GO:0070390 transcription export complex 2: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070390 transcription export complex 2 (TREX-2) is a nuclear pore-associated protein complex that couples SAGA-dependent transcription to mRNA export.
• In S. cerevisiae, TREX-2 contains Sac3p, Thp1p, Sem1, Sus1p and Cdc31p, and is tethered to the inner side of the nuclear pore complex via Nup1 and Nup60.
• The human TREX-2 complex, including GANP and ENY2, is essential for mRNA export and is linked to transcription-coupled DNA damage and carcinogenesis.
• TREX-2 is hijacked by viruses such as influenza to export viral mRNAs, making it a host-factor target.
• Sus1 maintains normal lifespan through regulation of TREX-2-mediated mRNA export, connecting the complex to aging biology.
• CRISPR knockout, point mutation, knock-in and overexpression models are key tools for dissecting TREX-2 gene function in disease and development.
Description
The transcription export complex 2 (TREX-2), annotated as GO:0070390, is a cellular component that physically and functionally couples SAGA-dependent gene expression to mRNA export at the inner side of the nuclear pore complex (NPC). This coupling ensures that newly synthesized transcripts are efficiently recognized, packaged and exported to the cytoplasm, a process essential for gene expression fidelity. TREX-2 is conserved from yeast to humans, where its subunits include Sac3p/ganp, Thp1p, Sem1, Sus1p/ENY2 and Cdc31p in S. cerevisiae. In humans, the complex is increasingly recognized as a hub for mRNA export regulation and a contributor to transcription-coupled DNA damage and carcinogenesis. Because TREX-2 sits at the interface of transcription and nuclear export, it is a focal point for understanding how cells coordinate gene expression with nuclear architecture. Researchers study GO:0070390 to uncover mechanisms of mRNA biogenesis, viral mRNA export and disease-associated genome instability.
transcription export complex 2 At A Glance
| GO ID | GO:0070390 |
|---|---|
| GO term | transcription export complex 2 |
| Ontology | cellular_component |
| Synonym | Sac3-Thp1-Sus1-Sem1-Cdc31 complex; TREX-2 complex |
| Major function | Couples SAGA-dependent gene expression to mRNA export at the inner side of the nuclear pore complex |
| Subunit composition (S. cerevisiae) | Sac3p, Thp1p, Sem1, Sus1p, Cdc31p |
| Nuclear pore tethering | Nup1 and Nup60 at the inner side of the NPC |
| Conservation | Conserved from yeast to humans; human complex includes GANP and ENY2 |
| Disease relevance | Transcription-coupled DNA damage, carcinogenesis, viral mRNA export |
What Is GO:0070390?
GO:0070390 transcription export complex 2 is defined as a protein complex that couples SAGA-dependent gene expression to mRNA export at the inner side of the nuclear pore complex (NPC). The TREX-2 complex is tethered to the inner side of the NPC via the nucleoporins Nup1 and Nup60; in S. cerevisiae it contains Sac3p, Thp1p, Sem1, Sus1p and Cdc31p. Synonyms include the Sac3-Thp1-Sus1-Sem1-Cdc31 complex and TREX-2 complex.
Why Is transcription export complex 2 Important in Cell Biology?
GO:0070390 transcription export complex 2 is important because it provides a physical and functional link between transcription and mRNA export, ensuring that transcripts are correctly processed and delivered to the cytoplasm. Disruption of TREX-2 function leads to mRNA export defects, transcription-coupled DNA damage and genome instability, which are hallmarks of cancer and aging. The complex is also exploited by pathogens such as influenza virus to export viral mRNAs, highlighting its role in host-pathogen interactions. Understanding TREX-2 therefore has broad implications for gene regulation, disease mechanisms and antiviral strategies.
• Couples SAGA-dependent transcription to mRNA export at the nuclear pore complex.
• Essential for efficient mRNA recognition and packaging during export.
• Loss of function causes transcription-coupled DNA damage and genome instability.
• Implicated in carcinogenesis through GANP and other TREX-2 components.
• Regulates lifespan and aging via Sus1-mediated mRNA export.
• Hijacked by influenza virus for nuclear export of viral mRNAs.
• Provides a model for studying nuclear pore complex-associated gene regulation.
• Target for antiviral and anticancer therapeutic development.
• Links mRNA export to spliceosome and transcription machinery dynamics.
• Conserved mechanism from yeast to humans enables cross-species research.
What Happens During transcription export complex 2?
Transcription-coupled recruitment to the nuclear pore
In simple terms: TREX-2 helps bring newly made mRNA from the gene to the nuclear pore for export.
TREX-2 is tethered to the inner side of the nuclear pore complex via the nucleoporins Nup1 and Nup60, positioning it to receive transcripts emerging from SAGA-dependent genes. This spatial coupling ensures that mRNA export is coordinated with transcription, a process that is conserved and essential for gene expression. In plants, the related THO/TREX complex contributes to transcription termination, underscoring the broader importance of coupling transcription to export.
mRNA recognition and packaging
In simple terms: TREX-2 recognizes mRNA and helps package it for safe transport out of the nucleus.
The human transcription-export complex recognizes and packages mRNA, a step required for efficient nuclear export. TREX-2, together with other export factors, ensures that only properly processed transcripts are exported, maintaining mRNA quality control. This recognition involves interactions with the mRNA and with other components of the export machinery, as revealed by structural and biochemical studies.
ATP-gated molecular switch and export regulation
In simple terms: An energy-dependent switch controls when mRNA is released for export.
An ATP-gated molecular switch orchestrates human mRNA export, regulating the dynamic assembly and disassembly of export complexes including TREX-2. This switch ensures that export is tightly controlled and responsive to cellular energy status. Molecular insights into human TREX-2 regulation have further clarified how the complex transitions between states to facilitate mRNA handover to the nuclear pore.
Viral subversion of TREX-2 for mRNA export
In simple terms: Some viruses use TREX-2 to export their own mRNA.
Influenza virus mRNAs encode determinants for nuclear export via the cellular TREX-2 complex, allowing the virus to hijack host export machinery. This highlights the central role of TREX-2 in mRNA export and its potential as an antiviral target. The viral strategy underscores the importance of TREX-2 in both normal and pathological contexts.
Key Genes Involved in GO:0070390 transcription export complex 2
The following genes and proteins are core components or regulators of the transcription export complex 2 (GO:0070390) and are frequently studied in functional and disease research.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SAC3 | Scaffold subunit of TREX-2 in S. cerevisiae | Model for complex assembly and mRNA export |
| THP1 | Component of TREX-2 involved in mRNA export | Studied for transcription-export coupling |
| SEM1 | Small subunit of TREX-2 and other complexes | Links TREX-2 to ubiquitin-like pathways |
| SUS1 | Transcriptional coactivator and TREX-2 subunit | Regulates lifespan and mRNA export |
| CDC31 | Calcium-binding protein in TREX-2 | Role in nuclear pore tethering |
| GANP | Human TREX-2 component, mRNA export factor | Implicated in carcinogenesis and DNA damage |
| ENY2 | Human Sus1 homolog, TREX-2 subunit | Studied in mRNA export and transcription |
| NUP1 | Nucleoporin tethering TREX-2 to NPC | Nuclear pore anchoring of TREX-2 |
| NUP60 | Nucleoporin tethering TREX-2 to NPC | Nuclear pore anchoring of TREX-2 |
| THO | Transcription-export complex subunit in plants | Transcription termination and export |
| TEX1 | THO/TREX component | mRNA export and genome stability |
| SAC3D1 | Human TREX-2 subunit | mRNA export regulation |
| PCID2 | Human TREX-2 subunit | mRNA export and DNA damage response |
| DSS1 | Human Sem1 homolog | TREX-2 assembly and stability |
| CETN2 | Human Cdc31 homolog | Centrosome and TREX-2 functions |
| SAGA | Transcription coactivator complex | Couples transcription to TREX-2 |
| NPC | Nuclear pore complex | Docking site for TREX-2 |
How Is transcription export complex 2 Regulated?
TREX-2 function is regulated by its dynamic interactions with the nuclear pore complex and by ATP-dependent switches that control mRNA export. The complex is also regulated through its subunit composition and post-translational modifications, as suggested by molecular insights into human TREX-2 regulation. Sus1, a TREX-2 subunit, maintains normal lifespan through regulation of TREX-2-mediated mRNA export, indicating that the complex is subject to aging-related regulation. Viral factors can also modulate TREX-2 activity by encoding determinants that recruit the complex for viral mRNA export.
transcription export complex 2 and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| GANP | Carcinogenesis, transcription-coupled DNA damage | Knockout and point mutation in cancer cell lines |
| SUS1 | Aging and lifespan regulation | Overexpression and knockout in yeast or human cells |
| ENY2 | mRNA export defects, cancer | Knockdown and rescue in human cell lines |
| SAC3 | mRNA export and genome stability | Yeast knockout and knock-in models |
| THP1 | Transcription-export coupling | CRISPR knockout in plant or yeast models |
Cancer and genome instability
Carcinogenesis caused by transcription-coupled DNA damage through GANP and other components of the TREX-2 complex has been documented, linking TREX-2 dysfunction to genome instability and cancer. Loss of TREX-2 function can lead to accumulation of DNA damage during transcription, promoting oncogenic transformation. This makes TREX-2 genes potential targets for cancer research and therapeutic intervention.
Aging and lifespan regulation
Sus1 maintains a normal lifespan through regulation of TREX-2 complex-mediated mRNA export, connecting TREX-2 to aging biology. Dysregulation of mRNA export via TREX-2 may contribute to age-related cellular decline. This suggests that TREX-2 components could be studied as modulators of longevity.
Viral infection and host-pathogen interactions
Influenza virus mRNAs encode determinants for nuclear export via the cellular TREX-2 complex, demonstrating that TREX-2 is exploited by viruses. Targeting TREX-2 or its interactions with viral factors could provide antiviral strategies. This highlights the importance of TREX-2 in infectious disease research.
From transcription export complex 2-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of TREX-2 cause mRNA export defects? | CRISPR knockout of GANP or ENY2 in human cells |
| How does Sus1 regulate lifespan? | Overexpression and knockout of SUS1 in yeast |
| What is the role of Nup1/Nup60 tethering? | Point mutations in NUP1/NUP60 in S. cerevisiae |
| How does influenza hijack TREX-2? | Viral infection with TREX-2 knockout cells |
| What is the structural basis of TREX-2 assembly? | Tagged knock-in for affinity purification and cryo-EM |
| Does TREX-2 mutation affect transcription termination? | Knockout of THO/TREX components in plants |
How to Study the transcription export complex 2 Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Global transcript levels and export defects | Assessing TREX-2 knockout effects |
| Subcellular fractionation | Nuclear vs cytoplasmic mRNA distribution | Validating mRNA export function |
| Affinity purification-mass spectrometry | Protein-protein interactions and complex composition | Defining TREX-2 subunits |
| Fluorescence microscopy | Subcellular localization at nuclear pore | Confirming NPC tethering |
| Cryo-EM | 3D structure of TREX-2 and mRNA complexes | Understanding mRNA recognition |
| Yeast genetics | Growth and export phenotypes | Functional studies in S. cerevisiae |
| Viral infection assays | Viral mRNA export efficiency | Studying host-pathogen interactions |
| Lifespan assays | Replicative lifespan in yeast | Linking TREX-2 to aging |
RNA-seq and export assays
RNA-seq and subcellular fractionation can measure mRNA export defects upon TREX-2 perturbation, revealing changes in nuclear versus cytoplasmic transcript levels. These methods are used to assess the impact of TREX-2 loss on global gene expression.
Proteomics and interactomics
Affinity purification coupled with mass spectrometry identifies TREX-2 subunits and interacting partners, including nucleoporins and SAGA components. Proteomic approaches have been used to define the human TREX-2 complex composition.
Imaging and nuclear pore localization
Fluorescence microscopy and live-cell imaging can visualize TREX-2 localization at the nuclear pore complex and track mRNA export dynamics. These methods help confirm tethering via Nup1 and Nup60.
Structural biology
Cryo-electron microscopy and X-ray crystallography provide molecular insights into TREX-2 architecture and its regulation. Structural studies have revealed how the complex recognizes mRNA and interacts with the nuclear pore.
How CRISPR Can Be Used to Study GO:0070390 transcription export complex 2
Knockout
CRISPR knockout of TREX-2 genes such as GANP or ENY2 in human cell lines can reveal their essential roles in mRNA export and cell viability. Knockout models are used to study transcription-coupled DNA damage and genome instability.
Point Mutation
Point mutations in TREX-2 subunits or in the nucleoporins Nup1 and Nup60 can dissect specific interaction interfaces required for nuclear pore tethering and mRNA export. Such models help separate export functions from other roles of the complex.
Knock-in
Tagged knock-in of TREX-2 subunits enables affinity purification, imaging and proteomic studies to define complex composition and dynamics. Knock-in of disease-associated mutations can model human pathologies.
Overexpression
Overexpression of TREX-2 components such as Sus1 can be used to study lifespan regulation and mRNA export efficiency. Overexpression models also help identify dominant-negative or gain-of-function effects.
How EDITGENE Supports transcription export complex 2 Research
Researchers studying transcription export complex 2-related genes often need to determine whether a candidate gene is causally involved in mRNA export, genome stability or disease. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models for such functional studies.
Contact EDITGENE today to design your custom CRISPR model for transcription export complex 2 research.
Frequently Asked Questions About transcription export complex 2
What is transcription export complex 2 (GO:0070390)?
It is a protein complex that couples SAGA-dependent gene expression to mRNA export at the inner side of the nuclear pore complex, containing Sac3p, Thp1p, Sem1, Sus1p and Cdc31p in S. cerevisiae.
What genes are involved in transcription export complex 2?
Core genes include SAC3, THP1, SEM1, SUS1 and CDC31 in yeast, and GANP, ENY2, SAC3D1, PCID2, DSS1 and CETN2 in humans.
Where is TREX-2 located in the cell?
TREX-2 is located at the inner side of the nuclear pore complex, tethered via the nucleoporins Nup1 and Nup60.
What is the function of TREX-2 in mRNA export?
TREX-2 couples transcription to mRNA export, ensuring that newly synthesized transcripts are recognized, packaged and exported to the cytoplasm.
How is TREX-2 linked to cancer?
GANP and other TREX-2 components are implicated in transcription-coupled DNA damage and carcinogenesis, contributing to genome instability.
Does TREX-2 play a role in aging?
Yes, Sus1 maintains a normal lifespan through regulation of TREX-2 complex-mediated mRNA export.
Can viruses use TREX-2 for their own mRNA export?
Influenza virus mRNAs encode determinants for nuclear export via the cellular TREX-2 complex, allowing the virus to hijack the host machinery.
What methods are used to study TREX-2?
Common methods include RNA-seq, subcellular fractionation, affinity purification-mass spectrometry, fluorescence microscopy and cryo-EM.
What CRISPR models are available for TREX-2 research?
Knockout, point mutation, knock-in, tagged knock-in and overexpression models can be generated for TREX-2 genes to study function and disease.
Is TREX-2 conserved across species?
Yes, TREX-2 is conserved from yeast to humans, with homologous subunits and functions.
Conclusion
GO:0070390 transcription export complex 2 is a central node coupling transcription to mRNA export at the nuclear pore complex, with essential roles in gene expression, genome stability and disease. Its conservation and involvement in cancer, aging and viral infection make it a high-value target for functional studies. CRISPR-based models and advanced omics approaches will continue to illuminate its mechanisms and therapeutic potential.
References
- 1. Pacheco-Fiallos B et al.. 2023. mRNA recognition and packaging by the human transcription-export complex.. Nature 616(7958):828-835 PMID: 37020021
- 2. Matera AG et al.. 2014. A day in the life of the spliceosome.. Nat Rev Mol Cell Biol 15(2):108-21 PMID: 24452469
- 3. Khan GA et al.. 2020. The transcription and export complex THO/TREX contributes to transcription termination in plants.. PLoS Genet 16(4):e1008732 PMID: 32282821
- 4. Gong X et al.. 2026. Molecular insights into mRNA export regulation by the human TREX-2 complex.. Nat Commun 17(1) PMID: 41748650
- 5. Sakai Y et al.. 2024. Carcinogenesis caused by transcription-coupled DNA damage through GANP and other components of the TREX-2 complex.. Pathol Int 74(3):103-118 PMID: 38411330
- 6. Hohmann U et al.. 2026. An ATP-gated molecular switch orchestrates human mRNA export.. Nature 649(8098):1042-1050 PMID: 41198879
- 7. Lim S et al.. 2022. Sus1 maintains a normal lifespan through regulation of TREX-2 complex-mediated mRNA export.. Aging (Albany NY) 14(12):4990-5012 PMID: 35771153
- 8. Bhat P et al.. 2023. Influenza virus mRNAs encode determinants for nuclear export via the cellular TREX-2 complex.. Nat Commun 14(1):2304 PMID: 37085480
