GO:0003724 RNA helicase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0003724 RNA helicase activity is defined as the unwinding of an RNA helix driven by ATP hydrolysis, also known as ATP-dependent RNA helicase activity.
• RNA helicases are essential for nearly every step of RNA metabolism, including transcription, splicing, ribosome assembly, translation, RNA decay, and innate immune sensing [1,8].
• Representative human RNA helicases include RIG-I (DDX58), DDX5, SKIV2L, YTHDC2, and Mtr4 (SKIV2L2/MTREX), each with distinct cellular functions [2,3,4,5,8].
• RNA helicase activity is tightly regulated by accessory domains, protein partners, post-translational modifications, and substrate RNA structures [1,8].
• Dysregulated RNA helicase activity is linked to viral infections, autoinflammatory diseases, cancer, and infertility [2,3,4,5].
• CRISPR-based knockout, point mutation, knock-in, and overexpression models are powerful tools for dissecting RNA helicase function in disease and development [1,5].
Description
RNA helicase activity (GO:0003724) is a fundamental molecular function that enables the unwinding of RNA duplexes using energy from ATP hydrolysis. This activity is required for virtually all aspects of RNA biology, from transcription and splicing to translation and RNA turnover [1,8]. The importance of RNA helicases is underscored by their evolutionary conservation and their involvement in diverse human diseases, including viral infections, cancer, and genetic disorders [2,3,4,5]. Researchers studying RNA helicase activity seek to understand its catalytic mechanism, regulation, and physiological roles, often using CRISPR-based genetic models to perturb specific helicase genes [1,5].
RNA helicase activity At A Glance
| GO ID | GO:0003724 |
|---|---|
| GO term | RNA helicase activity |
| Ontology | molecular_function |
| Synonym | ATP-dependent RNA helicase activity |
| Major function | Unwinding of RNA helices driven by ATP hydrolysis |
| EC number | Not specified in QuickGO |
| Representative genes | DDX58 (RIG-I), DDX5, SKIV2L, YTHDC2, MTREX (Mtr4) |
| Cellular processes | RNA metabolism, innate immunity, translation, RNA decay |
| Disease relevance | Viral infection, autoinflammation, cancer, infertility |
What Is GO:0003724?
GO:0003724 RNA helicase activity is defined by QuickGO as the unwinding of an RNA helix, driven by ATP hydrolysis. This molecular function is synonymous with ATP-dependent RNA helicase activity. It is a catalytic activity that couples the energy of ATP binding and hydrolysis to the separation of complementary RNA strands, thereby remodeling RNA structures or RNA-protein complexes.
Why Is RNA helicase activity Important in Cell Biology?
RNA helicase activity is essential for maintaining cellular RNA homeostasis and responding to environmental challenges. It governs the fate of coding and non-coding RNAs, influences gene expression programs, and is a first line of defense against RNA viruses [2,4]. Because of its central role, mutations or dysregulation of RNA helicases can lead to severe pathologies, making this activity a prime target for therapeutic intervention and a focus of intense biomedical research [1,3,5].
• Enables ribosome assembly and translation by resolving RNA structures [1,8].
• Required for pre-mRNA splicing and RNA export.
• Mediates innate immune sensing of viral RNA by RIG-I.
• Supports interferon signaling and antiviral defense [3,4].
• Regulates RNA stability and decay through exosome-associated helicases like Mtr4.
• Controls fertility via YTHDC2-mediated RNA unwinding.
• Implicated in cancer cell proliferation and survival [1,3].
• Dysregulated in autoinflammatory diseases such as Aicardi-Goutières syndrome.
• Target for antiviral and anticancer drug development [1,6].
• Provides mechanistic insights into ATP-dependent molecular machines [6,7].
What Happens During RNA helicase activity?
Substrate recognition and binding
In simple terms: The helicase first grabs onto the RNA molecule it needs to unwind.
RNA helicases recognize specific RNA structures or sequences through their conserved helicase core domains. For example, RIG-I binds short double-stranded RNA with a 5' triphosphate moiety, triggering a conformational change that activates its ATPase and helicase activities. Similarly, DDX5 binds structured regions in STAT1 mRNA to facilitate translation.
ATP binding and hydrolysis
In simple terms: The helicase uses ATP as an energy source to power unwinding.
ATP binding induces closure of the helicase core, while ATP hydrolysis and product release drive conformational cycling that translocates the helicase along the RNA strand. The ATPase activity of tick-borne encephalitis virus helicase is stimulated by RNA, demonstrating coupling between RNA binding and ATP hydrolysis. DEAD-box helicase Belle requires ATPase activity to promote gene expression in vivo.
RNA strand separation and translocation
In simple terms: The helicase pulls the RNA strands apart, one base pair at a time.
Processive helicases such as Mtr4 unwind RNA duplexes in a 3' to 5' direction, using a ratchet-like mechanism to separate strands. The energy from ATP hydrolysis is converted into mechanical force that disrupts base-pairing, allowing the helicase to translocate along the single-stranded RNA product.
Release and recycling
In simple terms: After unwinding, the helicase lets go of the RNA and can start again.
Following strand separation, ADP and inorganic phosphate are released, and the helicase returns to its open conformation. This cycle can be repeated multiple times, enabling processive unwinding of long RNA duplexes. Accessory factors and post-translational modifications can modulate the efficiency of this cycle [1,8].
Key Genes Involved in GO:0003724 RNA helicase activity
The following table lists representative genes encoding RNA helicases with demonstrated ATP-dependent RNA unwinding activity and their research relevance.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DDX58 (RIG-I) | Cytosolic viral RNA sensor; activates innate immunity | Antiviral signaling, autoimmunity |
| DDX5 | RNA helicase involved in transcription and translation | Hepatitis B virus replication, interferon signaling |
| SKIV2L | RNA helicase component of the SKI complex; regulates RNA decay | Antiviral defense, autoinflammation |
| YTHDC2 | RNA helicase essential for fertility; unwinds RNA independently of m6A | Meiosis, germ cell development |
| MTREX (Mtr4) | Nuclear RNA helicase; targets RNA to exosome for degradation | RNA quality control, ribosome biogenesis |
| DDX3X | RNA helicase involved in translation and splicing | Cancer, viral replication |
| EIF4A | RNA helicase that unwinds mRNA 5' UTR structures | Translation initiation, cancer |
| DDX6 | RNA helicase in P-body and translation repression | mRNA storage, decay |
| DHX9 | RNA helicase in transcription and RNA processing | Genome stability, cancer |
| DDX21 | RNA helicase in ribosome biogenesis | Cell proliferation, stress response |
| DDX1 | RNA helicase in RNA processing and export | Cancer, viral replication |
| DDX17 | RNA helicase in alternative splicing | Development, cancer |
| DDX39B | RNA helicase in mRNA export | Nuclear export, immunity |
| DDX41 | RNA helicase in innate immunity | Myeloid neoplasms, antiviral defense |
| DDX60 | RNA helicase in antiviral response | Interferon signaling |
| DHX36 | RNA helicase that resolves G-quadruplexes | Telomere maintenance, gene regulation |
| UPF1 | RNA helicase in nonsense-mediated decay | mRNA surveillance, disease |
| SKIV2L2 (MTREX) | RNA helicase in exosome targeting | RNA degradation, development |
How Is RNA helicase activity Regulated?
RNA helicase activity is regulated at multiple levels. Accessory domains and interacting proteins can stimulate or inhibit helicase function; for example, the SKI complex enhances SKIV2L activity to limit antiviral defense. Post-translational modifications such as phosphorylation can modulate helicase localization and activity. Substrate RNA structure and sequence also influence helicase recruitment and processivity [1,8]. In the case of YTHDC2, its RNA helicase activity is regulated by XRN1 and is essential for fertility independently of m6A recognition. Additionally, ATP availability and cellular energy status can indirectly affect helicase function.
RNA helicase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DDX58 (RIG-I) | Viral infection, autoinflammatory interferonopathies | Knockout mice, point-mutation knock-in |
| DDX5 | Hepatitis B virus infection, hepatocellular carcinoma | Liver-specific knockout, overexpression |
| SKIV2L | Trichohepatoenteric syndrome, autoinflammation | Knockout cell lines, patient iPSCs |
| YTHDC2 | Infertility, meiotic arrest | Knockout mice, point-mutation knock-in |
| MTREX (Mtr4) | RNA processing defects, developmental disorders | Knockout zebrafish, cell lines |
RNA helicases in viral infection and innate immunity
RIG-I (DDX58) is a cytosolic RNA helicase that senses double-stranded RNA from viruses and triggers interferon production. DDX5 promotes STAT1 mRNA translation and interferon signaling in hepatitis B virus-replicating hepatocytes, supporting antiviral defense. SKIV2L limits antiviral defense and autoinflammation elicited by the OAS-RNase L pathway, highlighting its role in preventing excessive immune activation.
RNA helicases in cancer
Many RNA helicases are overexpressed in cancers and contribute to tumor cell proliferation and survival by supporting translation and RNA processing. DDX5, for example, is implicated in hepatitis B virus-associated hepatocellular carcinoma through its role in interferon signaling. Targeting RNA helicase activity is being explored as an anticancer strategy.
RNA helicases in genetic disorders and infertility
Mutations in RNA helicase genes can cause developmental disorders and infertility. YTHDC2 helicase activity is essential for mouse fertility, and its loss leads to meiotic arrest. SKIV2L mutations are associated with trichohepatoenteric syndrome, a rare congenital disorder. These examples underscore the importance of precise helicase regulation in human health.
From RNA helicase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is the helicase essential for cell viability? | CRISPR knockout cell lines |
| Does a specific mutation affect ATP hydrolysis? | Point-mutation knock-in |
| How does the helicase interact with partners? | Tagged knock-in (e.g., GFP, FLAG) |
| What is the effect of helicase overexpression? | Overexpression stable cell lines |
| Which RNAs are directly unwound? | Crosslinking and immunoprecipitation (CLIP) |
| Does the helicase affect global translation? | Ribo-seq and polysome profiling |
How to Study the RNA helicase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro helicase assay | RNA strand separation | Enzymatic characterization |
| ATPase assay | ATP hydrolysis rate | Kinetic analysis |
| RNA-seq | Global RNA abundance | Transcriptome changes |
| Ribo-seq | Translation efficiency | Translational control |
| CLIP-seq | Direct RNA binding sites | Target identification |
| AP-MS | Protein-protein interactions | Complex composition |
| Cryo-EM | 3D structure | Mechanistic insights |
| Live-cell imaging | Subcellular localization | Dynamics |
Biochemical assays for helicase activity
In vitro helicase assays use synthetic RNA duplexes with a fluorescent or radioactive label to measure strand separation in the presence of ATP. ATPase activity can be monitored using NADH-coupled enzymatic assays or malachite green phosphate detection [6,7]. These methods provide quantitative kinetic parameters for helicase function.
Transcriptomic and translatomic profiling
RNA-seq and Ribo-seq can reveal global changes in RNA abundance and translation efficiency upon helicase perturbation. For example, knockout of DDX5 alters STAT1 mRNA translation, which can be detected by polysome profiling. CLIP-seq identifies direct RNA targets of helicases in living cells.
Proteomic and interactomic approaches
Affinity purification coupled with mass spectrometry (AP-MS) can identify protein partners of RNA helicases. Proximity labeling methods such as BioID can map interactomes in living cells. These approaches help define the molecular context of helicase function.
Structural biology and imaging
Cryo-electron microscopy and X-ray crystallography provide high-resolution structures of helicases in different nucleotide-bound states, revealing conformational changes during the catalytic cycle. Live-cell imaging of fluorescently tagged helicases can track their localization and dynamics.
How CRISPR Can Be Used to Study GO:0003724 RNA helicase activity
Knockout
CRISPR knockout of RNA helicase genes is used to assess loss-of-function phenotypes, such as defects in translation, RNA decay, or antiviral signaling. For example, knockout of SKIV2L leads to enhanced antiviral defense and autoinflammation. Knockout models help determine whether a helicase is essential for a given process.
Point Mutation
Point mutations in the helicase core can abolish ATP hydrolysis or RNA unwinding while preserving protein structure. Such knock-in models are valuable for separating helicase activity from other functions. For instance, mutations in the ATPase domain of Belle demonstrate the requirement for ATPase activity in gene expression.
Knock-in
Knock-in of epitope tags (e.g., GFP, FLAG) allows endogenous expression and localization studies. Tagged knock-in of Mtr4 has been used to study its interactions and recruitment to the exosome. Knock-in of disease-associated mutations can model human disorders in cells or animals.
Overexpression
Overexpression of wild-type or mutant RNA helicases can reveal gain-of-function effects and dominant-negative phenotypes. Overexpression of DDX5 enhances STAT1 translation and interferon signaling. Overexpression models are useful for drug screening and pathway analysis.
How EDITGENE Supports RNA helicase activity Research
Researchers studying RNA helicase activity-related genes often need to determine whether a candidate gene is causally involved in a specific cellular process or disease. This requires precise genetic manipulation, which can be achieved through CRISPR-based knockout, point mutation, knock-in, or overexpression models. EDITGENE provides comprehensive services to generate such models, enabling mechanistic studies and therapeutic target validation.
Contact EDITGENE today to design your custom CRISPR model for RNA helicase activity research.
Frequently Asked Questions About RNA helicase activity
What is RNA helicase activity?
RNA helicase activity (GO:0003724) is the unwinding of an RNA helix driven by ATP hydrolysis, also known as ATP-dependent RNA helicase activity.
What genes are involved in RNA helicase activity?
Key genes include DDX58 (RIG-I), DDX5, SKIV2L, YTHDC2, and MTREX (Mtr4), among many others [2,3,4,5,8].
How is RNA helicase activity regulated?
It is regulated by accessory proteins, post-translational modifications, substrate RNA structure, and ATP availability [1,4,5].
What diseases are associated with RNA helicase dysfunction?
Viral infections, autoinflammatory diseases, cancer, and infertility have been linked to RNA helicase dysfunction [2,3,4,5].
What methods are used to study RNA helicase activity?
Common methods include in vitro helicase assays, ATPase assays, RNA-seq, Ribo-seq, CLIP-seq, and structural biology [1,6,7,8].
Can CRISPR be used to study RNA helicase genes?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to dissect RNA helicase function [1,5].
What is the role of RIG-I in antiviral immunity?
RIG-I (DDX58) is an RNA helicase that senses double-stranded RNA and triggers innate antiviral responses.
How does DDX5 affect hepatitis B virus?
DDX5 enables STAT1 mRNA translation and interferon signaling in hepatitis B virus-replicating hepatocytes.
Why is YTHDC2 important for fertility?
YTHDC2 RNA helicase activity ensures mouse fertility by promoting meiotic progression independently of m6A recognition.
What is the function of Mtr4?
Mtr4 is an RNA helicase that targets RNA to the exosome for degradation and participates in ribosome biogenesis.
Conclusion
RNA helicase activity (GO:0003724) is a central molecular function that drives RNA unwinding in diverse biological processes, from innate immunity to translation and fertility. Its dysregulation contributes to viral infections, cancer, and genetic disorders. Continued research using advanced CRISPR models and multi-omics approaches will deepen our understanding of helicase mechanisms and open new therapeutic avenues.
References
- 1. Donsbach P et al.. 2021. Regulation of RNA helicase activity: principles and examples.. Biol Chem 402(5):529-559 PMID: 33583161
- 2. Yoneyama M et al.. 2004. The RNA helicase RIG-I has an essential function in double-stranded RNA-induced innate antiviral responses.. Nat Immunol 5(7):730-7 PMID: 15208624
- 3. Sun J et al.. 2022. RNA helicase DDX5 enables STAT1 mRNA translation and interferon signalling in hepatitis B virus replicating hepatocytes.. Gut 71(5):991-1005 PMID: 34021034
- 4. Yang K et al.. 2024. RNA helicase SKIV2L limits antiviral defense and autoinflammation elicited by the OAS-RNase L pathway.. EMBO J 43(18):3876-3894 PMID: 39112803
- 5. Li L et al.. 2022. The XRN1-regulated RNA helicase activity of YTHDC2 ensures mouse fertility independently of m(6)A recognition.. Mol Cell 82(9):1678-1690.e12 PMID: 35305312
- 6. Anindita PD et al.. 2022. Mechanistic insight into the RNA-stimulated ATPase activity of tick-borne encephalitis virus helicase.. J Biol Chem 298(10):102383 PMID: 35987382
- 7. Liao SE et al.. 2019. DEAD-box RNA helicase Belle posttranscriptionally promotes gene expression in an ATPase activity-dependent manner.. RNA 25(7):825-839 PMID: 30979781
- 8. Olsen KJ et al.. 2021. Mtr4 RNA helicase structures and interactions.. Biol Chem 402(5):605-616 PMID: 33857361
