GO:0048026 positive regulation of mRNA splicing, via spliceosome: Activation Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0048026 describes any process that activates or increases the rate or extent of mRNA splicing via a spliceosomal mechanism.
• Positive regulation of splicing is achieved by RNA elements, trans-acting proteins, and phase-separated nuclear structures that recruit or stabilize the spliceosome.
• The stress kinase PKR can be activated by intragenic RNA elements to positively regulate splicing of cellular and viral mRNA.
• USP42 drives nuclear speckle mRNA splicing through dynamic phase separation, linking splicing activation to tumorigenesis.
• Dysregulation of spliceosome activation is implicated in retinal disease, orofaciodigital syndrome, and hepatocellular carcinoma.
• CRISPR knockout, point-mutation, knock-in, and overexpression models enable causal dissection of positive splicing regulators.
Description
GO:0048026, positive regulation of mRNA splicing, via spliceosome, is a biological process term that captures any event which activates or increases the rate or extent of mRNA splicing executed by the spliceosome. Pre-mRNA splicing is a fundamental step in eukaryotic gene expression, and its positive regulation ensures that the spliceosome is assembled, catalytically activated, and directed to the correct splice sites at the right time. Because splicing influences transcript diversity, mRNA stability, and translational output, positive regulators of this process are central to cellular responses to stress, growth signals, and viral infection. Mechanistically, positive regulation can be mediated by cis-acting intragenic RNA elements that activate the stress kinase PKR, which in turn enhances splicing of cellular and viral mRNA. It can also be driven by trans-acting factors such as USP42, which directs dynamic phase separation to nuclear speckles and promotes mRNA splicing. Transcription factors add another layer by controlling alternative splicing regulatory networks, thereby shaping which splicing events are favored in a given cell state. For researchers, GO:0048026 provides a precise annotation target for experiments that measure splicing activation rather than splicing per se. It is relevant to cancer biology, where spliceosome programs support oncogenic MYC signaling, to retinal disease linked to spliceosomal helicase regulation, and to developmental disorders caused by minor intron splicing defects. Understanding positive regulation of mRNA splicing therefore connects molecular mechanism to disease phenotypes and to therapeutic hypotheses.
positive regulation of mRNA splicing, via spliceosome At A Glance
| GO ID | GO:0048026 |
|---|---|
| GO term | positive regulation of mRNA splicing, via spliceosome |
| Ontology | biological_process |
| Definition | Any process that activates or increases the rate or extent of mRNA splicing via a spliceosomal mechanism. |
| Synonyms | activation of nuclear mRNA splicing, via spliceosome; positive regulation of pre-mRNA splicing; stimulation of nuclear mRNA splicing via U2-type spliceosome; upregulation of nuclear mRNA splicing, via spliceosome |
| Major function | Enhances spliceosome-mediated removal of introns and exon joining in mRNA precursors. |
| Regulatory inputs | Intragenic RNA elements, stress kinases, phase-separated nuclear speckles, and transcription factors. |
| Disease links | Cancer, retinal disease, orofaciodigital syndrome, and splicing-related developmental defects. |
What Is GO:0048026?
In our own words, GO:0048026 refers to any biological process that stimulates, activates, or upregulates the splicing of messenger RNA precursors through the spliceosome, the large ribonucleoprotein machine that removes introns and joins exons. It is not the splicing reaction itself but the positive control layer that increases how much splicing occurs or how efficiently it proceeds.
Why Is positive regulation of mRNA splicing, via spliceosome Important in Cell Biology?
Positive regulation of mRNA splicing, via spliceosome, is important because it determines the efficiency and timing of intron removal, directly affecting the proteome and cellular stress responses. When this regulation is perturbed, cells can accumulate mis-spliced transcripts, alter oncogenic programs, or fail to express critical ciliary and retinal proteins, as seen in hepatocellular carcinoma, retinal disease, and orofaciodigital syndrome.
• Controls the rate of spliceosome-mediated intron removal and exon joining.
• Links stress signaling, such as PKR activation, to mRNA splicing outcomes.
• Supports oncogenic MYC/spliceosome programs in hepatocellular carcinoma.
• Involves phase-separated nuclear speckles that concentrate splicing factors.
• Is modulated by transcription factors that shape alternative splicing networks.
• Mutations affecting spliceosomal regulation cause retinal disease.
• Defects in minor intron splicing regulation cause orofaciodigital syndrome.
• Provides mechanistic targets for therapeutic modulation of splicing.
• Enables researchers to distinguish splicing activation from basal splicing.
• Connects RNA regulatory elements to kinase-driven antiviral mechanisms.
What Happens During positive regulation of mRNA splicing, via spliceosome?
Recognition of activating RNA elements
In simple terms: Certain RNA sequences inside a gene act like switches that turn splicing up.
Positive regulation can begin when intragenic RNA elements are recognized and activate the stress kinase PKR, which then enhances splicing of cellular and viral mRNA. These cis-acting elements provide a sequence-specific layer of control that couples RNA structure to splicing activation.
Recruitment and activation of spliceosomal components
In simple terms: The cell gathers and switches on the splicing machinery.
Once activating signals are present, spliceosomal components are recruited and their activity is increased, raising the rate or extent of mRNA splicing via the spliceosome. Regulatory principles of spliceosomal helicases such as Brr2 illustrate how the catalytic core can be controlled, with links to retinal disease when this control is disrupted.
Phase separation and nuclear speckle organization
In simple terms: Splicing factors cluster into droplets to work more efficiently.
USP42 drives nuclear speckle mRNA splicing by directing dynamic phase separation, showing that positive regulation can operate through the formation of biomolecular condensates that concentrate splicing machinery and promote tumorigenesis.
Transcription factor control of splicing networks
In simple terms: Master regulators of gene expression also tune splicing up or down.
Transcription factors exert multilayered control over alternative splicing regulatory networks, meaning that positive regulation of splicing is integrated with transcriptional programs that define cell state.
Spliceosome program coupling to oncogenic signaling
In simple terms: In cancer, splicing activation can be wired to growth signals.
Intron retention of DDX39A driven by SNRPD2 defines a splicing axis that supports the oncogenic MYC/spliceosome program in hepatocellular carcinoma, illustrating how positive regulation of splicing can be co-opted by cancer cells.
Key Genes Involved in GO:0048026 positive regulation of mRNA splicing, via spliceosome
The following genes and proteins have been experimentally linked to positive regulation of mRNA splicing, via spliceosome, or to the spliceosomal machinery it controls.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PKR (EIF2AK2) | Stress kinase activated by intragenic RNA elements to enhance splicing of cellular and viral mRNA | Antiviral mechanism and RNA-element-driven splicing activation |
| USP42 | Drives nuclear speckle mRNA splicing via dynamic phase separation | Tumorigenesis and condensate biology |
| SNRPD2 | Spliceosomal component whose expression drives DDX39A intron retention | Oncogenic MYC/spliceosome program in hepatocellular carcinoma |
| DDX39A | RNA helicase subject to intron retention in a splicing axis | Splicing regulation in liver cancer |
| MYC | Oncogenic transcription factor coupled to spliceosome programs | Cancer splicing dependencies |
| Brr2 | Spliceosomal RNA helicase with regulatory principles | Retinal disease links |
| SCNM1 | Minor intron splicing factor | Orofaciodigital syndrome and ciliary defects |
| Transcription factors (general) | Multilayered control of alternative splicing networks | Cell-state-specific splicing regulation |
| Spliceosome (U2-type) | Catalyzes mRNA splicing that is positively regulated | Core machinery for GO:0048026 |
| Nuclear speckle components | Concentrate splicing factors for efficient splicing | Phase separation and splicing efficiency |
| AIM2 | Inflammaging and senescence context | Periodontitis-related splicing and inflammation |
| Spliceozyme (engineered) | Hairpin ribozyme-derived splicing tool | Synthetic splicing activation approaches |
| SR proteins (general) | Splicing regulatory proteins | Alternative splicing network control |
| hnRNP proteins (general) | Splicing regulatory proteins | Alternative splicing network control |
| U2 snRNP | Spliceosomal subunit for U2-type splicing | Target of positive regulation |
| PRP proteins (general) | Spliceosomal ATPases/helicases | Catalytic control of splicing |
How Is positive regulation of mRNA splicing, via spliceosome Regulated?
Positive regulation of mRNA splicing, via spliceosome, is itself regulated at multiple levels. Intragenic RNA elements can activate the stress kinase PKR, which then enhances splicing of cellular and viral mRNA, coupling RNA sequence to kinase signaling. USP42 controls nuclear speckle mRNA splicing through dynamic phase separation, so the physical state of splicing condensates regulates splicing output. Transcription factors impose multilayered control on alternative splicing regulatory networks, integrating splicing with transcriptional programs. In disease contexts, SNRPD2-driven intron retention of DDX39A supports an oncogenic MYC/spliceosome program, showing that splicing activation can be rewired by oncogenic signaling.
positive regulation of mRNA splicing, via spliceosome and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SNRPD2 / DDX39A | Hepatocellular carcinoma oncogenic MYC/spliceosome program | Knockout or knockdown in liver cancer cell lines followed by RNA-seq |
| USP42 | Tumorigenesis via nuclear speckle phase separation | Overexpression and phase-separation imaging in cancer cells |
| Brr2 | Retinal disease linked to spliceosomal helicase regulation | Point-mutation knock-in in retinal cell models |
| SCNM1 | Orofaciodigital syndrome with minor intron splicing defects | Knockout in ciliated cell models and splicing assays |
| AIM2 | Inflammaging in periodontitis | Knockout in gingival fibroblasts and senescence assays |
Cancer and oncogenic splicing programs
Positive regulation of mRNA splicing can be hijacked in cancer. Intron retention of DDX39A driven by SNRPD2 is a crucial splicing axis for the oncogenic MYC/spliceosome program in hepatocellular carcinoma. USP42 promotes tumorigenesis by driving nuclear speckle mRNA splicing via dynamic phase separation, linking splicing activation to cancer cell growth.
Retinal disease and spliceosomal helicase control
Novel regulatory principles of the spliceosomal Brr2 RNA helicase have been linked to retinal disease in humans, indicating that perturbed control of spliceosomal activity can cause tissue-specific pathology.
Developmental disorders and minor intron splicing
Mutations in SCNM1 cause orofaciodigital syndrome due to minor intron splicing defects affecting primary cilia, demonstrating that disrupted splicing regulation can produce developmental syndromes.
Inflammation and aging
AIM2-mediated senescence of gingival fibroblasts exacerbates inflammaging in periodontitis, providing a context where splicing-related and inflammatory programs intersect.
From positive regulation of mRNA splicing, via spliceosome-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is a candidate gene required for positive regulation of splicing? | CRISPR knockout cell line followed by RNA-seq |
| Does a specific residue control splicing activation? | Point-mutation knock-in cell line |
| Does a disease variant alter splicing regulation? | Knock-in of the patient variant and splicing reporter assays |
| Where does a splicing regulator localize? | Tagged knock-in with fluorescence imaging |
| Does increased dosage of a regulator enhance splicing? | Overexpression cell model with transcriptome readout |
| Does a splicing axis support oncogenic growth? | Knockout or overexpression in cancer cell lines with proliferation assays |
How to Study the positive regulation of mRNA splicing, via spliceosome Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Genome-wide splicing events and intron retention | Detecting splicing changes after knockout or overexpression |
| Fluorescence imaging | Nuclear speckle dynamics and phase separation | Visualizing splicing factor condensates |
| Splicing reporter assays | Efficiency of specific splicing events | Testing regulatory elements and synthetic spliceozymes |
| Biochemical helicase assays | Spliceosomal helicase activity | Dissecting Brr2 regulatory principles |
| Transcriptome network analysis | Transcription factor control of splicing networks | Mapping alternative splicing regulatory networks |
| Minor intron splicing assays | Splicing of minor introns | Studying SCNM1-related developmental defects |
| Senescence and inflammation assays | Cellular aging and inflammaging markers | Contextualizing splicing in periodontitis models |
| Oncogenic growth assays | Proliferation and transformation | Testing splicing dependencies in cancer cells |
RNA-seq and splicing analysis
RNA-seq enables genome-wide measurement of intron retention, exon inclusion, and splicing efficiency, which is essential for detecting changes in positive regulation of mRNA splicing. Comparing knockout and control cells reveals which splicing events depend on a candidate regulator.
Imaging of nuclear speckles and condensates
Fluorescence imaging of tagged splicing factors allows researchers to visualize nuclear speckle dynamics and phase separation, as shown for USP42-driven mRNA splicing.
Splicing reporter and ribozyme assays
Engineered systems such as a hairpin ribozyme-derived spliceozyme provide controlled platforms to study splicing chemistry and activation principles.
Genetic and biochemical dissection of spliceosomal helicases
Biochemical and genetic approaches have revealed novel regulatory principles of the spliceosomal Brr2 RNA helicase, offering a template for studying how spliceosomal activity is positively regulated.
How CRISPR Can Be Used to Study GO:0048026 positive regulation of mRNA splicing, via spliceosome
Knockout
CRISPR knockout of candidate regulators such as SNRPD2 or SCNM1 allows researchers to test whether a gene is required for positive regulation of mRNA splicing and to read out consequences by RNA-seq.
Point Mutation
Point-mutation models can be used to interrogate specific residues in spliceosomal helicases like Brr2, helping to separate catalytic activity from regulatory functions linked to retinal disease.
Knock-in
Knock-in of disease-associated variants, such as those in SCNM1, enables study of how specific mutations alter minor intron splicing and primary cilia biology.
Overexpression
Overexpression of regulators such as USP42 can reveal gain-of-function effects on nuclear speckle splicing and tumorigenesis, complementing loss-of-function approaches.
How EDITGENE Supports positive regulation of mRNA splicing, via spliceosome Research
Researchers studying positive regulation of mRNA splicing, via spliceosome-related genes often need to determine whether a candidate gene is causally involved in splicing activation, which requires precise genetic models that isolate loss-of-function, gain-of-function, and variant-specific effects.
Contact EDITGENE today to design your custom CRISPR model for positive regulation of mRNA splicing, via spliceosome research.
Frequently Asked Questions About positive regulation of mRNA splicing, via spliceosome
What is GO:0048026?
GO:0048026 is the Gene Ontology term for positive regulation of mRNA splicing, via spliceosome, meaning any process that activates or increases the rate or extent of spliceosomal mRNA splicing.
What does positive regulation of mRNA splicing, via spliceosome mean?
It means a cellular process enhances the spliceosome-mediated removal of introns and joining of exons in mRNA precursors.
What genes are involved in positive regulation of mRNA splicing, via spliceosome?
Genes and proteins implicated include PKR, USP42, SNRPD2, DDX39A, MYC, Brr2, and SCNM1, among others.
How is mRNA splicing positively regulated?
Positive regulation can occur through intragenic RNA elements activating PKR, through phase separation driven by USP42, and through transcription factor control of splicing networks.
Why is positive regulation of mRNA splicing important in cancer?
It can support oncogenic programs, such as the MYC/spliceosome axis in hepatocellular carcinoma and USP42-driven tumorigenesis.
Which diseases are linked to defective splicing regulation?
Retinal disease, orofaciodigital syndrome, hepatocellular carcinoma, and inflammaging in periodontitis have been linked to splicing regulatory defects.
What methods study positive regulation of mRNA splicing?
RNA-seq, fluorescence imaging, splicing reporter assays, biochemical helicase assays, and transcriptome network analysis are commonly used.
How can CRISPR help study GO:0048026?
CRISPR knockout, point mutation, knock-in, and overexpression models allow causal testing of whether a gene positively regulates splicing.
What is the role of PKR in splicing regulation?
PKR can be activated by intragenic RNA elements and then enhance splicing of cellular and viral mRNA as part of an antiviral mechanism.
What is the role of USP42 in splicing?
USP42 drives nuclear speckle mRNA splicing via dynamic phase separation and promotes tumorigenesis.
Conclusion
GO:0048026, positive regulation of mRNA splicing, via spliceosome, defines the activation layer that controls how efficiently the spliceosome processes mRNA precursors. Its mechanisms span RNA elements, stress kinases, phase-separated nuclear speckles, and transcription factor networks, with direct relevance to cancer, retinal disease, and developmental disorders. Because splicing activation is causally linked to disease, precise genetic models are essential. CRISPR knockout, point-mutation, knock-in, and overexpression approaches, combined with RNA-seq and imaging, provide the experimental toolkit needed to dissect positive regulation of mRNA splicing in health and disease.
References
- 1. Kaempfer R. 2023. Positive Regulation of Splicing of Cellular and Viral mRNA by Intragenic RNA Elements That Activate the Stress Kinase PKR, an Antiviral Mechanism.. Genes (Basel) 14(5) PMID: 37239334
- 2. Liu S et al.. 2021. USP42 drives nuclear speckle mRNA splicing via directing dynamic phase separation to promote tumorigenesis.. Cell Death Differ 28(8):2482-2498 PMID: 33731873
- 3. Zhu J et al.. 2023. A Hairpin Ribozyme Derived Spliceozyme.. Chembiochem 24(13):e202300204 PMID: 37184100
- 4. Chang C et al.. 2024. Intron Retention of DDX39A Driven by SNRPD2 is a Crucial Splicing Axis for Oncogenic MYC/Spliceosome Program in Hepatocellular Carcinoma.. Adv Sci (Weinh) 11(35):e2403387 PMID: 39018261
- 5. Hao C et al.. 2026. AIM2-mediated senescence of gingival fibroblasts exacerbates inflammaging in periodontitis.. Free Radic Biol Med 245:71-83 PMID: 41456811
- 6. Mozaffari-Jovin S et al.. 2014. Novel regulatory principles of the spliceosomal Brr2 RNA helicase and links to retinal disease in humans.. RNA Biol 11(4):298-312 PMID: 24643059
- 7. Han H et al.. 2017. Multilayered Control of Alternative Splicing Regulatory Networks by Transcription Factors.. Mol Cell 65(3):539-553.e7 PMID: 28157508
- 8. Iturrate A et al.. 2022. Mutations in SCNM1 cause orofaciodigital syndrome due to minor intron splicing defects affecting primary cilia.. Am J Hum Genet 109(10):1828-1849 PMID: 36084634
