GO:0016604 nuclear body: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0016604 nuclear body is a membraneless organelle in the nucleoplasm, usually visible by confocal microscopy, that concentrates specific proteins and RNAs to carry out nuclear functions.
• Nuclear bodies are dynamic, phase-separated condensates whose assembly and composition depend on protein concentration and multivalent interactions.
• Major nuclear body subtypes include nuclear speckles, Cajal bodies, and PML nuclear bodies, each with distinct protein and RNA components.
• Nuclear speckles are positioned near highly active genes and influence mRNA splicing efficiency by organizing chromatin around them.
• Cajal bodies serve as meeting places for spliceosomal snRNPs and are marked by coilin.
• Disruption of nuclear body components is linked to cancer, developmental disorders, and oocyte biology, making these structures important research and therapeutic targets.
Description
The nuclear body (GO:0016604) is a membraneless organelle present in the nucleoplasm and usually visible by confocal microscopy. Unlike membrane-bound organelles, nuclear bodies form through the self-assembly of specific proteins and RNAs into phase-separated condensates that concentrate molecular machinery for specialized nuclear functions. These structures include nuclear speckles, Cajal bodies, PML nuclear bodies, and others, each defined by distinct marker proteins and roles in gene expression, RNA processing, and genome organization. Researchers study nuclear bodies to understand how the nucleus organizes its activities in space and time, and how disruption of these structures contributes to human disease. Because nuclear bodies are dynamic and composition-dependent, they are sensitive to changes in protein concentration, post-translational modifications, and cellular forces, making them key models for phase separation and nuclear architecture.
nuclear body At A Glance
| GO ID | GO:0016604 |
|---|---|
| GO term | nuclear body |
| Ontology | cellular_component |
| Synonym | none |
| Major function | Membraneless organelle in the nucleoplasm that concentrates proteins and RNAs for specialized nuclear processes such as splicing, snRNP maturation, and stress response |
| Subtypes | Nuclear speckles, Cajal bodies, PML nuclear bodies, and other condensates |
| Assembly mechanism | Phase separation driven by multivalent protein-protein and protein-RNA interactions |
| Visibility | Usually visible by confocal microscopy |
| Key marker proteins | SRRM2 (nuclear speckles), coilin (Cajal bodies), PML (PML nuclear bodies) |
What Is GO:0016604?
According to the Gene Ontology, GO:0016604 nuclear body is a membraneless organelle present in the nucleoplasm and usually visible by confocal microscopy. This definition emphasizes that nuclear bodies lack a lipid bilayer, reside within the nucleoplasm, and are large enough to be resolved by standard fluorescence confocal imaging. They are dynamic compartments that concentrate specific proteins and RNAs, and their assembly often depends on multivalent interactions and phase separation.
Why Is nuclear body Important in Cell Biology?
Nuclear bodies are important because they organize the nucleoplasm into functional compartments that enhance the efficiency and specificity of gene expression and RNA processing. They influence how chromatin is arranged around active genes, how spliceosomal components are stored and assembled, and how cells respond to stress. Because they are membraneless and dynamic, nuclear bodies also serve as paradigms for understanding phase separation in living cells. Their dysfunction has been linked to cancer, oocyte biology, and developmental processes, making them relevant to both basic research and disease modeling.
• Nuclear bodies concentrate splicing factors and influence mRNA splicing efficiency by organizing chromatin around nuclear speckles.
• Cajal bodies are meeting places for spliceosomal snRNPs and are essential for snRNP maturation and assembly.
• PML nuclear bodies can assemble in specialized contexts such as mouse oocytes, highlighting their role in development.
• Phase separation of proteins like SRRM2 drives the assembly of nuclear speckle subcompartments.
• Composition-dependent thermodynamics govern the formation and stability of intracellular phase-separated compartments including nuclear bodies.
• Cytoplasmic forces can functionally reorganize nuclear condensates in oocytes, linking mechanical cues to nuclear organization.
• Proximal proteomics has revealed a landscape of human nuclear condensates, providing a resource for studying nuclear body composition.
• Disruption of nuclear body components is associated with cancer and other diseases, making them potential therapeutic targets.
• Nuclear bodies are visible by confocal microscopy, enabling live-cell imaging and dynamic studies.
• Understanding nuclear body assembly can inform synthetic biology and the design of membraneless organelles.
Core Biology of GO:0016604 nuclear body
What Happens During nuclear body Assembly?
In simple terms: Nuclear bodies form when certain proteins and RNAs come together in the nucleus without a membrane, like oil droplets in water.
Nuclear bodies assemble through a process of phase separation, where multivalent interactions among proteins and RNAs drive the formation of distinct condensates. This assembly is composition-dependent and can be influenced by protein concentration, post-translational modifications, and cellular forces. For example, SRRM2 phase separation drives the assembly of nuclear speckle subcompartments. In oocytes, cytoplasmic forces can functionally reorganize nuclear condensates, showing that assembly is dynamic and responsive to cellular context.
What Happens During nuclear body Function?
In simple terms: Once formed, nuclear bodies act as hubs that concentrate molecules to speed up and organize nuclear tasks like RNA splicing.
Nuclear bodies function as organizational hubs that concentrate specific factors to enhance the efficiency of nuclear processes. Nuclear speckles are positioned near highly active genes and drive mRNA splicing efficiency by organizing chromatin around them. Cajal bodies serve as meeting places for spliceosomal snRNPs, facilitating their assembly and maturation. PML nuclear bodies can assemble in specialized contexts such as mouse oocytes, where they may participate in developmental regulation. Proximal proteomics has revealed a landscape of human nuclear condensates, highlighting the diverse functional roles of these structures.
Structure and Composition of nuclear body
In simple terms: Nuclear bodies are made of specific proteins and RNAs that stick together to form distinct compartments without a membrane.
The structure of nuclear bodies is defined by their protein and RNA components. Nuclear speckles are marked by SRRM2 and other splicing factors. Cajal bodies are marked by coilin and contain spliceosomal snRNPs. PML nuclear bodies are defined by the PML protein. These components are held together by multivalent interactions, and their composition can vary depending on cell type and physiological state. The membraneless nature of nuclear bodies allows them to be dynamic and rapidly exchange components with the surrounding nucleoplasm.
Molecular Mechanism of nuclear body
In simple terms: The molecular mechanism of nuclear bodies involves weak, multivalent interactions that allow them to form, dissolve, and exchange components quickly.
At the molecular level, nuclear bodies are driven by phase separation, which depends on the concentration and valency of interacting proteins and RNAs. SRRM2 phase separation is a key driver of nuclear speckle subcompartment assembly. The thermodynamics of intracellular phase separation are composition-dependent, meaning that small changes in protein concentration or modification can shift the balance between assembled and dispersed states. Cytoplasmic forces can also functionally reorganize nuclear condensates, indicating that mechanical cues can regulate their molecular organization. Proximal proteomics has provided a comprehensive view of the protein landscape within human nuclear condensates, revealing the molecular players involved.
Key Genes Involved in GO:0016604 nuclear body
The following genes and proteins are key components or regulators of nuclear bodies, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SRRM2 | Phase separation driver of nuclear speckle subcompartments | Studying nuclear speckle assembly and splicing regulation |
| PML | Marker protein of PML nuclear bodies | Investigating PML nuclear body assembly in oocytes and disease |
| Coilin | Marker protein of Cajal bodies | Understanding Cajal body function in snRNP maturation |
| SMN1 | Survival motor neuron protein involved in snRNP assembly | Cajal body-related snRNP biogenesis and spinal muscular atrophy |
| SF3B1 | Splicing factor component of nuclear speckles | Splicing efficiency and cancer mutations |
| SRSF1 | Serine/arginine-rich splicing factor in nuclear speckles | Regulation of mRNA splicing and nuclear speckle dynamics |
| SRSF2 | Splicing factor enriched in nuclear speckles | Splicing regulation and myeloid malignancies |
| U2AF1 | Splicing factor associated with nuclear speckles | Splicing efficiency and cancer |
| SON | Nuclear speckle protein involved in splicing | Nuclear speckle organization and function |
| SC35 (SRSF2) | Classic marker of nuclear speckles | Nuclear speckle visualization and dynamics |
| Fibrillarin | Component of Cajal bodies and nucleoli | Cajal body function and rRNA processing |
| Nopp140 | Cajal body protein | Cajal body assembly and snRNP trafficking |
| SMN complex | Assembles snRNPs in Cajal bodies | snRNP maturation and disease |
| Ddx39b | RNA helicase in nuclear speckles | mRNA export and splicing |
| Rbm39 | Splicing factor in nuclear speckles | Splicing regulation and cancer |
| CPSF6 | Nuclear speckle-associated factor | 3' end processing and nuclear body function |
| NONO | Nuclear body protein involved in RNA processing | Paraspeckle and nuclear body research |
How Is nuclear body Regulated?
Nuclear body assembly and function are regulated by multiple mechanisms. The composition-dependent thermodynamics of phase separation means that changes in protein concentration, post-translational modifications, and RNA levels can shift the equilibrium between assembled and dispersed states. SRRM2 phase separation is a key regulatory step in nuclear speckle subcompartment assembly. Cytoplasmic forces can functionally reorganize nuclear condensates in oocytes, indicating that mechanical cues can regulate nuclear body organization. Additionally, the landscape of human nuclear condensates is shaped by the availability of specific proteins and RNAs, as revealed by proximal proteomics.
nuclear body and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PML | Acute promyelocytic leukemia | Knockout or knock-in of PML-RARA fusion in cell lines |
| SMN1 | Spinal muscular atrophy | Knockout or point mutation in motor neuron models |
| SF3B1 | Myelodysplastic syndromes and cancer | Point mutation knock-in in hematopoietic cells |
| SRSF2 | Myeloid malignancies | Knock-in of mutant SRSF2 in cell lines |
| U2AF1 | Cancer | Knockout or point mutation in cancer cell lines |
Nuclear Bodies in Cancer
Alterations in nuclear body components, particularly splicing factors enriched in nuclear speckles, are associated with cancer. Mutations in splicing factors such as SF3B1, SRSF2, and U2AF1 are found in various malignancies and can affect splicing efficiency, which is linked to nuclear speckle function. PML nuclear bodies are disrupted in acute promyelocytic leukemia, where the PML-RARA fusion protein impairs their assembly. Understanding how nuclear bodies contribute to cancer can inform targeted therapies.
Nuclear Bodies in Neurodegeneration and Developmental Disorders
Cajal bodies are involved in the maturation of spliceosomal snRNPs, and defects in this process are linked to spinal muscular atrophy, a neurodegenerative disease caused by mutations in SMN1. Disruption of Cajal body function can lead to impaired snRNP assembly and RNA processing, contributing to disease pathology. Additionally, nuclear body-like structures can assemble in mouse oocytes, suggesting roles in reproductive biology and development.
Nuclear Bodies in Oocyte Biology
PML nuclear body-like structures can assemble in mouse oocytes, and cytoplasmic forces can functionally reorganize nuclear condensates in oocytes. These findings link nuclear body dynamics to developmental processes and mechanical regulation in reproductive cells. Studying nuclear bodies in oocytes can provide insights into fertility and early development.
From nuclear body-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the role of SRRM2 in nuclear speckle assembly? | Knockout or overexpression of SRRM2 in cell lines |
| How does PML nuclear body assembly occur in oocytes? | Knock-in of tagged PML in mouse oocytes |
| What is the function of coilin in Cajal bodies? | Knockout of coilin in cell lines |
| How do splicing factor mutations affect nuclear speckles? | Point mutation knock-in of SF3B1 or SRSF2 |
| How do cytoplasmic forces affect nuclear condensates? | Live-cell imaging in oocytes with mechanical manipulation |
| What is the composition of human nuclear condensates? | Proximal proteomics in knockout or tagged cell lines |
How to Study the nuclear body Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Confocal microscopy | Visualization of nuclear bodies | Identifying and tracking nuclear bodies in cells |
| Live-cell imaging | Dynamic assembly and disassembly | Studying nuclear body dynamics over time |
| Proximal proteomics | Protein composition of nuclear condensates | Mapping the landscape of nuclear bodies |
| In vitro phase separation | Condensate formation and thermodynamics | Testing phase separation of SRRM2 and other proteins |
| RNA-seq | mRNA splicing efficiency | Linking nuclear speckles to splicing outcomes |
| Chromatin conformation capture | Genome organization around nuclear bodies | Assessing spatial organization of active genes |
| Fluorescence recovery after photobleaching (FRAP) | Molecular exchange rates | Measuring dynamics of nuclear body components |
| Immunofluorescence | Localization of marker proteins | Identifying nuclear body subtypes |
Confocal Microscopy and Live-Cell Imaging
Confocal microscopy is the standard method to visualize nuclear bodies, as they are usually visible by this technique. Live-cell imaging with fluorescently tagged marker proteins such as SRRM2, coilin, or PML allows researchers to track nuclear body dynamics, assembly, and disassembly in real time.
Proximal Proteomics
Proximal proteomics, such as proximity labeling, has been used to reveal the landscape of human nuclear condensates. This method identifies proteins that reside in or near nuclear bodies, providing a comprehensive view of their composition and helping to define subtype-specific components.
Phase Separation Assays
In vitro phase separation assays with purified proteins like SRRM2 can reconstitute nuclear body assembly and test the effects of concentration, mutations, and RNA on condensate formation. These assays help determine the thermodynamic principles governing nuclear body assembly.
Genome Organization and Splicing Analysis
Techniques such as RNA-seq and chromatin conformation capture can assess how nuclear speckles influence mRNA splicing efficiency and genome organization around active genes. These methods link nuclear body function to gene expression outcomes.
How CRISPR Can Be Used to Study GO:0016604 nuclear body
Knockout
CRISPR knockout of nuclear body component genes, such as SRRM2, coilin, or PML, can disrupt nuclear body formation and function, allowing researchers to study their roles in splicing, snRNP maturation, and stress responses. Knockout cell models are essential for determining causality.
Point Mutation
Point mutation knock-in using CRISPR can mimic disease-associated mutations in splicing factors like SF3B1 or SRSF2, which are enriched in nuclear speckles. These models help dissect how specific mutations affect nuclear body composition and splicing efficiency.
Knock-in
Knock-in of fluorescent or epitope tags into endogenous nuclear body genes, such as PML or coilin, enables live-cell imaging and proteomic analysis of nuclear bodies in their native context. Tagged knock-in models are valuable for tracking nuclear body dynamics.
Overexpression
Overexpression of nuclear body proteins like SRRM2 can drive the formation of enlarged or aberrant condensates, helping to test the sufficiency of phase separation for nuclear body assembly. Overexpression models are useful for studying the concentration dependence of phase separation.
How EDITGENE Supports nuclear body Research
Researchers studying nuclear body-related genes often need to determine whether a candidate gene is causally involved in nuclear body assembly, function, or disease. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for nuclear body research.
Frequently Asked Questions About nuclear body
What is a nuclear body (GO:0016604)?
A nuclear body is a membraneless organelle present in the nucleoplasm and usually visible by confocal microscopy, as defined by the Gene Ontology.
What genes are involved in nuclear bodies?
Key genes include SRRM2, PML, coilin, SMN1, SF3B1, SRSF2, and U2AF1, among others.
What is the function of nuclear speckles?
Nuclear speckles are nuclear bodies that drive mRNA splicing efficiency by organizing chromatin around active genes.
What are Cajal bodies?
Cajal bodies are nuclear bodies that serve as meeting places for spliceosomal snRNPs and are marked by coilin.
How are nuclear bodies assembled?
Nuclear bodies assemble through phase separation driven by multivalent protein-protein and protein-RNA interactions.
Are nuclear bodies visible by confocal microscopy?
Yes, nuclear bodies are usually visible by confocal microscopy according to the GO definition.
What diseases are linked to nuclear bodies?
Nuclear body dysfunction is linked to cancer, spinal muscular atrophy, and oocyte developmental processes.
How can I study nuclear bodies in the lab?
Common methods include confocal microscopy, live-cell imaging, proximal proteomics, and phase separation assays.
What is the role of SRRM2 in nuclear bodies?
SRRM2 phase separation drives the assembly of nuclear speckle subcompartments.
Can CRISPR be used to study nuclear bodies?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to study nuclear body genes and their functions.
Conclusion
Nuclear bodies (GO:0016604) are dynamic, membraneless organelles that organize key nuclear processes such as mRNA splicing and snRNP maturation. Their assembly via phase separation and their composition-dependent properties make them central to understanding nuclear architecture and disease. Continued research using advanced imaging, proteomics, and CRISPR models will further illuminate their roles and therapeutic potential.
References
- 1. Bhat P et al.. 2024. Genome organization around nuclear speckles drives mRNA splicing efficiency.. Nature 629(8014):1165-1173 PMID: 38720076
- 2. Zhang M et al.. 2024. SRRM2 phase separation drives assembly of nuclear speckle subcompartments.. Cell Rep 43(3):113827 PMID: 38381607
- 3. Riback JA et al.. 2020. Composition-dependent thermodynamics of intracellular phase separation.. Nature 581(7807):209-214 PMID: 32405004
- 4. Udagawa O et al.. 2022. Promyelocytic leukemia nuclear body-like structures can assemble in mouse oocytes.. Biol Open 11(6) PMID: 35579421
- 5. Li R et al.. 2025. Proximal proteomics reveals a landscape of human nuclear condensates.. Nat Cell Biol 27(12):2198-2213 PMID: 41315769
- 6. Stanek D et al.. 2006. The Cajal body: a meeting place for spliceosomal snRNPs in the nuclear maze.. Chromosoma 115(5):343-54 PMID: 16575476
- 7. Al Jord A et al.. 2022. Cytoplasmic forces functionally reorganize nuclear condensates in oocytes.. Nat Commun 13(1):5070 PMID: 36038550
- 8. Morris GE. 2008. The Cajal body.. Biochim Biophys Acta 1783(11):2108-15 PMID: 18755223
