GO:0097165 nuclear stress granule: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0097165 nuclear stress granule is a dense aggregation in the nucleus composed of proteins and RNAs that appears when the cell is under stress.
• Nuclear stress granules form in response to stress and are distinct from cytoplasmic stress granules, although they share some protein components.
• Key proteins involved in nuclear stress granule assembly include TIAR, G3BP1, and other RNA-binding proteins that undergo phase separation.
• Nuclear stress granules are implicated in various diseases, including cancer and neurodegenerative disorders, and are being studied as potential therapeutic targets.
• CRISPR-based approaches enable functional dissection of nuclear stress granule components through knockout, point mutation, knock-in, and overexpression models.
• Understanding nuclear stress granule biology requires integrating imaging, proteomics, and transcriptomics to reveal their dynamic composition and regulation.
Description
Nuclear stress granules (GO:0097165) are membraneless organelles that assemble in the nucleus under stress conditions, composed of proteins and RNAs. They are part of the cellular stress response and are distinct from cytoplasmic stress granules, though they share certain components and assembly principles. The formation of these granules is driven by liquid-liquid phase separation of RNA-binding proteins with low-complexity domains, a process that can also lead to pathological fibrillization. Nuclear stress granules are increasingly recognized for their roles in gene regulation, RNA processing, and disease pathogenesis. Researchers study nuclear stress granules to understand how cells cope with stress and how dysregulation contributes to diseases such as cancer and neurodegeneration. The dynamic nature of these granules requires advanced tools to track their assembly, composition, and function in real time.
nuclear stress granule At A Glance
| GO ID | GO:0097165 |
|---|---|
| GO term | nuclear stress granule |
| Ontology | cellular_component |
| Synonym | None |
| Definition | A dense aggregation in the nucleus composed of proteins and RNAs that appear when the cell is under stress. |
| Major function | Stress response, RNA processing, gene regulation |
| Related cellular component | Cytoplasmic stress granule, nuclear speckle, PML body |
| Assembly mechanism | Liquid-liquid phase separation of RNA-binding proteins |
| Key proteins | TIAR, G3BP1, HMGB1, NCOA7, TRIM21 |
What Is GO:0097165?
The Gene Ontology term GO:0097165 describes a nuclear stress granule as a dense aggregation in the nucleus composed of proteins and RNAs that appear when the cell is under stress. This definition captures the essential features: nuclear localization, stress-induced formation, and composition of both proteins and RNAs. Unlike cytoplasmic stress granules, nuclear stress granules are found within the nucleus and may have distinct assembly pathways and functions. They are considered membraneless organelles, relying on phase separation rather than lipid bilayers to compartmentalize their components.
Why Is nuclear stress granule Important in Cell Biology?
Nuclear stress granules are critical for cellular adaptation to stress, influencing RNA metabolism, gene expression, and cell survival. Their dysregulation has been linked to cancer, neurodegenerative diseases, and aging, making them attractive targets for therapeutic intervention. Understanding their assembly and function can provide insights into fundamental cell biology and disease mechanisms.
• Nuclear stress granules modulate RNA processing and stability during stress, affecting gene expression programs.
• They are implicated in cancer progression, where stress adaptation supports tumor cell survival.
• Dysregulation of nuclear stress granules contributes to neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS).
• They play a role in aging, as shown by studies linking stress granule clearance to ovarian aging.
• Nuclear stress granules are involved in immune responses, including interleukin-33 secretion.
• They serve as models for studying liquid-liquid phase separation and membraneless organelle biology.
• Components of nuclear stress granules, such as G3BP1, are regulated by ubiquitination and autophagy.
• Nuclear stress granule formation can disrupt nucleocytoplasmic transport, impacting cellular homeostasis.
• They are potential biomarkers and therapeutic targets in stress-related diseases.
• Studying nuclear stress granules requires advanced imaging and CRISPR-based functional genomics.
What Happens During nuclear stress granule?
Stress Sensing and Initiation
In simple terms: When a cell experiences stress, it triggers a response that leads to the formation of nuclear stress granules.
Nuclear stress granule assembly is initiated by cellular stress, such as heat shock, oxidative stress, or hypoxia. This stress activates signaling pathways that modify RNA-binding proteins, promoting their condensation into granules. For example, hypoxia induces lactylation of HMGB1 at K177, which drives nuclear export of TIAR and promotes stress granule formation. The initiation phase involves changes in protein modifications and RNA interactions that seed granule formation.
Phase Separation and Assembly
In simple terms: Proteins and RNAs come together through a process called phase separation to form dense droplets in the nucleus.
Phase separation is a key mechanism driving nuclear stress granule assembly. Low-complexity domains in RNA-binding proteins, such as those in TIAR and G3BP1, promote liquid-liquid phase separation, forming membraneless organelles. This process is dynamic and reversible, allowing granules to assemble and disassemble in response to stress. The composition of these granules includes various proteins and RNAs that are recruited during assembly.
Maturation and Dynamics
In simple terms: Once formed, nuclear stress granules can grow, change composition, and interact with other nuclear structures.
After initial assembly, nuclear stress granules mature by recruiting additional components and undergoing fusion or fission events. They can interact with nuclear structures such as chromatin and nuclear speckles, influencing gene expression. The dynamics of these granules are regulated by post-translational modifications and chaperone proteins. For instance, TRIM21-mediated ubiquitination of G3BP1 modulates stress granule homeostasis and clearance.
Disassembly and Clearance
In simple terms: When stress subsides, nuclear stress granules are disassembled and their components are either recycled or degraded.
Disassembly of nuclear stress granules occurs when stress is relieved, allowing cells to return to normal function. This process involves autophagy-dependent elimination and ubiquitination pathways. NCOA7, a V-ATPase-interacting protein, mediates stress granule clearance and mitigates ovarian aging. Defects in clearance can lead to persistent granules, which are associated with pathological conditions.
Key Genes Involved in GO:0097165 nuclear stress granule
The following genes and proteins are key components or regulators of nuclear stress granules, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| TIAR | RNA-binding protein, core component | Promotes stress granule assembly; regulated by HMGB1 lactylation |
| G3BP1 | RNA-binding protein, scaffold | Modulated by TRIM21-mediated ubiquitination and autophagy |
| HMGB1 | Chromatin protein, regulator | Lactylation at K177 drives TIAR export and stress granule formation |
| NCOA7 | V-ATPase-interacting protein | Mediates stress granule clearance; linked to ovarian aging |
| TRIM21 | E3 ubiquitin ligase | Ubiquitinates G3BP1 to regulate stress granule homeostasis |
| TDP-43 | RNA-binding protein | Implicated in ALS; forms pathological aggregates |
| FUS | RNA-binding protein | Involved in phase separation and neurodegeneration |
| hnRNPA1 | RNA-binding protein | Low-complexity domain drives phase separation |
| ATXN2 | RNA-binding protein | Modulates stress granule formation; linked to ALS |
| PABP | Poly(A)-binding protein | Component of stress granules; affects RNA stability |
| eIF4G | Translation initiation factor | Recruited to stress granules; impacts translation |
| RACK1 | Ribosome-associated protein | Involved in stress granule assembly |
| DDX3 | RNA helicase | Regulates stress granule dynamics |
| Caprin-1 | RNA-binding protein | Promotes stress granule formation |
| USP10 | Deubiquitinase | Regulates stress granule disassembly |
| VCP | AAA-ATPase | Involved in stress granule clearance |
| SQSTM1/p62 | Autophagy receptor | Mediates autophagic clearance of stress granules |
How Is nuclear stress granule Regulated?
Nuclear stress granule formation and disassembly are tightly regulated by post-translational modifications, signaling pathways, and quality control mechanisms. Ubiquitination of G3BP1 by TRIM21 modulates stress granule homeostasis and promotes autophagy-dependent elimination. Lactylation of HMGB1 at K177 drives nuclear export of TIAR, promoting stress granule formation under hypoxia. NCOA7, a V-ATPase-interacting protein, mediates stress granule clearance and mitigates ovarian aging. Additionally, stress granule assembly can disrupt nucleocytoplasmic transport, impacting cellular homeostasis. These regulatory mechanisms ensure that stress granules are transient and responsive to cellular needs.
nuclear stress granule and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| G3BP1 | Cancer, stress adaptation | Knockout in cancer cell lines to assess stress granule formation and drug sensitivity |
| TDP-43 | ALS, frontotemporal dementia | Point mutation knock-in in iPSCs to study aggregation and toxicity |
| FUS | ALS | Overexpression of mutant FUS in neuronal cells to analyze phase separation |
| NCOA7 | Ovarian aging | Knockout in ovarian cells to evaluate stress granule clearance |
| HMGB1 | Hypoxia-induced stress | Point mutation (K177) knock-in to study lactylation and TIAR export |
Nuclear Stress Granules in Cancer
Nuclear stress granules support cancer cell survival under stress conditions, such as hypoxia and chemotherapy. They modulate RNA processing and translation, enabling tumor cells to adapt to adverse environments. Components like G3BP1 and TIAR are overexpressed in various cancers and correlate with poor prognosis. Targeting stress granule assembly or clearance pathways represents a potential therapeutic strategy.
Neurodegenerative Diseases
Dysregulation of nuclear stress granules is implicated in neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. Pathological aggregation of RNA-binding proteins such as TDP-43 and FUS, which are components of stress granules, leads to neuronal toxicity. Mutations in genes like ATXN2 and hnRNPA1 affect stress granule dynamics and contribute to disease. Understanding these mechanisms may reveal new therapeutic targets.
Aging and Ovarian Function
Stress granule clearance declines with age, contributing to ovarian aging. NCOA7-mediated clearance of stress granules mitigates ovarian aging, highlighting the importance of granule homeostasis in reproductive aging. Defective clearance leads to persistent granules and cellular dysfunction.
Immune Responses
Nuclear stress granules are involved in immune responses, including the regulation of interleukin-33 secretion. Allergen protease-activated stress granule assembly and gasdermin D fragmentation control IL-33 secretion, linking stress granules to allergic inflammation.
From nuclear stress granule-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate nuclear stress granule assembly? | Knockout cell line (e.g., CRISPR-Cas9) followed by stress induction and imaging |
| Does a specific mutation in gene Y affect stress granule dynamics? | Point mutation knock-in cell line (e.g., K177 in HMGB1) |
| How does gene Z contribute to stress granule clearance? | Knockout or overexpression of gene Z in cells, with autophagy flux assays |
| What is the interactome of nuclear stress granule protein A? | Tagged knock-in (e.g., GFP or BioID) followed by proximity labeling and proteomics |
| Can overexpression of gene B drive stress granule formation? | Overexpression cell line with inducible promoter, monitored by live-cell imaging |
| Does a disease-associated variant in gene C alter stress granule properties? | Knock-in of the variant using CRISPR, followed by stress granule assays |
How to Study the nuclear stress granule Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescence microscopy | Granule formation, localization, dynamics | Live-cell imaging of GFP-tagged proteins under stress |
| Proximity labeling (BioID) | Protein-protein interactions | Identifying novel stress granule components |
| RNA-seq | Transcriptome changes | Assessing RNA recruitment to granules |
| CRISPR knockout screen | Gene function | Identifying regulators of stress granule assembly |
| CRISPR point mutation knock-in | Effect of specific mutations | Studying disease-associated variants |
| Autophagy flux assay | Granule clearance | Evaluating NCOA7-mediated clearance |
| Ubiquitination assay | Post-translational modifications | Analyzing TRIM21-mediated G3BP1 ubiquitination |
Imaging-Based Methods
Fluorescence microscopy, including live-cell imaging, is essential for visualizing nuclear stress granule assembly and dynamics. Tagged proteins (e.g., GFP-TIAR) allow real-time tracking of granule formation and disassembly. Super-resolution microscopy can reveal fine structural details.
Proteomics and Interactomics
Mass spectrometry-based proteomics identifies the composition of nuclear stress granules. Proximity labeling (e.g., BioID) with tagged granule proteins reveals interacting partners and dynamic changes under stress.
Transcriptomics and RNA Analysis
RNA sequencing (RNA-seq) and crosslinking immunoprecipitation (CLIP) can determine which RNAs are recruited to nuclear stress granules and how they affect gene expression. Single-cell RNA-seq can reveal heterogeneity in stress granule formation.
Functional Genomics with CRISPR
CRISPR-Cas9 knockout, point mutation, knock-in, and overexpression screens enable systematic dissection of genes regulating nuclear stress granules. Pooled CRISPR screens can identify modifiers of stress granule formation or clearance.
How CRISPR Can Be Used to Study GO:0097165 nuclear stress granule
Knockout
CRISPR knockout of genes such as G3BP1 or TIAR can abolish nuclear stress granule formation, allowing researchers to test their necessity. Knockout cell lines are valuable for studying granule function in stress responses and disease models.
Point Mutation
Point mutation knock-in, such as HMGB1 K177, enables precise interrogation of post-translational modification sites. This approach reveals how specific residues regulate stress granule assembly and dynamics.
Knock-in
Knock-in of tagged proteins (e.g., GFP-TIAR) allows real-time visualization and proteomic analysis of nuclear stress granules. Tagged knock-in models are essential for tracking granule dynamics in live cells.
Overexpression
Overexpression of stress granule components, such as TDP-43 or FUS, can induce granule formation and model neurodegenerative diseases. Overexpression models help study gain-of-function effects and phase separation.
How EDITGENE Supports nuclear stress granule Research
Researchers studying nuclear stress granule-related genes often need to determine whether a candidate gene is causally involved in granule assembly, disassembly, or disease pathogenesis. EDITGENE provides comprehensive CRISPR-based services to accelerate this research, from knockout to knock-in and library screening.
Contact EDITGENE today to design your custom CRISPR model for nuclear stress granule research.
Frequently Asked Questions About nuclear stress granule
What is a nuclear stress granule?
A nuclear stress granule (GO:0097165) is a dense aggregation in the nucleus composed of proteins and RNAs that appears when the cell is under stress.
What genes are involved in nuclear stress granule formation?
Key genes include TIAR, G3BP1, HMGB1, NCOA7, TRIM21, TDP-43, and FUS, among others.
How are nuclear stress granules different from cytoplasmic stress granules?
Nuclear stress granules are located in the nucleus and may have distinct assembly pathways and functions, though they share some protein components with cytoplasmic stress granules.
What diseases are associated with nuclear stress granules?
They are implicated in cancer, neurodegenerative diseases like ALS, aging, and immune responses.
How can CRISPR be used to study nuclear stress granules?
CRISPR knockout, point mutation, knock-in, and overexpression models allow functional dissection of genes regulating nuclear stress granule assembly and clearance.
What methods are used to study nuclear stress granules?
Common methods include fluorescence microscopy, proteomics, RNA-seq, and CRISPR screens.
What is the role of phase separation in nuclear stress granules?
Phase separation of low-complexity domains in RNA-binding proteins drives the formation of membraneless nuclear stress granules.
How are nuclear stress granules cleared?
They are cleared through autophagy-dependent mechanisms and ubiquitination pathways, involving proteins like NCOA7 and TRIM21.
What is the significance of HMGB1 lactylation in stress granules?
Lactylation of HMGB1 at K177 drives nuclear export of TIAR, promoting stress granule formation under hypoxia.
Can nuclear stress granules be targeted therapeutically?
Yes, targeting stress granule assembly or clearance pathways is being explored for cancer and neurodegenerative diseases.
Conclusion
Nuclear stress granules (GO:0097165) are dynamic, membraneless organelles that assemble in the nucleus under stress, playing critical roles in RNA metabolism and cell survival. Their dysregulation is linked to cancer, neurodegeneration, and aging, making them important research targets. Advances in CRISPR-based models and imaging technologies are accelerating our understanding of these granules, with the potential to translate findings into novel therapeutics.
References
- 1. Yang C et al.. 2023. Stress granule homeostasis is modulated by TRIM21-mediated ubiquitination of G3BP1 and autophagy-dependent elimination of stress granules.. Autophagy 19(7):1934-1951 PMID: 36692217
- 2. Dong T et al.. 2025. Stress granule clearance mediated by V-ATPase-interacting protein NCOA7 mitigates ovarian aging.. Nat Aging 5(8):1548-1567 PMID: 40745099
- 3. Zhang K et al.. 2018. Stress Granule Assembly Disrupts Nucleocytoplasmic Transport.. Cell 173(4):958-971.e17 PMID: 29628143
- 4. Li C et al.. 2025. Lactylation of HMGB1 at K177 Drives Nuclear Export of TIAR to Promote Hypoxia-Induced Stress Granule Formation.. Adv Sci (Weinh) 12(41):e04896 PMID: 40788094
- 5. Molliex A et al.. 2015. Phase separation by low complexity domains promotes stress granule assembly and drives pathological fibrillization.. Cell 163(1):123-33 PMID: 26406374
- 6. Chen W et al.. 2022. Allergen protease-activated stress granule assembly and gasdermin D fragmentation control interleukin-33 secretion.. Nat Immunol 23(7):1021-1030 PMID: 35794369
- 7. Hirose T et al.. 2023. A guide to membraneless organelles and their various roles in gene regulation.. Nat Rev Mol Cell Biol 24(4):288-304 PMID: 36424481
- 8. Do TQ et al.. 2020. A Nuclear Stress Pathway that Parallels Cytoplasmic Stress Granule Formation.. iScience 23(11):101664 PMID: 33134894
