GO:0000375 RNA splicing, via transesterification reactions: Spliceosome Catalysis, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0000375 describes RNA splicing carried out by two sequential transesterification reactions, the chemical core of intron removal from precursor mRNA.
• The reaction is catalyzed by the spliceosome, a dynamic ribonucleoprotein machine whose RNA and protein components position the substrate and metal ions for catalysis.
• DExD/H-box RNA helicases use ATP to drive spliceosome assembly, rearrangement, and proofreading, ensuring fidelity of the transesterification steps.
• Cryo-electron microscopy structures have revealed that the spliceosome active site is built from RNA and that its mechanism is evolutionarily related to group II intron self-splicing.
• Monovalent metal ions and the RNA backbone promote the first transesterification reaction, highlighting the metal-dependent chemistry of splicing.
• Dysregulation of transesterification-based splicing contributes to cancer, including adult T-cell leukemia, making spliceosome components and regulators attractive research and therapeutic targets.
Description
RNA splicing, via transesterification reactions (GO:0000375) is the biological process in which introns are removed from precursor RNA and exons are joined through two consecutive transesterification reactions. This mechanism is fundamental to the maturation of most eukaryotic messenger RNAs and is carried out by the spliceosome, a large and highly dynamic ribonucleoprotein complex. Because the chemistry of splicing depends on precise positioning of RNA substrates and catalytic metal ions, the process is tightly regulated and coupled to transcription and other RNA-processing events. Researchers study GO:0000375 to understand how genetic information is faithfully converted into functional transcripts and how errors in this process contribute to disease. The term is also central to comparative and evolutionary biology, since the spliceosomal transesterification mechanism shares deep structural and mechanistic features with group II intron self-splicing. In this article, we summarize the definition, molecular players, regulatory features, disease links, and experimental approaches relevant to GO:0000375, with emphasis on how CRISPR-based models can be used to dissect its components.
RNA splicing, via transesterification reactions At A Glance
| GO ID | GO:0000375 |
|---|---|
| GO term | RNA splicing, via transesterification reactions |
| Ontology | biological_process |
| Definition | Splicing of RNA via a series of two transesterification reactions. |
| Synonym | pre-mRNA splicing factor activity; RNA splicing factor activity; transesterification mechanism; spliceosomal catalysis |
| Major function | Removal of introns and joining of exons in precursor RNA through two sequential transesterification reactions. |
| Catalytic machinery | The spliceosome, a ribonucleoprotein complex containing small nuclear RNAs and many protein factors. |
| Energy requirement | ATP-dependent RNA helicases drive assembly and rearrangements, while the transesterification chemistry itself is phosphodiester exchange. |
| Evolutionary link | Mechanistically and structurally related to group II intron self-splicing. |
What Is GO:0000375?
GO:0000375, RNA splicing, via transesterification reactions, is defined as splicing of RNA via a series of two transesterification reactions. In this process, a nucleophilic attack by a hydroxyl group on a phosphodiester bond breaks the RNA backbone and simultaneously forms a new phosphodiester bond, without the need for external energy in the chemical step itself. The first transesterification generates a lariat intermediate and frees the 5' exon, while the second transesterification joins the exons and releases the intron lariat. This definition distinguishes the term from other RNA-processing events that do not proceed through transesterification chemistry.
Why Is RNA splicing, via transesterification reactions Important in Cell Biology?
GO:0000375 is important because it defines the chemical heart of pre-mRNA splicing, a process that expands the coding capacity of eukaryotic genomes and is required for the expression of most protein-coding genes. Defects in spliceosomal transesterification or its regulation can alter transcript isoforms, introduce premature stop codons, or destabilize mRNAs, with consequences for cell growth, differentiation, and disease. Because the reaction is catalyzed by a dynamic ribonucleoprotein machine, it also serves as a paradigm for understanding RNA-catalyzed chemistry and metal-ion-dependent catalysis.
• It enables removal of introns and joining of exons, a prerequisite for mature mRNA production in eukaryotes.
• It is the defining catalytic activity of the spliceosome, a central target of mechanistic and structural studies.
• It is evolutionarily related to group II intron self-splicing, informing models of RNA evolution.
• Its fidelity depends on DExD/H-box helicases that use ATP to remodel RNA-protein interactions.
• Its dysregulation is implicated in cancer, including adult T-cell leukemia.
• It provides a framework for understanding metal-ion-assisted RNA catalysis.
• It is a focus of cryo-EM structural biology, revealing active-site architecture and conformational transitions.
• It is relevant to chloroplast and other organellar splicing systems that use related transesterification chemistry.
• It is a target for experimental perturbation using CRISPR-based gene editing of spliceosome components.
• It informs the design of RNA-based and small-molecule modulators of splicing for research and therapeutic purposes.
What Happens During RNA splicing, via transesterification reactions?
Recognition of splice sites and early spliceosome assembly
In simple terms: The cell first marks where the intron begins and ends so the splicing machine can bind.
Splicing begins with recognition of the 5' splice site, branch point, and 3' splice site by small nuclear ribonucleoproteins and associated factors, leading to formation of the early spliceosome. This step is ATP-dependent and involves DExD/H-box helicases that help rearrange RNA-RNA and RNA-protein interactions. The assembly process ensures that the correct splice sites are paired before catalysis, which is essential for the fidelity of the subsequent transesterification reactions.
First transesterification: lariat formation and 5' exon release
In simple terms: The first chemical cut forms a loop in the intron and frees the front exon.
In the first transesterification, the 2' hydroxyl of the branch-point adenosine attacks the phosphodiester bond at the 5' splice site, generating a lariat intron intermediate and a free 5' exon. Monovalent metal ion binding has been shown to promote this first transesterification reaction in the spliceosome, underscoring the metal-dependent nature of the catalysis. The reaction is reversible in principle but is driven forward by spliceosome rearrangements and the subsequent step.
Second transesterification: exon ligation and intron release
In simple terms: The second cut joins the two exons together and releases the intron loop.
In the second transesterification, the 3' hydroxyl of the 5' exon attacks the phosphodiester bond at the 3' splice site, ligating the exons and releasing the intron lariat. This step completes the chemical definition of GO:0000375 and is followed by disassembly of the spliceosome and turnover of the intron lariat. Structural studies have revealed how the active site is remodeled between the two transesterification steps to position the substrates for catalysis.
Spliceosome rearrangements and proofreading
In simple terms: The machine changes shape between cuts and checks that the right pieces are joined.
Between and after the transesterification reactions, the spliceosome undergoes extensive conformational rearrangements driven by DExD/H-box ATPases, which also provide proofreading to discard incorrect splice-site pairings. These rearrangements are essential for aligning the reactive groups and for coupling splicing to upstream and downstream events. Cryo-electron microscopy has captured multiple states of the spliceosome, illuminating how these transitions are coordinated.
Evolutionary and comparative context
In simple terms: The spliceosome works like an ancient self-splicing RNA that has gained protein helpers.
The transesterification mechanism of GO:0000375 is evolutionarily related to group II intron self-splicing, and structural comparisons have revealed shared catalytic cores. Related transesterification-based splicing also occurs in chloroplasts, where components of a putative chloroplast spliceosome have been identified. This evolutionary perspective helps researchers interpret spliceosome architecture and the roles of individual components.
Key Genes Involved in GO:0000375 RNA splicing, via transesterification reactions
The genes and proteins below are representative components and regulators of RNA splicing via transesterification reactions, based on the cited literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SNRPB | Core snRNP protein of the spliceosome | Structural and assembly studies of the transesterification machinery |
| SNRPD1 | Core snRNP protein of the spliceosome | Functional dissection of spliceosome assembly |
| SNRPE | Core snRNP protein of the spliceosome | Mechanistic studies of splice site recognition |
| SNRPF | Core snRNP protein of the spliceosome | Analysis of spliceosome dynamics |
| SNRPG | Core snRNP protein of the spliceosome | Investigation of snRNP composition |
| DDX39B | DExD/H-box RNA helicase | ATP-dependent remodeling during splicing |
| DDX5 | DExD/H-box RNA helicase | Regulation of spliceosome rearrangements |
| DDX17 | DExD/H-box RNA helicase | Co-transcriptional splicing regulation |
| DHX9 | DExD/H-box RNA helicase | RNA structure remodeling in splicing |
| DHX15 | DExD/H-box RNA helicase | Catalytic step regulation |
| PRPF8 | Core spliceosome protein | Active-site architecture and catalysis |
| SNRNP200 | RNA helicase in the spliceosome | Proofreading and rearrangement |
| EFTUD2 | GTPase-associated spliceosome factor | Spliceosome activation and catalysis |
| SART1 | Spliceosome component | Assembly and stability studies |
| RBM22 | Spliceosome-associated RNA-binding protein | Catalytic step and exon ligation |
| CWC22 | Spliceosome assembly factor | Exon junction complex coupling |
| Tpt1 | RNA terminal phosphomonoesterase in some systems | Related RNA processing and splicing factor studies |
How Is RNA splicing, via transesterification reactions Regulated?
Regulation of RNA splicing via transesterification reactions occurs at multiple levels, including ATP-dependent remodeling by DExD/H-box helicases, post-translational modification of spliceosome components, and coupling to transcription. These regulatory inputs ensure that the two transesterification steps occur in the correct order and only on appropriate substrates. In cancer, alternative splicing programs can be rewired, as illustrated in adult T-cell leukemia, where splicing changes contribute to disease biology. Metal ion availability and local RNA structure also influence the catalytic steps, as shown for monovalent metal ion promotion of the first transesterification.
RNA splicing, via transesterification reactions and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DDX39B | Splicing dysregulation in cancer | Knockout and point-mutation cell lines |
| PRPF8 | Spliceosome-related retinal and hematologic phenotypes | Knock-in of patient variants |
| SNRPB | Spliceosome dysfunction in developmental disorders | Knockout and rescue models |
| DHX15 | Altered catalytic step in malignancy | Overexpression and knockout models |
| RBM22 | Splicing-related disease mechanisms | Point-mutation knock-in |
Cancer and splicing dysregulation
Altered RNA splicing, including changes in transesterification-based intron removal, is increasingly recognized in cancer. In adult T-cell leukemia, alternative RNA splicing contributes to the molecular pathology of the disease, highlighting how splicing regulation can be subverted in malignancy. Because the transesterification reactions are central to splicing, mutations or expression changes in spliceosome components can shift isoform ratios and affect tumor cell behavior.
Spliceosome mutations and hematologic disorders
Mutations in spliceosome components are associated with hematologic disorders, and mechanistic studies of the transesterification machinery help explain how these mutations alter splicing fidelity. Structural and biochemical work on the spliceosome provides a framework for interpreting the functional impact of such mutations.
Neurodevelopmental and degenerative contexts
Proper regulation of transesterification-based splicing is required for normal neuronal gene expression, and disruption of splicing factors has been linked to neurodevelopmental and degenerative phenotypes in model systems. Research using yeast and mammalian models continues to clarify how spliceosome dysfunction contributes to these conditions.
From RNA splicing, via transesterification reactions-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is a spliceosome component essential for transesterification? | CRISPR knockout cell line |
| Does a patient variant alter the first transesterification? | Point-mutation knock-in |
| Can a tagged protein report spliceosome dynamics? | Tagged knock-in |
| Does overexpression of a helicase change splicing patterns? | Overexpression cell model |
| Which cofactors are required for exon ligation? | Knockout and rescue |
| How does a metal-ion-site mutation affect catalysis? | Point-mutation knock-in |
How to Study the RNA splicing, via transesterification reactions Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Splice isoform usage and intron retention | Global splicing changes after perturbation |
| In vitro splicing assay | Transesterification activity | Mechanistic studies of catalysis |
| Cryo-EM | Spliceosome structure and states | Active-site architecture |
| CRISPR knockout | Gene essentiality for splicing | Functional dissection of components |
| Point-mutation knock-in | Effect of specific residues on catalysis | Active-site and metal-ion studies |
| Overexpression | Gain-of-function splicing effects | Helicase and regulator studies |
| Proteomics | Spliceosome composition and interactions | Assembly and dynamics |
| Imaging | Localization of splicing factors | Co-transcriptional splicing |
RNA sequencing and splice isoform analysis
RNA-seq is widely used to measure changes in splicing patterns, including intron retention and exon skipping, following perturbation of spliceosome components. These approaches help link specific genes to the transesterification steps of GO:0000375.
Biochemical reconstitution and catalysis assays
In vitro splicing assays with nuclear extracts or purified components allow direct measurement of the two transesterification reactions and the effects of mutations or metal ions. Such assays are essential for mechanistic conclusions about GO:0000375.
Structural biology and cryo-electron microscopy
Cryo-EM structures of the spliceosome at different stages have revealed the architecture of the active site and the conformational changes that accompany transesterification. These structures guide functional experiments and evolutionary comparisons.
Genetic and CRISPR perturbation
CRISPR-based knockout, knock-in, and point-mutation models enable causal testing of spliceosome components in cells and organisms. Combined with RNA-seq and biochemical assays, these models connect genotype to splicing outcomes.
How CRISPR Can Be Used to Study GO:0000375 RNA splicing, via transesterification reactions
Knockout
CRISPR knockout of spliceosome components can reveal which factors are essential for the transesterification reactions and for cell viability. Such models are useful for dissecting the contribution of individual helicases and snRNP proteins to splicing fidelity.
Point Mutation
Point-mutation knock-in allows precise testing of catalytic residues and metal-ion-coordinating positions implicated in the first and second transesterification reactions. These models help distinguish catalytic defects from assembly defects.
Knock-in
Tagged knock-in of spliceosome proteins enables visualization and affinity purification of complexes during splicing. Knock-in of disease-associated variants can model splicing-related pathology in relevant cell types.
Overexpression
Overexpression of splicing regulators or helicases can drive changes in isoform ratios and reveal gain-of-function effects on transesterification-based splicing. These models complement loss-of-function studies.
How EDITGENE Supports RNA splicing, via transesterification reactions Research
Researchers studying RNA splicing, via transesterification reactions-related genes often need to determine whether a candidate gene is causally involved in spliceosome assembly, catalysis, or regulation. EDITGENE provides CRISPR-based cell models and screening services to test these hypotheses with publication-ready rigor.
Contact EDITGENE today to design your custom CRISPR model for RNA splicing, via transesterification reactions research.
Frequently Asked Questions About RNA splicing, via transesterification reactions
What is RNA splicing, via transesterification reactions?
It is the biological process GO:0000375 in which introns are removed and exons joined through two sequential transesterification reactions catalyzed by the spliceosome.
What genes are involved in RNA splicing, via transesterification reactions?
Genes encoding snRNP proteins, DExD/H-box helicases, and core spliceosome factors such as SNRPB, DDX39B, PRPF8, and DHX15 are involved.
What is the GO ID for RNA splicing, via transesterification reactions?
The GO ID is GO:0000375.
How many transesterification reactions occur during splicing?
Two: the first forms the lariat and releases the 5' exon, and the second ligates the exons and releases the intron.
What is the role of the spliceosome in this process?
The spliceosome positions the RNA substrates and metal ions to catalyze the two transesterification reactions.
Are metal ions required for transesterification?
Yes, monovalent metal ion binding has been shown to promote the first transesterification reaction.
How is splicing related to disease?
Dysregulated splicing, including in adult T-cell leukemia, can alter gene expression and contribute to disease.
What methods are used to study transesterification-based splicing?
RNA-seq, in vitro splicing assays, cryo-EM, and CRISPR perturbation are commonly used.
Is transesterification splicing evolutionarily conserved?
Yes, it is related to group II intron self-splicing and occurs in diverse systems including chloroplasts.
Can CRISPR be used to study spliceosome components?
Yes, CRISPR knockout, point-mutation, knock-in, and overexpression models are used to dissect spliceosome function.
Conclusion
GO:0000375, RNA splicing via transesterification reactions, captures the two-step chemical mechanism that removes introns and joins exons in precursor RNA. The process is executed by the spliceosome, a dynamic ribonucleoprotein machine whose assembly, catalysis, and proofreading are driven by RNA helicases and metal ions. Because of its central role in gene expression and its links to cancer and other diseases, this term remains a major focus of mechanistic, structural, and translational research. CRISPR-based models and modern RNA analysis methods provide powerful tools to dissect the components and regulation of this essential process.
References
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- 2. Senn KA et al.. 2024. Mechanisms and regulation of spliceosome-mediated pre-mRNA splicing in Saccharomyces cerevisiae.. Wiley Interdiscip Rev RNA 15(4):e1866 PMID: 38972853
- 3. Liu YC et al.. 2015. Functional roles of DExD/H-box RNA helicases in Pre-mRNA splicing.. J Biomed Sci 22(1):54 PMID: 26173448
- 4. Jacobs J et al.. 2010. RNA trans-splicing: identification of components of a putative chloroplast spliceosome.. Eur J Cell Biol 89(12):932-9 PMID: 20705358
- 5. Galej WP. 2018. Structural studies of the spliceosome: past, present and future perspectives.. Biochem Soc Trans 46(6):1407-1422 PMID: 30420411
- 6. Galej WP et al.. 2018. Molecular Mechanism and Evolution of Nuclear Pre-mRNA and Group II Intron Splicing: Insights from Cryo-Electron Microscopy Structures.. Chem Rev 118(8):4156-4176 PMID: 29377672
- 7. Munir A et al.. 2019. NAD(+)-dependent RNA terminal 2' and 3' phosphomonoesterase activity of a subset of Tpt1 enzymes.. RNA 25(7):783-792 PMID: 31019096
- 8. Aupič J et al.. 2023. Monovalent metal ion binding promotes the first transesterification reaction in the spliceosome.. Nat Commun 14(1):8482 PMID: 38123540
