activating receptor activity, captures the molecular function of IL-1R1 in combining with IL-1 to trigger changes in cell activity via adaptor proteins. This function is fundamental to host defense but also contributes to chronic inflammatory diseases when dysregulated. Understanding the molecular details of IL-1R1 activation is critical for developing targeted therapies.
interleukin-1, type I, activating receptor activity At A Glance
| GO ID | GO:0004909 |
|---|---|
| GO term | interleukin-1, type I, activating receptor activity |
| Ontology | molecular_function |
| Synonym | IL-1 type I, activating binding; IL-1 type I, activating receptor; interleukin-1 activating receptor activity; interleukin-1, type I, activating binding; interleukin-1 type I receptor activity |
| Major function | Binding of interleukin-1 (IL-1α/IL-1β) and initiation of intracellular signaling via adaptor proteins such as MyD88. |
| Cellular location | Plasma membrane |
| Ligands | IL-1α, IL-1β |
| Adaptor proteins | MyD88, IRAK, TRAF6 |
| Downstream pathways | NF-κB, MAPK |
What Is GO:0004909?
GO:0004909 is defined as the molecular function of combining with interleukin-1 to initiate a change in cell activity via signaling pathways and mediated by adaptor proteins. In essence, it is the activity of the interleukin-1 type I receptor (IL-1R1) in binding IL-1 ligands and transducing signals into the cell, typically through the MyD88 adaptor protein.
Why Is interleukin-1, type I, activating receptor activity Important in Cell Biology?
The interleukin-1 type I activating receptor activity is a central node in innate immunity and inflammation. It mediates the primary response to IL-1, a cytokine involved in fever, acute phase response, and immune cell activation. Dysregulation of this receptor activity is linked to a wide range of pathologies, including atherosclerosis, neuroinflammation, and autoimmune disorders. Therefore, understanding GO:0004909 is essential for both basic immunology and therapeutic development.
• Mediates the biological effects of IL-1, a key pro-inflammatory cytokine.
• Activates NF-κB and MAPK pathways, driving expression of inflammatory genes.
• Plays a role in atherosclerosis by promoting macrophage activation and vascular inflammation.
• Expressed in the hypothalamus, suggesting roles in neuroendocrine and behavioral responses.
• Involved in host defense against infections.
• Contributes to autoimmune and autoinflammatory diseases.
• Target for anti-inflammatory therapies (e.g., anakinra).
• Essential for IL-1 signaling in various cell types, including macrophages and endothelial cells.
• Its activity can be modulated by decoy receptors and antagonists.
• Studied using CRISPR models to dissect gene function in disease.
What Happens During interleukin-1, type I, activating receptor activity?
Ligand Binding and Receptor Dimerization
In simple terms: IL-1 binds to the receptor, causing it to pair up and start a signal.
The interleukin-1 type I receptor (IL-1R1) binds IL-1α or IL-1β with high affinity. Upon ligand binding, IL-1R1 recruits the IL-1 receptor accessory protein (IL-1RAcP) to form a heterodimeric complex, which is essential for signal transduction.
Recruitment of Adaptor Proteins
In simple terms: The receptor complex grabs adaptor proteins inside the cell to pass the message.
The dimerized receptor complex recruits the adaptor protein MyD88 through TIR domain interactions. MyD88 then associates with IRAK kinases, forming the Myddosome complex, which is a critical step in IL-1 signaling.
Activation of Downstream Signaling Pathways
In simple terms: The signal travels through a chain of proteins to turn on inflammatory genes.
The Myddosome activates TRAF6, which leads to activation of TAK1 and subsequent phosphorylation of IKK. This results in NF-κB activation and translocation to the nucleus, as well as activation of MAPK pathways (e.g., JNK, p38), driving transcription of pro-inflammatory genes.
Cellular Responses and Feedback
In simple terms: The cell responds by producing inflammatory molecules and can later shut down the signal.
Activation of NF-κB and MAPK leads to expression of cytokines, chemokines, and adhesion molecules. Negative feedback mechanisms, including upregulation of decoy receptors (IL-1R2) and antagonists (IL-1Ra), help resolve inflammation.
Key Genes Involved in GO:0004909 interleukin-1, type I, activating receptor activity
The following genes and proteins are key components of the interleukin-1 type I activating receptor activity and its signaling network.
| Gene | Major Role | Research Relevance |
|---|---|---|
| IL1R1 | Interleukin-1 receptor type 1; binds IL-1 and initiates signaling | Central to GO:0004909; knockout models used to study IL-1 signaling |
| IL1B | Interleukin-1 beta; major ligand for IL-1R1 | Key pro-inflammatory cytokine; knockout mice used in inflammation studies |
| IL1A | Interleukin-1 alpha; ligand for IL-1R1 | Involved in acute inflammation; studied in skin and immune cells |
| IL1RAP | IL-1 receptor accessory protein; required for signaling | Essential for IL-1R1 signal transduction; knockout blocks IL-1 responses |
| MYD88 | Myeloid differentiation primary response 88; adaptor protein | Critical for IL-1R1 signaling; knockout mice are impaired in IL-1 responses |
| IRAK1 | Interleukin-1 receptor-associated kinase 1 | Kinase recruited to receptor complex; regulates NF-κB activation |
| IRAK4 | Interleukin-1 receptor-associated kinase 4 | Kinase essential for Myddosome formation; mutations cause immunodeficiency |
| TRAF6 | TNF receptor-associated factor 6 | E3 ubiquitin ligase; activates TAK1 and downstream pathways |
| NFKB1 | Nuclear factor kappa B subunit 1 | Transcription factor activated by IL-1R1 signaling |
| MAPK14 | Mitogen-activated protein kinase 14 (p38 alpha) | Mediates stress responses downstream of IL-1R1 |
| IL1RN | Interleukin-1 receptor antagonist | Competes with IL-1 for IL-1R1 binding; anti-inflammatory |
| IL1R2 | Interleukin-1 receptor type 2; decoy receptor | Binds IL-1 without signaling; negative regulator |
| TOLLIP | Toll interacting protein | Regulates IL-1R1 signaling by modulating IRAK1 |
| PELI1 | Pellino E3 ubiquitin protein ligase 1 | Scaffold for IRAK1 and TRAF6; modulates NF-κB |
| UBE2N | Ubiquitin conjugating enzyme E2 N | Involved in TRAF6-mediated ubiquitination |
| TAB1 | TAK1 binding protein 1 | Regulatory subunit of TAK1 complex |
| TAB2 | TAK1 binding protein 2 | Regulatory subunit of TAK1 complex |
| NFKBIA | NFKB inhibitor alpha | Inhibits NF-κB; feedback regulator |
How Is interleukin-1, type I, activating receptor activity Regulated?
The interleukin-1 type I activating receptor activity is tightly regulated at multiple levels. Ligand availability is controlled by decoy receptors (IL-1R2) and the natural antagonist IL-1Ra (IL1RN), which compete for IL-1R1 binding. Receptor expression levels are modulated by cytokines and inflammatory stimuli. Intracellularly, signaling is regulated by phosphorylation and ubiquitination of IRAK kinases and TRAF6, as well as by negative feedback proteins such as TOLLIP and IRAK-M. Additionally, shedding of IL-1R1 ectodomain can downregulate surface receptor levels.
interleukin-1, type I, activating receptor activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| IL1R1 | Atherosclerosis, neuroinflammation | IL1R1 knockout mice, macrophage-specific KO |
| IL1B | Autoinflammatory diseases, atherosclerosis | IL1B knockout mice, point mutation knock-in |
| IL1RN | DIRA (deficiency of IL-1 receptor antagonist) | IL1RN knockout mice, knock-in of patient mutations |
| MYD88 | Immunodeficiency, inflammation | MYD88 knockout mice, conditional KO |
| IL1RAP | Inflammation, cancer | IL1RAP knockout mice, overexpression models |
Atherosclerosis and Cardiovascular Disease
IL-1R1 signaling promotes vascular inflammation and atherosclerotic plaque development. Macrophage olfactory receptor 2-driven atherosclerosis is potentiated by IL-1/Toll-like receptor signaling, highlighting the role of GO:0004909 in cardiovascular pathology.
Neuroinflammation and Hypothalamic Function
IL-1R1 is expressed in the human hypothalamus, where it may mediate neuroendocrine and behavioral effects of IL-1, such as fever and sickness behavior. Dysregulated IL-1 signaling in the brain contributes to neuroinflammation in neurodegenerative diseases.
Autoinflammatory and Autoimmune Diseases
Mutations in IL-1 pathway components, including IL1RN, cause autoinflammatory syndromes. IL-1R1 activity is also implicated in rheumatoid arthritis and other autoimmune conditions.
From interleukin-1, type I, activating receptor activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does IL1R1 mediate IL-1-induced NF-κB activation? | IL1R1 knockout cell lines (e.g., HEK293, macrophages) |
| What is the effect of a specific IL1R1 point mutation on ligand binding? | Point mutation knock-in via CRISPR in cell lines |
| How does IL1R1 signaling contribute to atherosclerosis? | ApoE-/- mice with IL1R1 knockout |
| Can we tag endogenous IL1R1 for imaging? | Knock-in of fluorescent tag (e.g., GFP) at IL1R1 locus |
| What is the effect of IL1R1 overexpression in neurons? | Overexpression of IL1R1 in transgenic mice or cell lines |
| Does IL1R1 signaling regulate hypothalamic function? | Hypothalamic-specific IL1R1 knockout mice |
How to Study the interleukin-1, type I, activating receptor activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss of gene function | Validate IL1R1 requirement in IL-1 signaling |
| RNA-seq | Transcriptional changes | Identify IL-1R1 target genes |
| Phosphoproteomics | Phosphorylation events | Map signaling pathways downstream of IL-1R1 |
| Co-immunoprecipitation | Protein-protein interactions | Detect IL-1R1-MyD88 complex |
| Luciferase reporter assay | NF-κB activity | Measure IL-1-induced NF-κB activation |
| Flow cytometry | Surface IL-1R1 expression | Quantify receptor levels on immune cells |
| ELISA | Cytokine production | Measure IL-6 or TNF-α after IL-1 stimulation |
| Immunofluorescence | Subcellular localization | Visualize IL-1R1 trafficking |
CRISPR-Cas9 Knockout
Knockout of IL1R1 or downstream signaling components using CRISPR-Cas9 is a powerful approach to study GO:0004909. Loss-of-function models can confirm the requirement of IL1R1 for IL-1-induced responses.
RNA Sequencing (RNA-seq)
RNA-seq can profile transcriptional changes downstream of IL-1R1 activation, identifying NF-κB and MAPK target genes. This helps define the cellular programs controlled by GO:0004909.
Proteomics and Phosphoproteomics
Mass spectrometry-based proteomics can identify protein interactions and phosphorylation events in the IL-1R1 signaling complex, such as IRAK and TRAF6 modifications.
Imaging and Reporter Assays
Fluorescent tagging of IL1R1 or NF-κB reporters allows real-time visualization of receptor trafficking and signaling activation in live cells.
How CRISPR Can Be Used to Study GO:0004909 interleukin-1, type I, activating receptor activity
Knockout
CRISPR knockout of IL1R1 or its signaling partners (e.g., MYD88, IRAK4) generates cell models to study the loss of GO:0004909. These models are used to confirm the specificity of IL-1 responses and to identify downstream effectors.
Point Mutation
Introducing point mutations in IL1R1 (e.g., in the ligand-binding domain or TIR domain) via CRISPR base editing or HDR allows structure-function analysis of receptor activation and adaptor recruitment.
Knock-in
Knock-in of epitope tags (e.g., FLAG, HA) or fluorescent proteins at the endogenous IL1R1 locus enables tracking of receptor expression, localization, and interaction partners in a physiological context.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of IL1R1 can model gain-of-function states and amplify IL-1 signaling, useful for studying chronic inflammation and cancer.
How EDITGENE Supports interleukin-1, type I, activating receptor activity Research
Researchers studying interleukin-1, type I, activating receptor activity-related genes often need to determine whether a candidate gene is causally involved in IL-1 signaling and disease. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell and animal models, enabling rigorous functional studies of GO:0004909.
Contact EDITGENE today to design your custom CRISPR model for interleukin-1, type I, activating receptor activity research.
Frequently Asked Questions About interleukin-1, type I, activating receptor activity
What is GO:0004909?
GO:0004909 is the Gene Ontology term for interleukin-1, type I, activating receptor activity, describing the function of IL-1R1 in binding IL-1 and initiating intracellular signaling via adaptor proteins.
What genes are involved in interleukin-1, type I, activating receptor activity?
Key genes include IL1R1, IL1RAP, MYD88, IRAK1, IRAK4, TRAF6, and downstream effectors like NFKB1 and MAPK14.
What diseases are associated with IL-1R1 signaling?
IL-1R1 signaling is implicated in atherosclerosis, neuroinflammation, autoinflammatory diseases, and certain cancers.
How is interleukin-1, type I, activating receptor activity regulated?
It is regulated by decoy receptors (IL-1R2), antagonist IL-1Ra, and intracellular feedback mechanisms involving TOLLIP and IRAK-M.
What is the role of MyD88 in IL-1R1 signaling?
MyD88 is the primary adaptor protein recruited to IL-1R1 upon ligand binding, essential for downstream NF-κB and MAPK activation.
Can CRISPR be used to study IL-1R1 function?
Yes, CRISPR knockout, point mutation, and knock-in models are widely used to dissect IL-1R1 signaling and its role in disease.
What cell types express IL-1R1?
IL-1R1 is expressed in many cell types, including macrophages, endothelial cells, fibroblasts, and neurons, particularly in the hypothalamus.
What are the downstream pathways of IL-1R1?
IL-1R1 activates NF-κB and MAPK pathways, leading to expression of pro-inflammatory cytokines and other immune response genes.
Is IL-1R1 a therapeutic target?
Yes, blocking IL-1R1 signaling with antagonists like anakinra is used to treat autoinflammatory diseases, and ongoing research explores its role in atherosclerosis.
How can I model IL-1R1 mutations in the lab?
EDITGENE offers CRISPR-based point mutation and knock-in services to create isogenic cell lines carrying specific IL1R1 mutations for functional studies.
Conclusion
The interleukin-1 type I activating receptor activity (GO:0004909) is a cornerstone of innate immunity and inflammation. Its dysregulation contributes to a spectrum of diseases, from atherosclerosis to neuroinflammation. Advances in CRISPR genome editing have revolutionized our ability to study this receptor function in physiologically relevant models. EDITGENE's comprehensive services empower researchers to generate precise genetic models and accelerate discoveries in IL-1 biology.
References
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- 7. Zhang L et al.. 2025. Interleukin-1/Toll-like receptor signaling potentiates macrophage olfactory receptor 2-driven atherosclerosis.. Cell Rep 44(12):116639 PMID: 41343277
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