GO:0062141 nuclear exosome targeting complex: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0062141 (nuclear exosome targeting complex, NEXT) is a nuclear protein complex that works with the RNA exosome to degrade aberrant transcripts.
• The human NEXT complex is built around the scaffold protein ZCCHC8, the RNA helicase MTR4, and the RNA-binding adaptor RBM7.
• NEXT is recruited to RNA polymerase II and helps prevent transcription-replication conflicts, a function linked to the MYCN oncoprotein.
• NEXT safeguards hematopoietic stem cell self-renewal and genomic integrity by resolving R loops.
• Loss or dysregulation of NEXT components is being explored in cancer, autoimmunity, and stem cell biology.
• CRISPR knockout, point mutation, knock-in, and overexpression models are key tools for dissecting NEXT function in disease.
Description
The nuclear exosome targeting complex (NEXT) is a conserved nuclear protein complex that functions together with the RNA exosome to degrade aberrant transcripts. It is annotated in the Gene Ontology as GO:0062141, a cellular component term defined as a protein-containing complex that functions with the RNA exosome and contributes to the degradation of aberrant transcripts. NEXT is essential for RNA quality control in the nucleus, where it recognizes and targets defective or unwanted RNAs for destruction. Understanding NEXT is important because its dysfunction has been linked to cancer progression, genomic instability, and impaired stem cell function. The complex also interacts with RNA polymerase II and transcription-associated factors, placing it at the interface of transcription and RNA surveillance. This article summarizes the current understanding of NEXT structure, composition, regulation, and its roles in disease, based strictly on published literature.
nuclear exosome targeting complex At A Glance
| GO ID | GO:0062141 |
|---|---|
| GO term | nuclear exosome targeting complex |
| Ontology | cellular_component |
| Synonym | NEXT complex |
| Major function | Functions with the RNA exosome to degrade aberrant transcripts |
| Key components | ZCCHC8, MTR4, RBM7 |
| Associated factors | MYCN, RNA polymerase II |
| Biological context | Nuclear RNA surveillance, transcription-replication conflict resolution, R-loop resolution |
What Is GO:0062141?
GO:0062141, nuclear exosome targeting complex, is a protein-containing complex that functions with the RNA exosome and contributes to the degradation of aberrant transcripts. In simpler terms, it is a molecular machine that helps the cell identify and destroy faulty RNA molecules in the nucleus.
Why Is nuclear exosome targeting complex Important in Cell Biology?
The nuclear exosome targeting complex is critical for maintaining nuclear RNA quality control and genomic stability. By targeting aberrant transcripts for degradation, NEXT prevents the accumulation of defective RNAs that could otherwise interfere with normal cellular processes. Its interaction with MYCN and RNA polymerase II links it to transcription regulation and cancer biology. Furthermore, NEXT is required for hematopoietic stem cell self-renewal and genomic integrity through its role in resolving R loops. These functions make NEXT a subject of intense research interest in cancer, stem cell biology, and RNA metabolism.
• Maintains nuclear RNA quality control by degrading aberrant transcripts.
• Prevents transcription-replication conflicts by recruiting the exosome to RNA polymerase II.
• Supports hematopoietic stem cell self-renewal and genomic integrity via R-loop resolution.
• Interacts with the MYCN oncoprotein, linking it to cancer progression.
• Its dysfunction may contribute to genomic instability and disease.
• Serves as a model for studying RNA exosome targeting mechanisms.
• Relevant to autoimmunity, as autoantibodies against related complexes are found in myositis.
• Provides potential targets for therapeutic intervention in cancers with MYCN amplification.
• Essential for understanding RNA surveillance in normal development and disease.
• Offers a paradigm for how adaptor complexes confer substrate specificity to the exosome.
Structure and Composition of nuclear exosome targeting complex
Core scaffold: ZCCHC8
In simple terms: ZCCHC8 acts as the central organizer that holds the NEXT complex together.
ZCCHC8 is a scaffold protein that forms the structural core of the human NEXT complex. Structural studies have revealed that ZCCHC8 provides a platform for assembling the other subunits and for interacting with the RNA exosome. It contains a zinc knuckle domain that contributes to RNA binding and complex stability.
RNA helicase: MTR4
In simple terms: MTR4 is a molecular motor that unwinds RNA to help feed it into the exosome.
MTR4 (also known as SKIV2L2) is an RNA helicase that is part of the NEXT complex. It uses ATP to unwind RNA structures and facilitate the transfer of RNA substrates to the exosome for degradation. MTR4 is conserved from yeast to humans and is essential for NEXT function.
RNA-binding adaptor: RBM7
In simple terms: RBM7 recognizes and binds to the aberrant RNAs that need to be destroyed.
RBM7 is an RNA-binding protein that helps NEXT recognize its targets. It contains an RNA recognition motif (RRM) that binds to specific sequences or structures in aberrant transcripts, thereby recruiting the complex to its substrates. RBM7 is thought to be important for substrate specificity.
Interaction with the RNA exosome
In simple terms: NEXT hands off faulty RNAs to the exosome, which chews them up.
The NEXT complex directly interacts with the RNA exosome, a multi-subunit complex with 3' to 5' exoribonuclease activity. Structural and biochemical studies have shown that NEXT delivers RNA substrates to the exosome for degradation. This interaction is mediated by ZCCHC8 and possibly other subunits.
Association with MYCN and RNA polymerase II
In simple terms: NEXT can team up with MYCN and the transcription machinery to keep RNA production safe.
The MYCN oncoprotein has been identified as an RNA-binding accessory factor of the NEXT complex. MYCN recruits the nuclear exosome complex to RNA polymerase II to prevent transcription-replication conflicts. This association links NEXT to transcription regulation and cancer.
Key Genes Involved in GO:0062141 nuclear exosome targeting complex
The following genes encode the major protein components and associated factors of the nuclear exosome targeting complex.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ZCCHC8 | Scaffold protein of NEXT | Structural core; knockout disrupts complex assembly |
| MTR4 | RNA helicase; unwinds RNA for exosome | Essential for RNA transfer to exosome |
| RBM7 | RNA-binding adaptor; substrate recognition | Determines target specificity |
| MYCN | RNA-binding accessory factor; recruits exosome to RNA Pol II | Oncogene; linked to cancer and transcription-replication conflicts |
| EXOSC1 | Exosome subunit | Core exosome component |
| EXOSC2 | Exosome subunit | Core exosome component |
| EXOSC3 | Exosome subunit | Core exosome component |
| EXOSC4 | Exosome subunit | Core exosome component |
| EXOSC5 | Exosome subunit | Core exosome component |
| EXOSC6 | Exosome subunit | Core exosome component |
| EXOSC7 | Exosome subunit | Core exosome component |
| EXOSC8 | Exosome subunit | Core exosome component |
| EXOSC9 | Exosome subunit | Core exosome component |
| EXOSC10 | Exosome subunit | Core exosome component |
| DIS3 | Exosome catalytic subunit | Exoribonuclease activity |
| POLR2A | RNA polymerase II largest subunit | Transcription; interacts with NEXT via MYCN |
How Is nuclear exosome targeting complex Regulated?
The nuclear exosome targeting complex is regulated at multiple levels. Its association with MYCN suggests that oncogenic signals can influence NEXT activity. MYCN recruits the exosome to RNA polymerase II, linking NEXT function to transcription and cell cycle progression. Additionally, NEXT activity is required for resolving R loops during hematopoietic stem cell self-renewal, indicating that its function is integrated with genome maintenance pathways. However, the precise molecular mechanisms controlling NEXT assembly and activity remain an active area of research.
nuclear exosome targeting complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| MYCN | Cancer (e.g., neuroblastoma) | MYCN-amplified cell lines; knockout or overexpression |
| ZCCHC8 | Genomic instability; stem cell dysfunction | ZCCHC8 knockout hematopoietic stem cells |
| MTR4 | RNA processing defects | MTR4 knockout cell lines |
| RBM7 | Aberrant RNA accumulation | RBM7 knockout cell lines |
| EXOSC3 | Pontocerebellar hypoplasia | Patient-derived fibroblasts; CRISPR knock-in |
Cancer
The MYCN oncoprotein acts as an RNA-binding accessory factor of the NEXT complex, and this interaction is implicated in cancer progression. MYCN recruits the nuclear exosome to RNA polymerase II to prevent transcription-replication conflicts, a process that may support the rapid proliferation of cancer cells. Dysregulation of NEXT components could therefore contribute to oncogenesis, particularly in MYCN-amplified tumors.
Hematopoietic stem cell biology and genomic integrity
The nuclear exosome targeting complex safeguards hematopoietic stem cell self-renewal and genomic integrity through resolving R loops. Loss of NEXT function may lead to R-loop accumulation, DNA damage, and impaired stem cell function, highlighting its importance in tissue homeostasis.
Autoimmune myositis
Autoantibodies against nuclear exosome components have been observed in patients with myositis, suggesting that dysregulation of RNA surveillance pathways may contribute to autoimmunity. Although direct links to NEXT specifically are not yet established, the shared exosome machinery warrants further investigation.
From nuclear exosome targeting complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the effect of NEXT loss on RNA stability? | CRISPR knockout of ZCCHC8, MTR4, or RBM7 in cell lines |
| How does MYCN interact with NEXT? | Knock-in of tagged MYCN or NEXT subunits for proteomics |
| Does NEXT resolve R loops in stem cells? | Conditional knockout of Zcchc8 in mouse hematopoietic stem cells |
| What is the structural basis of NEXT assembly? | Recombinant expression and cryo-EM of NEXT components |
| Can NEXT mutations cause disease? | Point mutation knock-in in patient-derived iPSCs |
| How does NEXT regulate transcription? | Overexpression of NEXT subunits followed by RNA-seq and ChIP-seq |
How to Study the nuclear exosome targeting complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RIP-seq | RNA targets bound by NEXT | Identify aberrant transcripts |
| Mass spectrometry | Protein-protein interactions | Map NEXT interactome |
| Cryo-EM | 3D structure of NEXT | Understand RNA recognition |
| RNA-seq | Transcriptome changes upon NEXT loss | Assess RNA surveillance defects |
| CRISPR knockout screens | Genes required for cell fitness | Find synthetic lethal partners |
| ChIP-seq | Chromatin binding of RNA Pol II | Study transcription-replication conflicts |
| R-loop detection (DRIP-seq) | R-loop accumulation | Assess genomic instability |
| Proximity ligation assay | In situ protein interactions | Visualize NEXT-exosome association |
RNA immunoprecipitation and sequencing (RIP-seq)
RIP-seq can identify RNAs bound by NEXT components such as RBM7 or ZCCHC8. This method reveals the repertoire of aberrant transcripts targeted by the complex.
Proteomics and interactomics
Affinity purification coupled with mass spectrometry can define the protein interaction network of NEXT, including its association with MYCN and the exosome.
Structural biology (cryo-EM)
Cryo-electron microscopy has been used to solve the structure of the human NEXT complex, providing insights into how it recognizes and delivers RNA substrates.
Genome-wide CRISPR screens
CRISPR knockout screens can identify genes that are synthetic lethal with NEXT loss or that modulate its function in cancer and stem cells.
How CRISPR Can Be Used to Study GO:0062141 nuclear exosome targeting complex
Knockout
CRISPR knockout of NEXT components such as ZCCHC8, MTR4, or RBM7 can abolish complex function and reveal its role in RNA degradation and cell viability. Knockout models are essential for studying loss-of-function phenotypes in cancer and stem cells.
Point Mutation
Point mutations can be introduced into NEXT genes to dissect specific domains required for RNA binding, helicase activity, or protein interactions. Such models help distinguish between structural and catalytic functions.
Knock-in
Knock-in of epitope tags (e.g., FLAG, HA) into endogenous NEXT genes allows for affinity purification and localization studies. Knock-in of disease-associated mutations can model their impact on complex assembly.
Overexpression
Overexpression of NEXT subunits or MYCN can be used to study gain-of-function effects, such as enhanced RNA degradation or transcription-replication conflict resolution. This approach is useful for identifying downstream targets and phenotypes.
How EDITGENE Supports nuclear exosome targeting complex Research
Researchers studying nuclear exosome targeting complex-related genes often need to determine whether a candidate gene is causally involved in RNA surveillance, cancer, or stem cell biology. CRISPR-based models provide a robust way to test gene function and validate therapeutic targets.
Contact EDITGENE today to design your custom CRISPR model for nuclear exosome targeting complex research.
Frequently Asked Questions About nuclear exosome targeting complex
What is the nuclear exosome targeting complex?
The nuclear exosome targeting complex (NEXT) is a protein complex that functions with the RNA exosome to degrade aberrant transcripts in the nucleus.
What genes are involved in the nuclear exosome targeting complex?
Key genes include ZCCHC8, MTR4, and RBM7, which form the core complex, as well as associated factors like MYCN.
What is the function of GO:0062141?
GO:0062141 describes the nuclear exosome targeting complex, which contributes to the degradation of aberrant transcripts by working with the RNA exosome.
How does the NEXT complex recognize RNA?
The RNA-binding protein RBM7 within NEXT recognizes and binds to aberrant transcripts, while MTR4 helicase unwinds RNA for degradation.
What diseases are associated with the nuclear exosome targeting complex?
NEXT has been linked to cancer, genomic instability, and hematopoietic stem cell dysfunction.
How can CRISPR be used to study the nuclear exosome targeting complex?
CRISPR knockout, point mutation, knock-in, and overexpression models allow researchers to dissect the function of NEXT components in cells and animal models.
What is the role of MYCN in the nuclear exosome targeting complex?
MYCN acts as an RNA-binding accessory factor of NEXT and recruits the exosome to RNA polymerase II to prevent transcription-replication conflicts.
What methods are used to study the nuclear exosome targeting complex?
Common methods include RIP-seq, mass spectrometry, cryo-EM, RNA-seq, and CRISPR screens.
Is the nuclear exosome targeting complex conserved?
Yes, the NEXT complex is conserved from yeast to humans, with core components like MTR4 and RBM7 having orthologs.
What happens when the nuclear exosome targeting complex is lost?
Loss of NEXT leads to accumulation of aberrant transcripts, R-loop formation, genomic instability, and impaired stem cell self-renewal.
Conclusion
The nuclear exosome targeting complex (GO:0062141) is a vital RNA surveillance machine that collaborates with the RNA exosome to eliminate aberrant transcripts. Its roles in transcription-replication conflict resolution, R-loop management, and stem cell maintenance underscore its importance in genomic stability and disease. Continued research using CRISPR-based models will further illuminate its mechanisms and therapeutic potential.
References
- 2. Papadopoulos D et al.. 2024. The MYCN oncoprotein is an RNA-binding accessory factor of the nuclear exosome targeting complex.. Mol Cell 84(11):2070-2086.e20 PMID: 38703770
- 3. Papadopoulos D et al.. 2022. MYCN recruits the nuclear exosome complex to RNA polymerase II to prevent transcription-replication conflicts.. Mol Cell 82(1):159-176.e12 PMID: 34847357
- 4. Pan Y et al.. 2025. Nuclear exosome targeting complex safeguards hematopoietic stem cell self-renewal and genomic integrity through resolving R loops.. Cell Rep 44(12):116650 PMID: 41353749
- 6. Puno MR et al.. 2022. Structural basis for RNA surveillance by the human nuclear exosome targeting (NEXT) complex.. Cell 185(12):2132-2147.e26 PMID: 35688134
- 8. Pinal-Fernandez I et al.. 2024. Pathological autoantibody internalisation in myositis.. Ann Rheum Dis 83(11):1549-1560 PMID: 38902010
