GO:0039529 RIG-I signaling pathway: Viral RNA Sensing, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0039529 (RIG-I signaling pathway) is the biological process triggered when the cytoplasmic receptor DDX58/RIG-I binds viral or pathogen-derived ssRNA or dsRNA.
• RIG-I activation initiates a signaling cascade that induces type I interferons and other cytokines to protect the host against infection.
• The pathway is tightly controlled by positive and negative regulators, including LGP2, DHX15, and multiple lncRNAs, to prevent excessive inflammation.
• Dysregulation of RIG-I signaling is linked to cancer immune evasion, viral susceptibility, and inflammatory pathology.
• Key experimental approaches include CRISPR knockout, point-mutation knock-in, overexpression, RNA-seq, and proteomics to dissect pathway components.
• EDITGENE provides CRISPR cell model services to study RIG-I signaling genes in a publication-ready manner.
Description
The RIG-I signaling pathway (GO:0039529) is a cytoplasmic innate immune sensing cascade that detects RNA from viruses and other pathogens. The pathway is initiated when the pattern recognition receptor RIG-I (encoded by DDX58) binds single-stranded or double-stranded RNA bearing specific molecular features, such as 5'-triphosphate or short double-stranded regions. This binding triggers a conformational change and downstream signaling that culminates in the expression of type I interferons and pro-inflammatory cytokines, establishing an antiviral state. Because of its central role in host defense, the RIG-I pathway is a major focus for researchers studying viral pathogenesis, autoimmunity, and cancer immunology. Understanding its molecular regulation and crosstalk with other innate immune sensors is essential for developing therapeutics that modulate antiviral responses. This article provides a research-grade overview of GO:0039529, including its definition, mechanism, key genes, disease associations, and experimental models.
RIG-I signaling pathway At A Glance
| GO ID | GO:0039529 |
|---|---|
| GO term | RIG-I signaling pathway |
| Ontology | biological_process |
| Synonym | DDX58 signaling pathway; retinoic acid inducible gene I signaling pathway; RIG-I-like receptor (RLR) signaling pathway; RIG-I signalling pathway; RIG-like helicase signaling pathway; RIG-like receptor signaling pathway; RLH signaling pathway; RLR signaling pathway |
| Major function | Detection of cytoplasmic viral or pathogen-derived RNA and induction of antiviral cytokine expression |
| Key receptor | RIG-I (DDX58) |
| Downstream effectors | MAVS, TBK1, IRF3/7, NF-kB |
| Primary outcome | Type I interferon and pro-inflammatory cytokine production |
What Is GO:0039529?
According to the Gene Ontology, GO:0039529 (RIG-I signaling pathway) is defined as the series of molecular signals initiated by the binding of ssRNA or dsRNA from another organism to the cytoplasmic pattern recognition receptor RIG-I (also known as DDX58). RIG-I detects RNA synthesized during viral replication or shed by non-viral pathogens, and triggers a signaling pathway to protect the host against infection, for example by inducing the expression of cytokines. In simpler terms, it is the process by which a cell senses foreign RNA in its cytoplasm and mounts an immune response.
Why Is RIG-I signaling pathway Important in Cell Biology?
The RIG-I signaling pathway is a cornerstone of cell-autonomous immunity against RNA viruses, and its proper regulation is critical for balancing effective antiviral defense with the prevention of harmful inflammation. Dysregulation of this pathway contributes to a wide range of human diseases, including viral infections, autoimmune disorders, and cancer. As a result, researchers across immunology, virology, and oncology study GO:0039529 to identify therapeutic targets and biomarkers.
• Provides the first line of defense against RNA viruses such as influenza, flaviviruses, and coronaviruses.
• Drives type I interferon production, which is essential for antiviral and immunomodulatory responses.
• Is implicated in cancer immune evasion, where RIG-I stability and signaling can influence tumor progression.
• Is regulated by a complex network of negative regulators, including LGP2 and lncRNAs, to prevent autoimmunity.
• Serves as a model system for understanding innate immune signal transduction and crosstalk with apoptosis.
• Offers targets for therapeutic modulation in viral infections and inflammatory diseases.
• Is conserved across vertebrates, with fish models providing insights into evolution and regulation.
• Enables high-throughput CRISPR screening to identify novel pathway components.
What Happens During RIG-I signaling pathway?
Viral RNA recognition by RIG-I
In simple terms: RIG-I acts like a security guard that spots foreign RNA in the cell's cytoplasm.
RIG-I (DDX58) is a cytoplasmic DExD/H-box helicase that specifically recognizes short double-stranded RNA or single-stranded RNA bearing a 5'-triphosphate moiety, which are typical of viral replication intermediates. Upon binding, RIG-I undergoes a conformational change that exposes its N-terminal caspase activation and recruitment domains (CARDs), enabling downstream signaling.
Signal transduction via MAVS and downstream kinases
In simple terms: Once RIG-I is activated, it passes the alarm to a mitochondrial protein called MAVS, which then activates a chain of kinases.
The exposed CARDs of RIG-I interact with the CARD domain of MAVS (mitochondrial antiviral signaling protein) on mitochondria, leading to MAVS aggregation and recruitment of downstream signaling complexes. This results in activation of TBK1 and IKK kinases, which phosphorylate and activate transcription factors IRF3, IRF7, and NF-kB.
Induction of interferon and cytokine expression
In simple terms: The activated transcription factors enter the nucleus and turn on genes that fight infection.
Phosphorylated IRF3/7 and NF-kB translocate to the nucleus and induce the expression of type I interferons (IFN-alpha/beta) and other pro-inflammatory cytokines. These secreted cytokines bind to their receptors on neighboring cells, triggering JAK-STAT signaling and expression of interferon-stimulated genes that establish an antiviral state.
Negative regulation and termination
In simple terms: The pathway has brakes to stop it from overreacting and causing damage.
Multiple negative regulators, including LGP2, RNF125, and various lncRNAs, act at different steps to dampen RIG-I signaling and prevent excessive inflammation. For example, LGP2 can sequester RNA ligands or interfere with RIG-I oligomerization, while lncRNAs can modulate the stability or activity of pathway components.
Crosstalk with apoptosis and other innate immune pathways
In simple terms: RIG-I signaling can also trigger cell death and cooperate with other sensors.
Recent studies show that DHX15 and RIG-I coordinate apoptosis and innate immune signaling through antiviral RNase L, linking RNA sensing to cell death pathways. Additionally, RIG-I signaling intersects with other PRR pathways, such as MDA5 and cGAS-STING, to shape the overall immune response.
Key Genes Involved in GO:0039529 RIG-I signaling pathway
The following genes and proteins are central to the RIG-I signaling pathway (GO:0039529) and are frequently studied in research settings.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DDX58 (RIG-I) | Cytoplasmic RNA sensor; initiates signaling upon binding viral RNA | Core receptor; target for KO, point mutation, and overexpression studies |
| MAVS | Mitochondrial adaptor protein; transmits signal from RIG-I to downstream kinases | Essential for pathway activation; knockout abolishes signaling |
| TBK1 | Kinase that phosphorylates IRF3/7 | Key effector kinase; target for inhibitor studies |
| IKKε | Kinase that phosphorylates IRF3/7 | Parallel to TBK1; involved in IRF activation |
| IRF3 | Transcription factor; induces type I interferon genes | Central to antiviral gene expression |
| IRF7 | Transcription factor; amplifies interferon production | Important for sustained IFN response |
| NF-kB | Transcription factor; induces pro-inflammatory cytokines | Links RIG-I to inflammatory responses |
| LGP2 | Negative regulator of RIG-I signaling | Modulates pathway to prevent autoimmunity |
| DHX15 | RNA helicase; coordinates apoptosis and immune signaling with RIG-I | Emerging player in RIG-I-mediated cell death |
| RNase L | Antiviral endoribonuclease; involved in apoptosis | Crosstalk with RIG-I pathway |
| RNF125 | E3 ubiquitin ligase; negatively regulates RIG-I | Controls RIG-I stability |
| USP3 | Deubiquitinase; stabilizes RIG-I | Positive regulator |
| TRIM25 | E3 ubiquitin ligase; ubiquitinates RIG-I CARDs | Essential for RIG-I activation |
| Riplet | E3 ubiquitin ligase; activates RIG-I | Positive regulator |
| NLRC5 | Regulator of RIG-I signaling | Modulates pathway activity |
| lncRNA-ACOD1 | lncRNA that regulates RIG-I signaling | Example of lncRNA-mediated regulation |
| lncRNA-MEG3 | lncRNA that modulates RIG-I pathway | Potential therapeutic target |
| ATG5-ATG12 | Autophagy-related complex; regulates RIG-I signaling | Links autophagy to innate immunity |
How Is RIG-I signaling pathway Regulated?
The RIG-I signaling pathway is subject to multilayered regulation to ensure robust antiviral responses while preventing autoimmunity. Positive regulators include E3 ubiquitin ligases such as TRIM25 and Riplet, which ubiquitinate RIG-I to promote its activation. Negative regulators include LGP2, RNF125, and several lncRNAs that interfere with RIG-I stability, oligomerization, or downstream signaling. Additionally, post-translational modifications such as phosphorylation and ubiquitination fine-tune pathway activity. In fish, negative regulation of RLR signaling has been documented, highlighting evolutionary conservation.
RIG-I signaling pathway and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DDX58 (RIG-I) | Viral susceptibility; cancer immune evasion | Knockout cell lines, point-mutation knock-in |
| MAVS | Antiviral immunity; inflammatory disorders | Knockout and overexpression models |
| LGP2 | Autoimmunity; viral infection | Knockout and overexpression in fish and mammalian cells |
| DHX15 | Apoptosis and immune signaling | Knockout and tagged knock-in |
| TRIM25 | Antiviral response; cancer | Point mutation and knockout |
RIG-I signaling in cancer immune evasion
Dysregulation of RIG-I signaling can promote tumor immune evasion. For example, asparagine availability drives immune evasion in bladder cancer by stabilizing RIG-I and modulating type I IFN signaling, suggesting that metabolic pathways can intersect with RIG-I activity. Targeting RIG-I signaling may enhance anti-tumor immunity.
RIG-I signaling in viral infections
The RIG-I pathway is critical for controlling RNA virus infections, including influenza, flaviviruses, and coronaviruses. Viruses have evolved mechanisms to antagonize RIG-I signaling, and understanding these interactions can inform antiviral drug development.
RIG-I signaling in autoimmune and inflammatory diseases
Excessive or prolonged RIG-I activation can lead to autoimmune conditions characterized by chronic type I interferon production. Negative regulators such as LGP2 and lncRNAs are important for preventing such pathology.
From RIG-I signaling pathway-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate RIG-I signaling? | CRISPR knockout cell line followed by RNA-seq and IFN reporter assay |
| What is the role of a specific phosphorylation site in RIG-I? | Point-mutation knock-in of phospho-deficient or phospho-mimetic variants |
| How does a disease-associated mutation affect RIG-I function? | Knock-in of the patient mutation in a cell line |
| Where does RIG-I localize during infection? | Tagged knock-in with fluorescent protein for imaging |
| Can overexpression of a negative regulator suppress RIG-I signaling? | Overexpression cell model with luciferase reporter |
| What are the global transcriptional changes upon RIG-I activation? | RNA-seq of wild-type and knockout cells treated with viral RNA |
How to Study the RIG-I signaling pathway Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Global gene expression changes | Identify interferon-stimulated genes and pathway signatures |
| Proteomics | Protein interactions and modifications | Discover novel regulators and post-translational modifications |
| Fluorescence microscopy | Subcellular localization and aggregation | Visualize RIG-I and MAVS dynamics |
| Luciferase reporter assay | Transcriptional activity of IFN-beta or NF-kB | High-throughput screening of pathway modulators |
| CRISPR knockout screening | Loss-of-function phenotypes for all genes | Identify essential pathway components |
| Co-immunoprecipitation | Protein-protein interactions | Validate interactions between RIG-I and regulators |
| Flow cytometry | Cytokine production at single-cell level | Measure IFN production in immune cells |
| Western blot | Protein expression and phosphorylation | Confirm knockout efficiency and signaling activation |
RNA sequencing (RNA-seq) to profile transcriptional responses
RNA-seq can be used to measure global changes in gene expression following RIG-I activation, such as induction of interferon-stimulated genes. Comparing wild-type and knockout cells reveals pathway-specific signatures.
Proteomics to identify interaction partners and post-translational modifications
Affinity purification coupled with mass spectrometry can identify proteins that interact with RIG-I or its regulators, as well as ubiquitination and phosphorylation events.
Imaging to visualize RIG-I localization and signaling complexes
Fluorescence microscopy of tagged RIG-I or MAVS can reveal their subcellular localization and aggregation upon viral RNA stimulation.
Reporter assays to quantify pathway activity
Luciferase reporters driven by interferon-beta or NF-kB promoters are commonly used to measure RIG-I signaling activity in high-throughput screens.
How CRISPR Can Be Used to Study GO:0039529 RIG-I signaling pathway
Knockout
CRISPR knockout of DDX58, MAVS, or downstream effectors can completely abolish RIG-I signaling, providing a clean background to study pathway requirements. Knockout cell lines are also useful for identifying off-target effects of chemical inhibitors.
Point Mutation
Point mutations can be introduced to study specific residues critical for RIG-I activation, such as ubiquitination sites or ATPase motifs. This allows precise dissection of molecular mechanisms without completely removing the protein.
Knock-in
Knock-in of tagged RIG-I (e.g., GFP or HA) enables visualization and biochemical purification of the receptor under endogenous regulation. Disease-associated mutations can also be knocked in to model patient-specific phenotypes.
Overexpression
Overexpression of RIG-I, MAVS, or negative regulators can amplify or suppress pathway activity, respectively, and is useful for gain-of-function studies and reporter assays.
How EDITGENE Supports RIG-I signaling pathway Research
Researchers studying RIG-I signaling pathway-related genes often need to determine whether a candidate gene is causally involved in antiviral responses or disease. EDITGENE provides a comprehensive suite of CRISPR cell model services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for RIG-I signaling pathway research.
Frequently Asked Questions About RIG-I signaling pathway
What is the RIG-I signaling pathway?
The RIG-I signaling pathway (GO:0039529) is a cellular process that detects viral or pathogen-derived RNA in the cytoplasm and triggers an immune response, including type I interferon production.
What genes are involved in RIG-I signaling?
Key genes include DDX58 (RIG-I), MAVS, TBK1, IKKε, IRF3, IRF7, NF-kB, and regulators such as LGP2, TRIM25, and RNF125.
What is the role of RIG-I in antiviral immunity?
RIG-I recognizes short double-stranded RNA or 5'-triphosphate RNA from viruses and initiates a signaling cascade that induces interferons and other cytokines to combat infection.
How is RIG-I signaling regulated?
It is regulated by positive factors like TRIM25 and Riplet, and negative regulators such as LGP2, RNF125, and various lncRNAs.
What diseases are associated with RIG-I signaling?
Dysregulation is linked to viral infections, autoimmune diseases, and cancer immune evasion.
What experimental models are used to study RIG-I signaling?
Common models include CRISPR knockout cell lines, point-mutation knock-ins, overexpression systems, and reporter assays.
How can CRISPR help study RIG-I signaling?
CRISPR enables knockout, knock-in, and point mutation of pathway genes to dissect their functions in antiviral responses.
What is the role of MAVS in RIG-I signaling?
MAVS is a mitochondrial adaptor that transmits the signal from RIG-I to downstream kinases, leading to IRF3/NF-kB activation.
Can RIG-I signaling be targeted for cancer therapy?
Yes, modulating RIG-I activity may enhance anti-tumor immunity, as shown by studies linking RIG-I stability to immune evasion in bladder cancer.
What methods are used to measure RIG-I signaling activity?
Methods include luciferase reporter assays, RNA-seq, proteomics, and imaging of tagged proteins.
Conclusion
The RIG-I signaling pathway (GO:0039529) is a fundamental innate immune sensing mechanism that protects hosts against RNA viruses and shapes inflammatory and anti-tumor responses. Its complex regulation by positive and negative factors ensures balanced immunity, and its dysregulation contributes to diverse diseases. Continued research using advanced CRISPR models and multi-omics approaches will further illuminate therapeutic opportunities. EDITGENE stands ready to support these efforts with tailored cell model services.
References
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- 3. van Huizen M et al.. 2025. The RIG-I-like receptor family of immune proteins.. Mol Cell 85(20):3793-3806 PMID: 41106369
- 4. Wei W et al.. 2025. Asparagine drives immune evasion in bladder cancer via RIG-I stability and type I IFN signaling.. J Clin Invest 135(8) PMID: 39964752
- 5. Quicke KM et al.. 2017. Negative regulators of the RIG-I-like receptor signaling pathway.. Eur J Immunol 47(4):615-628 PMID: 28295214
- 6. Ramnani B et al.. 2024. DHX15 and Rig-I Coordinate Apoptosis and Innate Immune Signaling by Antiviral RNase L.. Viruses 16(12) PMID: 39772220
- 7. Li T et al.. 2022. Duck LGP2 Downregulates RIG-I Signaling Pathway-Mediated Innate Immunity Against Tembusu Virus.. Front Immunol 13:916350 PMID: 35784309
- 8. Chang MX. 2021. The negative regulation of retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) signaling pathway in fish.. Dev Comp Immunol 119:104038 PMID: 33548290
