GO:0017130 poly(C) RNA binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0017130 poly(C) RNA binding is a molecular function defined as binding to a sequence of cytosine residues in an RNA molecule.
• The poly(C)-binding proteins (PCBPs) are the principal known effectors of poly(C) RNA binding and act as RNA-binding regulators of gene expression.
• Poly(C) RNA binding is mediated by KH domains, as shown by structural and RNA-binding studies of the third KH domain of PCBP1.
• Poly(C)-sensitive RNA-binding complexes regulate the stability of neurofilament mRNAs, linking this function to neuronal RNA metabolism.
• Poly(C) RNA binding is experimentally probed with poly(C) or poly(I:C) RNA ligands in antiviral, immune and cancer models.
• CRISPR knockout, point-mutation, knock-in and overexpression cell models enable causal testing of genes encoding poly(C) RNA-binding proteins.
Description
GO:0017130 poly(C) RNA binding is a molecular function ontology term defined as binding to a sequence of cytosine residues in an RNA molecule. It describes the selective recognition of cytosine-rich RNA tracts by RNA-binding proteins, a property historically used to define the poly(C)-binding protein (PCBP) family. Because cytosine-rich sequences occur in many cellular and viral RNAs, poly(C) RNA binding is relevant to post-transcriptional control of gene expression and to host-pathogen interactions. The function is not restricted to a single protein; several KH-domain proteins can recognize poly(C) RNA, and the third KH domain of PCBP1 has been structurally and biochemically characterized for its RNA-binding activity. In parallel, synthetic poly(C)-containing or poly(I:C) RNA ligands have been used to trigger and measure poly(C)-dependent RNA-sensing responses in immune and tumor models. For researchers, GO:0017130 therefore provides a precise annotation target when studying RNA-binding proteins, RNA stability complexes and antiviral or inflammatory signaling.
poly(C) RNA binding At A Glance
| GO ID | GO:0017130 |
|---|---|
| GO term | poly(C) RNA binding |
| Ontology | molecular_function |
| Definition | Binding to a sequence of cytosine residues in an RNA molecule. |
| Synonym | poly(C) binding; poly(rC) binding |
| Major function | Sequence-selective recognition of cytosine-rich RNA by RNA-binding proteins |
| Representative effectors | Poly(C)-binding proteins (PCBPs) and KH-domain RNA-binding proteins |
| Associated biology | Post-transcriptional gene regulation, mRNA stability and antiviral RNA sensing |
| Experimental ligands | Poly(C) RNA and poly(I:C) RNA complexes used in immune and cancer studies |
What Is GO:0017130?
In simple terms, GO:0017130 poly(C) RNA binding means a protein physically binds to a run of cytosine nucleotides within an RNA molecule. The QuickGO definition states that this molecular function is the binding to a sequence of cytosine residues in an RNA molecule. It is a binding function, not a catalytic activity, and it is annotated to proteins that selectively recognize cytosine-rich RNA. The synonym poly(rC) binding reflects the same activity. This function is distinct from general double-stranded RNA binding or sequence-independent RNA association because it depends on cytosine-rich sequence recognition, as illustrated by the RNA-binding specificity of PCBP KH domains and by poly(C)-sensitive RNA-binding complexes.
Why Is poly(C) RNA binding Important in Cell Biology?
Poly(C) RNA binding is important because it provides a sequence-specific handle for understanding how cells control RNA fate and how they detect foreign or aberrant RNA. The poly(C)-binding proteins are established transcriptional and post-transcriptional regulators of gene expression, and their RNA recognition is structurally encoded in KH domains. Poly(C)-sensitive RNA-binding complexes regulate the stability of neurofilament mRNAs, directly connecting this function to neuronal RNA metabolism. In immunity, poly(I:C)-based and poly(C)-related RNA ligands are widely used to activate antiviral and inflammatory responses, and proteins such as ZNFX1 and GBP1 modulate these responses. In cancer models, poly(I:C) RNA complexes have been explored as therapeutics, showing that poly(C)-related RNA recognition has translational relevance. Consequently, GO:0017130 is a useful annotation for mechanistic, disease and drug-discovery studies of RNA-binding proteins.
• Defines a sequence-selective RNA-binding activity that distinguishes cytosine-rich RNA from other RNA sequences.
• Underpins the function of poly(C)-binding proteins as regulators of gene expression.
• Contributes to mRNA stability control, including neurofilament mRNA stability complexes.
• Is relevant to antiviral RNA sensing pathways involving poly(I:C) and related RNA ligands.
• Is connected to cytokine and chemokine regulation in macrophages exposed to poly(I:C).
• Has been explored in cancer therapy models using poly(I:C) RNA complexes.
• Provides a molecular annotation for KH-domain RNA-binding proteins.
• Supports research on host-pathogen interactions and innate immune RNA recognition.
• Enables CRISPR-based causal testing of genes encoding poly(C) RNA-binding proteins.
• Links RNA-binding biochemistry to disease models such as melanoma and immune disorders.
Molecular Mechanism of poly(C) RNA binding
Cytosine-rich RNA recognition
In simple terms: The protein looks for a stretch of C letters in the RNA and grabs onto it.
Poly(C) RNA binding begins with sequence-selective recognition of cytosine-rich tracts. The poly(C)-binding proteins were originally defined by this property, and their multiplicity of functions has been linked to distinct RNA-recognition modes. Structural work on the third KH domain of PCBP1 demonstrated the molecular basis of RNA binding by this domain, showing how a KH fold engages RNA. This recognition step is the defining event of GO:0017130 and distinguishes it from non-specific RNA association.
KH-domain RNA engagement
In simple terms: A specialized protein module called a KH domain holds the RNA.
KH domains are recurrent RNA-binding modules in poly(C)-binding proteins. The third KH domain of PCBP1 has been characterized for both structure and RNA binding, providing direct evidence that KH domains mediate poly(C) RNA recognition. The poly(C)-binding protein family is defined by such domains and by a multiplicity of functions, which has motivated a search for shared and distinct mechanisms. This subsection explains how the binding function is physically executed at the domain level.
RNA stability complex formation
In simple terms: After binding, the protein can join a team that decides whether the RNA survives or is degraded.
Poly(C)-sensitive RNA-binding complexes regulate the stability of the heavy and light neurofilament mRNAs, showing that poly(C) RNA binding can be coupled to mRNA stability control. These complexes illustrate that the function is not merely a binding event but can be part of a larger ribonucleoprotein assembly that influences RNA half-life. This connects GO:0017130 to post-transcriptional gene regulation.
Poly(I:C) and antiviral RNA sensing
In simple terms: Synthetic C-rich RNA mimics can trigger the cell's antiviral alarm.
Poly(I:C) is a widely used synthetic RNA ligand that activates antiviral responses, and mitochondria-localised ZNFX1 functions as a dsRNA sensor to initiate antiviral responses through MAVS. GBP1 alters the expression of poly(I:C)-induced cytokines and chemokines and MAP kinases in macrophages, showing that poly(I:C)-driven responses are modulated by specific proteins. These studies provide experimental contexts in which poly(C)-related RNA recognition is functionally probed.
Therapeutic and cancer model context
In simple terms: C-rich RNA complexes have been tested as anti-cancer agents in models.
Zinc oxide nanoparticle-poly I:C RNA complexes have been studied as therapeutics against experimental melanoma, demonstrating that poly(I:C) RNA complexes can be applied in cancer models. This subsection places poly(C) RNA binding in a translational context, while noting that the cited study concerns poly(I:C) RNA complexes rather than a direct demonstration of GO:0017130 for every component. It illustrates how RNA-binding and RNA-sensing biology can be exploited experimentally.
Key Genes Involved in GO:0017130 poly(C) RNA binding
The following genes and proteins are directly or experimentally linked to poly(C) RNA binding and its associated RNA-sensing biology in the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PCBP1 | Poly(C)-binding protein with KH-domain RNA recognition | Third KH domain structurally and biochemically characterized for RNA binding |
| PCBP2 | Poly(C)-binding protein family member | Part of the PCBP family with multiple functions and mechanisms |
| PCBP3 | Poly(C)-binding protein family member | Contributes to the multiplicity of PCBP functions |
| PCBP4 | Poly(C)-binding protein family member | Contributes to the multiplicity of PCBP functions |
| HNRNPK | KH-domain RNA-binding protein related to poly(C) RNA recognition | Representative of poly(C)-binding protein biology |
| ZNFX1 | Mitochondria-localised dsRNA sensor acting through MAVS | Antiviral RNA-sensing model relevant to poly(I:C) responses |
| MAVS | Mitochondrial antiviral signaling adaptor | Downstream of ZNFX1 dsRNA sensing |
| GBP1 | Guanylate binding protein 1 | Alters poly(I:C)-induced cytokines, chemokines and MAP kinases in macrophages |
| IFITM1 | Interferon-induced transmembrane protein | Studied in placental syncytiotrophoblast formation and fetal demise |
| IFITM2 | Interferon-induced transmembrane protein | Studied in placental syncytiotrophoblast formation and fetal demise |
| IFITM3 | Interferon-induced transmembrane protein | Studied in placental syncytiotrophoblast formation and fetal demise |
| NEFL | Neurofilament light mRNA | Stability regulated by poly(C)-sensitive RNA-binding complexes |
| NEFH | Neurofilament heavy mRNA | Stability regulated by poly(C)-sensitive RNA-binding complexes |
| NEFM | Neurofilament medium mRNA | Neurofilament mRNA stability context for poly(C)-sensitive complexes |
| MAPK1 | MAP kinase pathway component | Modulated in poly(I:C)-stimulated macrophages |
| MAPK3 | MAP kinase pathway component | Modulated in poly(I:C)-stimulated macrophages |
| MAVS-associated sensors | RNA-sensing pathway components | Antiviral response context for poly(I:C) RNA |
How Is poly(C) RNA binding Regulated?
Poly(C) RNA binding is regulated at multiple levels. At the RNA level, the availability of cytosine-rich sequence elements determines whether a poly(C)-binding protein can engage its target, as illustrated by poly(C)-sensitive complexes that regulate neurofilament mRNA stability. At the protein level, the presence and arrangement of KH domains determine RNA-binding competence, as shown for the third KH domain of PCBP1. At the pathway level, poly(I:C)-induced responses are modulated by proteins such as GBP1, which alters cytokine, chemokine and MAP kinase expression in macrophages, and by sensors such as ZNFX1 that initiate antiviral signaling through MAVS. These layers together shape the functional output of poly(C) RNA binding in cells.
poly(C) RNA binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NEFL | Neurofilament mRNA stability and neuronal biology | Neuronal cell line with knockout of poly(C)-binding protein |
| NEFH | Neurofilament mRNA stability and neuronal biology | Neuronal cell line with knockout of poly(C)-binding protein |
| ZNFX1 | Antiviral RNA sensing through MAVS | Knockout or overexpression in immune cells followed by poly(I:C) stimulation |
| GBP1 | Poly(I:C)-induced cytokine and MAP kinase regulation | Macrophage knockout or overexpression with poly(I:C) treatment |
| IFITM1/2/3 | Placental syncytiotrophoblast formation and fetal demise | Trophoblast model with knockout or overexpression of IFITM proteins |
Neurodegeneration and neurofilament mRNA stability
Poly(C)-sensitive RNA-binding complexes regulate the stability of the heavy and light neurofilament mRNAs, which are central to neuronal cytoskeletal integrity. Dysregulation of such RNA stability control is relevant to neurodegenerative contexts in which neurofilament mRNA levels are altered. This links GO:0017130 to neuronal RNA metabolism and to disease models focused on neurofilament biology.
Antiviral immunity and inflammatory signaling
Poly(I:C) RNA is a classic trigger of antiviral responses, and ZNFX1 functions as a dsRNA sensor that initiates antiviral responses through MAVS. GBP1 alters poly(I:C)-induced cytokines, chemokines and MAP kinases in macrophages, showing that specific proteins tune the inflammatory output of RNA sensing. These findings connect poly(C)-related RNA recognition to innate immune regulation and inflammatory disease research.
Cancer and RNA-based therapeutics
Zinc oxide nanoparticle-poly I:C RNA complexes have been investigated as therapeutics against experimental melanoma, demonstrating that poly(I:C) RNA complexes can be deployed in cancer models. This provides a translational disease context for RNA-binding and RNA-sensing biology related to poly(C) RNA. It supports the use of such models to test RNA-based therapeutic strategies.
Placental development and fetal demise
IFITM proteins inhibit placental syncytiotrophoblast formation and promote fetal demise, as shown in a study of these interferon-induced proteins. Although this study concerns IFITM proteins rather than poly(C) RNA binding directly, it illustrates how RNA- and interferon-related pathways can influence placental development. It is included here as a disease-relevant context for RNA-binding and antiviral biology.
From poly(C) RNA binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does a candidate gene mediate poly(C) RNA binding? | Knockout cell model with poly(C) RNA pull-down |
| Does a specific KH-domain residue control RNA binding? | Point-mutation knock-in of the KH domain |
| Does a disease-associated variant alter RNA binding? | Knock-in of the variant followed by RNA-binding assays |
| Where does the protein localize and bind RNA? | Tagged knock-in with imaging and RNA immunoprecipitation |
| Does overexpression change RNA stability or signaling? | Overexpression cell model with RNA stability assays |
| Which pathways depend on the RNA-binding protein? | CRISPR library screening and bioinformatics analysis |
How to Study the poly(C) RNA binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA pull-down | Direct binding to poly(C) RNA | Validate candidate poly(C) RNA-binding proteins |
| Electrophoretic mobility shift assay | Protein-RNA complex formation | Test KH-domain RNA binding |
| RNA immunoprecipitation | In vivo RNA targets | Map poly(C)-rich RNA targets |
| RNA-seq | Transcriptome changes | Assess downstream effects of RNA-binding proteins |
| RNA stability assay | Target mRNA half-life | Study neurofilament mRNA stability |
| Poly(I:C) stimulation assay | Antiviral and inflammatory response | Test RNA-sensing pathways |
| CRISPR knockout screening | Gene requirement | Identify genes needed for poly(C) RNA-related phenotypes |
RNA-binding assays
Poly(C) RNA binding can be measured with RNA pull-down, electrophoretic mobility shift assays and related biochemical methods. Structural and RNA-binding studies of the third KH domain of PCBP1 provide a template for domain-level binding assays. Poly(C)-sensitive complexes regulating neurofilament mRNA stability illustrate how binding can be linked to functional RNA stability readouts.
Transcriptomics and RNA stability profiling
RNA-seq and RNA stability measurements can reveal the consequences of poly(C) RNA binding on target transcripts. Poly(C)-sensitive complexes regulate neurofilament mRNA stability, making stability profiling a direct functional assay. Poly(I:C)-induced cytokine and chemokine changes in macrophages can also be profiled by transcriptomics.
Immune and antiviral functional assays
Poly(I:C) stimulation followed by cytokine, chemokine and MAP kinase readouts is a standard way to probe RNA-sensing pathways. ZNFX1-dependent antiviral signaling through MAVS provides a mechanistic framework for such assays. GBP1-dependent modulation of poly(I:C)-induced responses in macrophages provides a specific example of functional readouts.
Cancer and therapeutic models
Poly(I:C) RNA complexes have been tested in experimental melanoma, providing a cancer model for RNA-based interventions. Such models can be combined with knockout or overexpression of candidate RNA-binding proteins to test causality. This approach connects molecular RNA-binding studies to translational cancer research.
How CRISPR Can Be Used to Study GO:0017130 poly(C) RNA binding
Knockout
CRISPR knockout of genes encoding poly(C) RNA-binding proteins can test whether the protein is required for RNA binding, RNA stability or downstream signaling. For example, knocking out a PCBP family member allows assessment of its contribution to poly(C) RNA recognition. Knockout of ZNFX1 or GBP1 can be used to test antiviral and poly(I:C)-induced responses.
Point Mutation
Point mutation of KH-domain residues can dissect the structural basis of poly(C) RNA binding. The third KH domain of PCBP1 has been characterized for RNA binding, providing a rationale for targeted mutation of key residues. Such mutants can be compared with wild-type protein in RNA-binding assays to establish causality.
Knock-in
Knock-in of disease-associated variants or tagged alleles enables study of poly(C) RNA binding in a physiological context. Tagged knock-in allows imaging and RNA immunoprecipitation of the endogenous protein. This approach is useful for linking sequence variants to altered RNA-binding function.
Overexpression
Overexpression of poly(C) RNA-binding proteins can reveal gain-of-function effects on RNA stability and signaling. Overexpression models are also useful for testing whether increased RNA binding alters poly(I:C)-induced cytokine and MAP kinase responses. Such models complement knockout studies by providing bidirectional perturbation.
How EDITGENE Supports poly(C) RNA binding Research
Researchers studying poly(C) RNA binding-related genes often need to determine whether a candidate gene is causally involved in RNA recognition, RNA stability or downstream signaling. EDITGENE provides CRISPR-based cell model services that enable knockout, point-mutation, knock-in and overexpression studies of genes encoding poly(C) RNA-binding proteins and related RNA-sensing factors.
Contact EDITGENE today to design your custom CRISPR model for poly(C) RNA binding research.
Frequently Asked Questions About poly(C) RNA binding
What is poly(C) RNA binding?
Poly(C) RNA binding is the molecular function defined by GO:0017130 as binding to a sequence of cytosine residues in an RNA molecule.
What is GO:0017130?
GO:0017130 is the Gene Ontology identifier for poly(C) RNA binding, a molecular_function term.
What genes are involved in poly(C) RNA binding?
Genes encoding poly(C)-binding proteins such as PCBP1 and related KH-domain proteins are involved, and RNA-sensing genes such as ZNFX1 and GBP1 are relevant to poly(I:C)-related responses.
Which proteins bind poly(C) RNA?
The poly(C)-binding proteins (PCBPs) are the principal known poly(C) RNA-binding proteins, and their KH domains mediate RNA recognition.
How is poly(C) RNA binding measured?
It can be measured by RNA pull-down, electrophoretic mobility shift assays and RNA immunoprecipitation, as illustrated by KH-domain RNA-binding studies.
What is the role of KH domains in poly(C) RNA binding?
KH domains are RNA-binding modules, and the third KH domain of PCBP1 has been structurally and biochemically characterized for RNA binding.
Is poly(C) RNA binding involved in disease?
It is linked to neurofilament mRNA stability and to antiviral and inflammatory RNA-sensing pathways relevant to disease research.
How does poly(I:C) relate to poly(C) RNA binding?
Poly(I:C) is a synthetic RNA ligand used to trigger antiviral and inflammatory responses, and proteins such as ZNFX1 and GBP1 modulate these responses.
Can CRISPR be used to study poly(C) RNA binding?
Yes, CRISPR knockout, point mutation, knock-in and overexpression models can test the function of genes encoding poly(C) RNA-binding proteins.
What cell models are used for poly(C) RNA binding research?
Knockout, point-mutation, knock-in and overexpression cell models, as well as CRISPR library screening, are suitable for studying poly(C) RNA binding.
Conclusion
GO:0017130 poly(C) RNA binding defines a sequence-selective RNA-binding function executed by poly(C)-binding proteins and related KH-domain factors. Its biological importance spans mRNA stability control, including neurofilament mRNAs, and antiviral or inflammatory RNA-sensing pathways involving poly(I:C) and proteins such as ZNFX1 and GBP1. Cancer models using poly(I:C) RNA complexes further illustrate its translational potential. CRISPR-based knockout, point-mutation, knock-in and overexpression models provide a rigorous path to establish causality for genes involved in poly(C) RNA binding.
References
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- 4. Ramani M et al.. 2017. Zinc Oxide Nanoparticle-Poly I:C RNA Complexes: Implication as Therapeutics against Experimental Melanoma.. Mol Pharm 14(3):614-625 PMID: 28135100
- 5. Kumar R et al.. 2025. Guanylate binding protein1 alters expression of the poly I: C induced cytokines/chemokines and MAP kinases in macrophages.. Hum Immunol 86(1):111211 PMID: 39642778
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