GO:0000175 3'-5'-RNA exonuclease activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0000175 (3'-5'-RNA exonuclease activity) describes the catalytic removal of mononucleotides from the free 3' end of an RNA molecule, a fundamental step in RNA turnover and quality control [2,4].
• The exosome complex provides the major 3'-5' exoribonuclease machinery in eukaryotes, and its function is conserved from plants to humans [2,4].
• 3'-5' exoribonucleases act in both general RNA decay and in specialized pathways such as flavivirus restriction, where ZFP36L1 and ZFP36L2 recruit the RNA exosome to viral RNA [3,5].
• The 3'->5' RNA helicase YTHDC2 couples ATP-dependent unwinding to 3'-5' exonucleolytic decay and is essential for the mammalian meiotic program [6,7].
• Pan2-Pan3 and Ccr4-Not complexes cooperate in 3'-5' deadenylation and decay, influencing cell growth on non-fermentable carbon sources.
• Dysregulation of 3'-5' exoribonuclease activity is linked to cancer metabolism, antiviral responses, and germline defects, making it a target for functional genomics [1,3,6].
Description
3'-5'-RNA exonuclease activity (GO:0000175) is a molecular function defined as the catalysis of the sequential cleavage of mononucleotides from a free 3' terminus of an RNA molecule. This activity is central to RNA quality control, maturation, and turnover, and it is carried out by a diverse set of enzymes including the eukaryotic exosome complex and its associated factors [2,4]. In plants, the exosome and 3'-5' RNA degradation pathways have been shown to be essential for processing and degrading a wide range of transcripts [2,4]. In metazoans, the same catalytic principle is deployed in antiviral defense, where zinc finger proteins such as ZFP36L1 and ZFP36L2 recruit 3'-5' exosome-mediated decay to restrict flavivirus infection [3,5]. The functional importance of this activity extends to germline development, where the 3'->5' RNA helicase YTHDC2 regulates m6A-containing transcripts and ensures a successful meiotic program [6,7]. More recently, 3'-5' exoribonuclease components have been implicated in cancer metabolism, with MYG1 driving glycolysis and colorectal cancer development through nuclear-mitochondrial collaboration. For researchers, GO:0000175 provides a precise annotation for interrogating RNA stability, decay intermediates, and the enzymes that shape the transcriptome.
3'-5'-RNA exonuclease activity At A Glance
| GO ID | GO:0000175 |
|---|---|
| GO term | 3'-5'-RNA exonuclease activity |
| Ontology | molecular_function |
| Synonym | 3'-5' exoribonuclease activity; 3'-5'-exoribonuclease activity |
| Definition | Catalysis of the sequential cleavage of mononucleotides from a free 3' terminus of an RNA molecule. |
| Major function | RNA degradation, processing, and quality control from the 3' end |
| Representative complexes | Exosome complex, Pan2-Pan3, Ccr4-Not |
| Cellular context | Nucleus and cytoplasm; often coupled to helicases and adaptors |
| Related activity | 3'-5' RNA helicase activity (e.g., YTHDC2) [6,7] |
What Is GO:0000175?
In our own words, GO:0000175 describes the enzymatic activity that trims or degrades RNA by removing one nucleotide at a time from the 3' end. The reaction proceeds processively or distributively from a free 3' hydroxyl terminus, releasing 5'-mononucleotides. This activity is distinct from 5'-3' exoribonucleases such as XRN1, although both can act on the same RNA substrates in different pathways [3,5]. The QuickGO definition emphasizes sequential cleavage from a free 3' terminus, which means the enzyme requires an accessible 3' end and does not require a specific sequence motif, though substrate specificity can be conferred by accessory proteins [2,4].
Why Is 3'-5'-RNA exonuclease activity Important in Cell Biology?
3'-5'-RNA exonuclease activity is important because it governs the lifetime and quality of essentially every RNA in the cell, from mRNA and non-coding RNA to viral RNA. The exosome and its cofactors are required for 3' end processing of stable RNAs and for the elimination of aberrant transcripts [2,4]. In antiviral immunity, ZFP36L1 and ZFP36L2 direct 3'-5' exosome decay to flavivirus RNA, showing that this activity is a direct effector of host defense [3,5]. In the germline, YTHDC2 uses 3'->5' helicase activity to regulate m6A transcripts and ensure fertility [6,7]. In cancer, MYG1 links 3'-5' RNA metabolism to glycolysis and colorectal cancer development. Thus, measuring and manipulating GO:0000175 is central to understanding gene regulation, infection, reproduction, and tumorigenesis.
• Controls RNA stability and turnover, thereby shaping transcriptome dynamics [2,4].
• Required for 3' end processing and quality control of many RNA species [2,4].
• Acts as an antiviral effector when recruited by ZFP36L1/ZFP36L2 to flavivirus RNA [3,5].
• Supports meiotic progression through YTHDC2-dependent regulation of m6A transcripts [6,7].
• Cooperates with deadenylation complexes such as Pan2-Pan3 and Ccr4-Not to modulate cell growth.
• Contributes to cancer metabolism and colorectal cancer development via MYG1.
• Provides a druggable node for antiviral and anticancer strategies [1,3].
• Serves as a functional annotation for CRISPR screens targeting RNA decay factors [2,4].
• Enables researchers to distinguish 3'-5' from 5'-3' decay pathways in mechanistic studies [3,5].
• Offers a readout for RNA quality control in stem cells, neurons, and immune cells [6,7].
Molecular Mechanism of 3'-5'-RNA exonuclease activity
Substrate recognition and 3' end accessibility
In simple terms: The enzyme needs to find the loose 3' end of an RNA before it can start chewing.
3'-5' exoribonucleases require a free 3' terminus, and access is often controlled by RNA structure, helicases, or adaptor proteins. In plants, the exosome and 3'-5' RNA degradation machinery recognize and process a broad range of transcripts, indicating that substrate selection is context-dependent [2,4]. The 3'->5' RNA helicase YTHDC2 can unwind structured RNA to expose 3' ends for decay, coupling helicase activity to exonucleolytic processing [6,7].
Catalytic cleavage cycle
In simple terms: The enzyme cuts off one nucleotide at a time from the 3' end.
The catalytic cycle involves a two-metal-ion mechanism in many exoribonucleases, where the 3' hydroxyl attacks the phosphodiester bond, releasing a 5'-mononucleotide and shortening the RNA by one unit. The exosome complex provides the principal 3'-5' exoribonuclease activity in eukaryotes and is conserved in plants and animals [2,4]. Processivity and rate can be modulated by associated factors such as Pan2-Pan3 and Ccr4-Not, which influence deadenylation and decay.
Coupling to deadenylation and decay complexes
In simple terms: Other proteins help the exonuclease by first shortening the poly(A) tail.
Pan2-Pan3 and Ccr4-Not complexes cooperate in 3'-5' deadenylation, and this cooperation has a role in cell growth on non-fermentable carbon sources. This coupling ensures that 3'-5' exoribonuclease activity is not random but is integrated into regulated mRNA decay pathways. In antiviral responses, ZFP36L1 and ZFP36L2 recruit the RNA exosome to viral RNA, linking adaptor-mediated targeting to 3'-5' decay [3,5].
Regulation by helicases and m6A readers
In simple terms: Helicases and m6A reader proteins can decide which RNAs get degraded.
YTHDC2 is a 3'->5' RNA helicase that regulates m6A transcripts and is essential for a successful meiotic program in the mammalian germline. Its XRN1-regulated RNA helicase activity ensures mouse fertility independently of m6A recognition, showing that helicase and exonuclease functions can be uncoupled. These findings place 3'-5' exoribonuclease activity within a network of RNA modifications and helicases [6,7].
Nuclear-mitochondrial coordination
In simple terms: RNA decay factors can also influence how cells use energy.
MYG1 drives glycolysis and colorectal cancer development through nuclear-mitochondrial collaboration, implicating 3'-5' RNA metabolism in metabolic reprogramming. This suggests that 3'-5' exoribonuclease-related pathways can influence mitochondrial function and cancer cell metabolism. Such coordination expands the biological scope of GO:0000175 beyond canonical RNA decay.
Key Genes Involved in GO:0000175 3'-5'-RNA exonuclease activity
The following genes and proteins are experimentally linked to 3'-5'-RNA exonuclease activity or its regulation, based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| EXOSC family | Core subunits of the exosome complex | Provides the main 3'-5' exoribonuclease activity in eukaryotes [2,4] |
| DIS3 | Catalytic subunit of the exosome | Directly executes 3'-5' RNA degradation [2,4] |
| ZFP36L1 | Recruits exosome to viral RNA | Antiviral 3'-5' decay of flavivirus RNA |
| ZFP36L2 | Recruits exosome to viral RNA | Antiviral 3'-5' decay of flavivirus RNA |
| YTHDC2 | 3'->5' RNA helicase | Regulates m6A transcripts in meiosis [6,7] |
| PAN2 | Deadenylase subunit | Cooperates with Ccr4-Not in 3'-5' decay |
| PAN3 | Deadenylase subunit | Cooperates with Ccr4-Not in 3'-5' decay |
| CCR4 | Deadenylase subunit | Role in cell growth on non-fermentable carbon sources |
| NOT1 | Scaffold of Ccr4-Not | Coordinates 3'-5' deadenylation |
| MYG1 | Nuclear-mitochondrial regulator | Drives glycolysis and colorectal cancer |
| XRN1 | 5'-3' exoribonuclease | Contrasts with 3'-5' pathways in antiviral studies [3,5] |
| EXOSC3 | Exosome subunit | Exosome function in RNA processing [2,4] |
| EXOSC9 | Exosome subunit | Exosome function in RNA processing [2,4] |
| RRP6 | Exosome-associated exonuclease | 3'-5' processing in plants and other eukaryotes [2,4] |
| RRP44 | Exosome-associated exonuclease | 3'-5' processing in plants and other eukaryotes [2,4] |
| MTR4 | RNA helicase adaptor | Facilitates exosome targeting [2,4] |
| ZCCHC8 | Exosome adaptor | Links exosome to specific transcripts [2,4] |
How Is 3'-5'-RNA exonuclease activity Regulated?
3'-5'-RNA exonuclease activity is regulated at multiple levels. Adaptor proteins such as ZFP36L1 and ZFP36L2 target the exosome to specific viral RNAs, thereby controlling substrate selection [3,5]. Deadenylation complexes Pan2-Pan3 and Ccr4-Not modulate the rate of 3'-5' decay and influence cell growth on non-fermentable carbon sources. Helicases such as YTHDC2 couple ATP-dependent unwinding to 3'-5' exonucleolytic processing and are regulated by XRN1 in the germline [6,7]. In cancer, MYG1 links 3'-5' RNA metabolism to glycolytic and mitochondrial programs, suggesting metabolic regulation of this activity. These layers ensure that 3'-5' exoribonuclease activity is not constitutive but responsive to cellular state and infection [1,3,5,6,7,8].
3'-5'-RNA exonuclease activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| MYG1 | Colorectal cancer and glycolysis | KO and overexpression in colorectal cancer cell lines |
| ZFP36L1 | Flavivirus infection | KO and overexpression in antiviral assays |
| ZFP36L2 | Flavivirus infection | KO and overexpression in antiviral assays |
| YTHDC2 | Germline development and fertility | KO and point-mutation in mouse models [6,7] |
| PAN2/PAN3 | Cell growth on non-fermentable carbon sources | KO in yeast or mammalian cells |
Cancer metabolism and colorectal cancer
MYG1 drives glycolysis and colorectal cancer development through nuclear-mitochondrial collaboration, linking 3'-5' RNA metabolism to tumor metabolism. This suggests that 3'-5' exoribonuclease-related pathways may be exploited by cancer cells to sustain growth. Targeting MYG1 or associated RNA decay factors could be a therapeutic strategy in colorectal cancer.
Antiviral defense and flavivirus infection
ZFP36L1 and ZFP36L2 inhibit flavivirus infection by recruiting both 5'-3' XRN1 and 3'-5' RNA-exosome decay pathways [3,5]. This demonstrates that 3'-5' exoribonuclease activity is a direct effector of host antiviral immunity [3,5]. Enhancing this pathway could be a strategy to restrict flavivirus replication [3,5].
Germline development and fertility
YTHDC2, a 3'->5' RNA helicase, regulates m6A transcripts and is essential for a successful meiotic program in the mammalian germline. Its XRN1-regulated helicase activity ensures mouse fertility independently of m6A recognition. Defects in this pathway can lead to germline failure and infertility [6,7].
Cell growth and metabolic adaptation
Pan2-Pan3 and Ccr4-Not complexes have a role in cell growth on non-fermentable carbon sources, linking 3'-5' deadenylation to metabolic adaptation. This suggests that 3'-5' exoribonuclease activity contributes to cellular responses to nutrient availability. Dysregulation may affect cell viability under metabolic stress.
From 3'-5'-RNA exonuclease activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does the gene have 3'-5' exoribonuclease activity? | KO and overexpression with RNA stability assays [2,4] |
| Is the catalytic residue required for antiviral defense? | Point mutation of catalytic residues in ZFP36L1/L2 [3,5] |
| Does the gene regulate m6A transcripts in meiosis? | Knock-in of tagged YTHDC2 and KO mouse models [6,7] |
| Does the gene affect cancer metabolism? | KO and overexpression of MYG1 in colorectal cancer cells |
| Does the gene cooperate with deadenylation complexes? | KO of PAN2/PAN3 and CCR4-NOT subunits |
| Can we map RNA decay intermediates? | Tagged knock-in of exosome subunits followed by RNA-seq [2,4] |
How to Study the 3'-5'-RNA exonuclease activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Transcript abundance and decay intermediates | Global analysis of 3'-5' decay [2,4] |
| Ribo-seq | Translation efficiency and ribosome occupancy | Meiotic and germline studies [6,7] |
| Proteomics | Protein interactions and complex composition | Exosome and deadenylase interactomes [2,4,8] |
| Fluorescent RNA reporters | Real-time RNA decay in cells | Antiviral pathway studies [3,5] |
| CRISPR KO screens | Gene requirement for RNA stability | Functional genomics of decay factors [2,4] |
| In vitro exonuclease assays | Catalytic activity and processivity | Enzyme mechanism studies [2,4] |
| m6A-seq | m6A modification status | YTHDC2-dependent regulation [6,7] |
| Polysome profiling | mRNA translation status | Metabolic and cancer studies |
RNA-seq and decay profiling
RNA-seq after transcriptional shutoff can measure the half-lives of transcripts and reveal 3' decay intermediates generated by 3'-5' exoribonuclease activity [2,4]. In antiviral studies, RNA-seq of flavivirus-infected cells with ZFP36L1 or ZFP36L2 KO shows changes in viral RNA stability [3,5]. In germline studies, RNA-seq of YTHDC2 mutants reveals m6A transcript dysregulation [6,7].
Ribo-seq and translatome analysis
Ribo-seq can determine whether 3'-5' decay affects translation efficiency and ribosome occupancy on specific transcripts [6,7]. This is particularly useful for meiosis-related genes regulated by YTHDC2 [6,7]. Combining Ribo-seq with RNA-seq distinguishes decay from transcription effects [6,7].
Proteomics and interactomics
Affinity purification of exosome subunits followed by mass spectrometry identifies cofactors and adaptors that regulate 3'-5' exoribonuclease activity [2,4]. Proteomics of Pan2-Pan3 and Ccr4-Not complexes can reveal interaction partners under different carbon sources. These approaches help build a mechanistic map of the decay machinery [2,4,8].
Imaging and reporter assays
Fluorescent RNA reporters can visualize 3'-5' decay in live cells and quantify the effects of ZFP36L1/L2 or exosome subunits [3,5]. Single-molecule imaging can track the processivity of exoribonucleases on individual RNA molecules [2,4]. These methods complement biochemical assays and provide spatial information [3,5].
How CRISPR Can Be Used to Study GO:0000175 3'-5'-RNA exonuclease activity
Knockout
CRISPR knockout of exosome subunits or adaptors such as ZFP36L1 and ZFP36L2 can reveal their requirement for 3'-5' RNA decay and antiviral defense [3,5]. KO of MYG1 in colorectal cancer cells can test its role in glycolysis and tumor development. KO of PAN2/PAN3 or CCR4-NOT subunits can assess growth on non-fermentable carbon sources.
Point Mutation
Point mutations in catalytic residues of exoribonucleases can separate enzymatic activity from scaffolding functions [2,4]. For ZFP36L1/L2, point mutations can test whether RNA binding or exosome recruitment is required for antiviral activity [3,5]. For YTHDC2, point mutations can uncouple helicase activity from m6A recognition [6,7].
Knock-in
Knock-in of epitope tags or fluorescent proteins into endogenous exosome subunits enables live-cell imaging and proteomics [2,4]. Tagged YTHDC2 knock-in can track its localization and interaction with m6A transcripts during meiosis [6,7]. Knock-in of reporters can quantify 3'-5' decay in specific cell types [3,5].
Overexpression
Overexpression of ZFP36L1 or ZFP36L2 can enhance 3'-5' exosome-mediated decay of flavivirus RNA and reduce infection [3,5]. Overexpression of MYG1 can drive glycolysis and colorectal cancer phenotypes. Overexpression of exosome subunits can be used to study dominant-negative or gain-of-function effects [2,4].
How EDITGENE Supports 3'-5'-RNA exonuclease activity Research
Researchers studying 3'-5'-RNA exonuclease activity-related genes often need to determine whether a candidate gene is causally involved in RNA decay, antiviral defense, or cancer metabolism. EDITGENE provides CRISPR-based cell models and screening services to interrogate GO:0000175 with precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for 3'-5'-RNA exonuclease activity research.
Frequently Asked Questions About 3'-5'-RNA exonuclease activity
What is 3'-5'-RNA exonuclease activity?
It is the enzymatic activity that removes mononucleotides sequentially from the free 3' end of an RNA molecule, annotated as GO:0000175 [2,4].
What genes are involved in 3'-5'-RNA exonuclease activity?
Key genes include exosome subunits such as EXOSC family members and DIS3, adaptors ZFP36L1 and ZFP36L2, the helicase YTHDC2, and deadenylases PAN2, PAN3, and CCR4 [2,3,4,5,6,7,8].
How is 3'-5'-RNA exonuclease activity different from 5'-3' decay?
3'-5' exoribonucleases degrade RNA from the 3' end, while 5'-3' exoribonucleases such as XRN1 degrade from the 5' end; both pathways can act on the same RNA [3,5].
What diseases are linked to 3'-5'-RNA exonuclease activity?
It has been linked to colorectal cancer through MYG1, flavivirus infection through ZFP36L1/L2, and germline defects through YTHDC2 [1,3,5,6,7].
How can I study 3'-5'-RNA exonuclease activity in the lab?
Common methods include RNA-seq, Ribo-seq, in vitro exonuclease assays, proteomics, and CRISPR knockout or overexpression models [1,2,3,4,5,6,7,8].
What is the role of the exosome in 3'-5' RNA degradation?
The exosome complex provides the major 3'-5' exoribonuclease activity in eukaryotes and is conserved in plants and animals [2,4].
Does YTHDC2 have 3'-5' exonuclease activity?
YTHDC2 is a 3'->5' RNA helicase that regulates m6A transcripts and is essential for meiosis, but its helicase activity can be uncoupled from m6A recognition [6,7].
How do ZFP36L1 and ZFP36L2 inhibit flavivirus infection?
They recruit both 5'-3' XRN1 and 3'-5' RNA-exosome decay pathways to viral RNA, restricting infection [3,5].
Can CRISPR be used to study 3'-5'-RNA exonuclease activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to dissect the function of exoribonucleases and their adaptors [1,2,3,4,5,6,7,8].
What is the GO ID for 3'-5'-RNA exonuclease activity?
The GO ID is GO:0000175, a molecular_function term in the Gene Ontology [2,4].
Conclusion
3'-5'-RNA exonuclease activity (GO:0000175) is a fundamental molecular function that shapes RNA fate from the 3' end. Its machinery, including the exosome, ZFP36L1/L2, YTHDC2, and deadenylases, is implicated in antiviral defense, germline development, cancer metabolism, and cell growth [1,2,3,4,5,6,7,8]. Understanding this activity requires integrating genetic, biochemical, and computational approaches. EDITGENE provides the CRISPR models and bioinformatics needed to interrogate GO:0000175 in health and disease.
References
- 1. Chen J et al.. 2024. MYG1 drives glycolysis and colorectal cancer development through nuclear-mitochondrial collaboration.. Nat Commun 15(1):4969 PMID: 38862489
- 2. Lange H et al.. 2011. The exosome and 3'-5' RNA degradation in plants.. Adv Exp Med Biol 702:50-62 PMID: 21713677
- 3. Lin RJ et al.. 2025. The zinc finger protein ZFP36L2 inhibits flavivirus infection via the 5'-3' XRN1-mediated RNA decay pathway in the replication complexes.. J Biomed Sci 32(1):27 PMID: 39972499
- 4. Lange H et al.. 2010. The exosome and 3'-5' RNA degradation in plants.. Adv Exp Med Biol 702:50-62 PMID: 21618874
- 5. Chiu H et al.. 2022. Zinc Finger Protein ZFP36L1 Inhibits Flavivirus Infection by both 5'-3' XRN1 and 3'-5' RNA-Exosome RNA Decay Pathways.. J Virol 96(1):e0166521 PMID: 34643435
- 6. Wojtas MN et al.. 2017. Regulation of m(6)A Transcripts by the 3'→5' RNA Helicase YTHDC2 Is Essential for a Successful Meiotic Program in the Mammalian Germline.. Mol Cell 68(2):374-387.e12 PMID: 29033321
- 7. 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
- 8. Fujii S et al.. 2021. Pan2-Pan3 complex, together with Ccr4-Not complex, has a role in the cell growth on non-fermentable carbon sources.. Biochem Biophys Res Commun 570:125-130 PMID: 34280615
