GO:0090261 positive regulation of inclusion body assembly: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0090261 describes any process that increases the rate, frequency, or extent of inclusion body assembly, the aggregation and bonding of components into an inclusion body.
• Inclusion bodies are phase-separated, often membraneless compartments that concentrate viral or cellular proteins during stress, infection, or neurodegeneration.
• Positive regulation of inclusion body assembly is driven by multivalent protein-protein and protein-RNA interactions, often involving intrinsically disordered regions and liquid-liquid phase separation.
• Key regulators include stress granule proteins, nucleolar tethering factors, and viral proteins such as grass carp reovirus VP35 that hijack host factors like DHX15.
• Dysregulation of inclusion body assembly is linked to frontotemporal dementia with inclusion body myopathy, Alzheimer's disease, and viral immune evasion.
• CRISPR knockout, knock-in, and overexpression models are essential to dissect causal roles of candidate genes in inclusion body assembly.
Description
Inclusion bodies are intracellular aggregates of proteins, nucleic acids, and other macromolecules that form under conditions of cellular stress, infection, or disease. The Gene Ontology term GO:0090261, positive regulation of inclusion body assembly, captures the processes that enhance the formation of these structures. This term is critical for understanding how cells compartmentalize misfolded proteins, viral replication factories, and stress-responsive ribonucleoprotein granules. Researchers studying neurodegeneration, virology, and proteostasis rely on this ontology term to annotate and interpret experimental data on aggregate formation. The QuickGO definition states that it is any process that increases the rate, frequency, or extent of inclusion body assembly, where inclusion body assembly is the aggregation, arrangement and bonding together of a set of components to form an inclusion body. This definition underscores the dynamic and regulated nature of inclusion body formation, distinguishing it from passive aggregation. Understanding positive regulation of inclusion body assembly has broad implications for antiviral immunity, neurodegenerative disease mechanisms, and the development of therapeutic strategies targeting protein aggregation.
positive regulation of inclusion body assembly At A Glance
| GO ID | GO:0090261 |
|---|---|
| GO term | positive regulation of inclusion body assembly |
| Ontology | biological_process |
| Synonym | none |
| Major function | Enhances the formation of inclusion bodies, which are aggregates of proteins and nucleic acids often involved in stress responses, viral replication, and neurodegeneration |
| Related process | Inclusion body assembly (GO:0016236) and its regulation |
| Cellular context | Cytoplasm, nucleus, and membraneless organelles such as stress granules and nucleoli |
| Disease relevance | Frontotemporal dementia with inclusion body myopathy, Alzheimer's disease, viral infections |
| Experimental models | CRISPR knockout, knock-in, overexpression cell lines, and viral infection models |
What Is GO:0090261?
GO:0090261, positive regulation of inclusion body assembly, is a biological process term defined as any process that increases the rate, frequency, or extent of inclusion body assembly. Inclusion body assembly itself is the aggregation, arrangement and bonding together of a set of components to form an inclusion body. This term encompasses molecular events that promote the nucleation, growth, and stabilization of inclusion bodies, which are often phase-separated compartments enriched in specific proteins and RNAs.
Why Is positive regulation of inclusion body assembly Important in Cell Biology?
Positive regulation of inclusion body assembly is important because inclusion bodies are central to cellular responses to stress, infection, and protein misfolding. They serve as hubs for viral replication, sites of protein quality control, and precursors to pathological aggregates in neurodegenerative diseases. Understanding the positive regulators of this process can reveal therapeutic targets for conditions such as frontotemporal dementia, inclusion body myopathy, and viral infections.
• Inclusion bodies are formed during viral infections and can serve as replication factories for positive-strand RNA viruses.
• Stress granules, a type of inclusion body, regulate stress-induced paraspeckle assembly and are dynamically controlled.
• Dysregulation of inclusion body assembly is linked to frontotemporal dementia with inclusion body myopathy.
• Alzheimer's disease involves amyloid-beta aggregation, and humanin can counteract amyloid-beta oligomer toxicity, highlighting inclusion body regulation.
• Promyelocytic leukemia protein (PML) is involved in oxidative stress and metabolism, and PML nuclear bodies are inclusion-like structures.
• Nucleolus-tethering systems can be used to study inclusion body assembly and protein aggregation.
• CRISPR screens can identify positive regulators of inclusion body assembly, aiding drug target discovery.
• Understanding inclusion body assembly can inform strategies to enhance antiviral immunity or prevent neurodegeneration.
• Inclusion bodies are used in biotechnology for protein production, and their regulation can be optimized.
• Phase separation is a key mechanism in inclusion body assembly, and its regulation is an active research area.
What Happens During positive regulation of inclusion body assembly?
Nucleation and Phase Separation
In simple terms: The process starts when certain proteins and RNAs come together to form tiny droplets, like oil separating in water.
Positive regulation of inclusion body assembly often begins with liquid-liquid phase separation (LLPS), driven by multivalent interactions among intrinsically disordered regions of proteins and RNA molecules. This nucleation step is enhanced by factors that increase local concentration or valency, such as stress granule proteins and viral proteins like grass carp reovirus VP35, which hijacks DHX15 into phase-separated inclusion bodies. The nucleolus-tethering system (NoTS) can artificially induce inclusion body formation, demonstrating that tethering to specific compartments can positively regulate assembly.
Recruitment of Components
In simple terms: Once the seed is formed, more proteins and RNAs are recruited into the growing inclusion body.
Following nucleation, additional components are recruited to the inclusion body. This recruitment is positively regulated by interactions with scaffolding proteins and RNAs. For example, stress granules regulate stress-induced paraspeckle assembly, indicating cross-talk between different inclusion bodies. Viral proteins can redirect host factors, such as DHX15, into inclusion bodies to evade antiviral immunity. The presence of specific domains, like the nucleolar localization signals in NoTS, can enhance recruitment.
Maturation and Stabilization
In simple terms: The inclusion body matures and becomes more stable, often transitioning from liquid-like to solid-like states.
Positive regulation also encompasses processes that stabilize and mature inclusion bodies. This can involve post-translational modifications, such as methylation, which can affect protein interactions. In the context of disease, proteins like valosin-containing protein (VCP) are implicated in inclusion body myopathy, and mutations in VCP can alter inclusion body dynamics. The maturation step is critical for the function of inclusion bodies in viral replication and stress responses.
Regulation by Stress and Signaling Pathways
In simple terms: Cellular stress and signaling pathways can turn up the volume on inclusion body formation.
Various stress conditions, including oxidative stress and viral infection, positively regulate inclusion body assembly. Promyelocytic leukemia protein (PML) is at the crossroad of oxidative stress and metabolism, and PML nuclear bodies are inclusion-like structures that respond to stress. Transmembrane redox regulation can control genome replication functions in positive-strand RNA viruses, which often form inclusion bodies. Additionally, stress granules, which are themselves inclusion bodies, can regulate the assembly of other inclusion bodies like paraspeckles.
Key Genes Involved in GO:0090261 positive regulation of inclusion body assembly
The following genes and proteins have been experimentally implicated in positive regulation of inclusion body assembly or in the formation of inclusion bodies.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DHX15 | RNA helicase hijacked by viral VP35 into phase-separated inclusion bodies | Viral immune evasion, inclusion body formation |
| VCP | Valosin-containing protein, involved in protein quality control and inclusion body myopathy | Frontotemporal dementia, inclusion body myopathy |
| PML | Promyelocytic leukemia protein, forms nuclear bodies and responds to oxidative stress | Oxidative stress, metabolism, inclusion-like structures |
| G3BP1 | Stress granule marker, involved in phase separation | Stress granule and inclusion body assembly |
| NONO | Paraspeckle protein, regulated by stress granules | Stress-induced paraspeckle assembly |
| FUS | RNA-binding protein, forms inclusions in neurodegeneration | Amyotrophic lateral sclerosis, inclusion body formation |
| TDP-43 | RNA-binding protein, major component of inclusions in ALS and FTD | Neurodegeneration, inclusion body pathology |
| HTT | Huntingtin, forms inclusion bodies in Huntington's disease | Polyglutamine diseases, inclusion body assembly |
| APP | Amyloid precursor protein, involved in amyloid-beta aggregation | Alzheimer's disease, inclusion body formation |
| MAPT | Tau protein, forms neurofibrillary tangles | Tauopathies, inclusion body assembly |
| SNCA | Alpha-synuclein, forms Lewy bodies | Parkinson's disease, inclusion body formation |
| SOD1 | Superoxide dismutase 1, forms inclusions in ALS | Amyotrophic lateral sclerosis, inclusion body assembly |
| ATXN1 | Ataxin-1, forms nuclear inclusions in spinocerebellar ataxia | Polyglutamine diseases, inclusion body formation |
| TIA1 | Stress granule protein, involved in phase separation | Stress granule and inclusion body assembly |
| HNRNPA1 | RNA-binding protein, forms inclusions in myopathy | Inclusion body myopathy, phase separation |
| OPTN | Optineurin, involved in autophagy and inclusion body clearance | Neurodegeneration, inclusion body regulation |
| SQSTM1 | p62, cargo receptor for autophagy, present in inclusion bodies | Protein aggregation, inclusion body clearance |
How Is positive regulation of inclusion body assembly Regulated?
Positive regulation of inclusion body assembly is controlled by multiple signaling pathways and stress responses. Oxidative stress can promote the formation of PML nuclear bodies, which are inclusion-like structures. Viral infection can trigger the assembly of inclusion bodies that serve as replication factories, and viral proteins like VP35 actively hijack host factors such as DHX15 to enhance this process. Stress granules, which are themselves inclusion bodies, can regulate the assembly of paraspeckles under stress conditions. Additionally, the nucleolus-tethering system (NoTS) can be used to artificially induce inclusion body formation, demonstrating that tethering to specific subcellular compartments can positively regulate assembly. Post-translational modifications, such as methylation, may also influence inclusion body assembly by altering protein interactions.
positive regulation of inclusion body assembly and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| VCP | Frontotemporal dementia with inclusion body myopathy | Knock-in of patient mutations in cell lines |
| APP | Alzheimer's disease | Overexpression of mutant APP in neurons |
| SNCA | Parkinson's disease | Knock-in of A53T mutation in iPSCs |
| TDP-43 | Amyotrophic lateral sclerosis | Knockout or overexpression of TDP-43 in motor neurons |
| DHX15 | Viral immune evasion | Knockout in fish cells infected with grass carp reovirus |
Neurodegenerative Diseases
Inclusion bodies are a hallmark of many neurodegenerative diseases. In frontotemporal dementia with inclusion body myopathy, mutations in VCP lead to abnormal inclusion body formation and impaired protein degradation. Alzheimer's disease is characterized by amyloid-beta plaques and tau tangles, which are inclusion bodies; humanin can counteract amyloid-beta oligomer toxicity, suggesting a regulatory role. Parkinson's disease involves Lewy bodies composed of alpha-synuclein, and amyotrophic lateral sclerosis features TDP-43 and FUS inclusions.
Viral Infections
Many positive-strand RNA viruses induce inclusion bodies that serve as replication factories. For example, grass carp reovirus VP35 hijacks DHX15 into phase-separated inclusion bodies to evade host antiviral immunity. Transmembrane redox regulation is critical for genome replication functions in these viruses, and inclusion bodies provide a platform for replication. Understanding how viruses positively regulate inclusion body assembly can inform antiviral strategies.
Cancer and Metabolic Disorders
PML nuclear bodies, which are inclusion-like structures, are involved in oxidative stress and metabolism and have roles in cancer. Dysregulation of inclusion body assembly can affect cellular metabolism and contribute to tumorigenesis. Additionally, inclusion bodies can sequester tumor suppressors or oncoproteins, influencing cancer progression.
From positive regulation of inclusion body assembly-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X positively regulate inclusion body assembly? | CRISPR knockout cell line followed by inclusion body quantification |
| Does a specific point mutation affect inclusion body formation? | Point mutation knock-in via CRISPR |
| Does tagging the protein affect its localization to inclusion bodies? | Tagged knock-in with fluorescent protein |
| Does overexpression of gene X enhance inclusion body assembly? | Doxycycline-inducible overexpression cell line |
| Which genes are essential for inclusion body assembly? | Genome-wide CRISPR library screening |
| How does viral protein VP35 hijack host factors? | Overexpression of VP35 in host cells and proteomics |
How to Study the positive regulation of inclusion body assembly Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescence microscopy | Inclusion body number, size, and localization | Visualizing inclusion bodies in live cells |
| Immunoprecipitation-mass spectrometry | Protein composition of inclusion bodies | Identifying novel components |
| CRISPR knockout screening | Genes required for inclusion body assembly | Discovery of positive regulators |
| Filter trap assay | Insoluble protein aggregates | Quantifying inclusion body formation |
| FRAP | Dynamics of inclusion body components | Assessing liquid-like vs solid-like properties |
| RNA-seq | Transcriptional changes during inclusion body formation | Identifying pathways involved |
| Proximity ligation assay | Protein-protein interactions in inclusion bodies | Detecting interactions in situ |
Fluorescence Microscopy and Live Imaging
Fluorescence microscopy is used to visualize inclusion bodies in cells. Tagging proteins with fluorescent proteins, such as GFP, allows tracking of inclusion body assembly in real time. Live imaging can capture the dynamics of phase separation and recruitment of components.
Proteomics and Interactomics
Proteomic approaches, including immunoprecipitation coupled with mass spectrometry, can identify components of inclusion bodies and their interactors. For example, DHX15 was identified as a host factor hijacked by viral VP35 into inclusion bodies. This method helps elucidate the molecular composition and regulation of inclusion bodies.
CRISPR Screening
Genome-wide CRISPR knockout or activation screens can identify positive regulators of inclusion body assembly. Cells are infected or stressed, and inclusion body formation is quantified to identify genes whose loss or gain affects the process.
Biochemical Fractionation and Aggregation Assays
Biochemical fractionation separates soluble and insoluble fractions to quantify inclusion body formation. Aggregation assays, such as filter trap assays, can detect large aggregates. These methods are useful for studying disease-associated proteins like VCP and TDP-43.
How CRISPR Can Be Used to Study GO:0090261 positive regulation of inclusion body assembly
Knockout
CRISPR knockout is used to delete candidate genes and assess their requirement for inclusion body assembly. For example, knocking out DHX15 can test its role in viral inclusion body formation. Knockout of stress granule genes can reveal their impact on paraspeckle assembly.
Point Mutation
Point mutations identified in patients, such as those in VCP, can be introduced via CRISPR to study their effects on inclusion body assembly and disease pathogenesis. This allows precise modeling of genetic variants.
Knock-in
Knock-in of fluorescent tags or epitope tags enables visualization and purification of inclusion body components. Tagged knock-in of proteins like G3BP1 allows live tracking of stress granules. Knock-in of disease mutations can create isogenic models.
Overexpression
Overexpression of wild-type or mutant proteins can drive inclusion body formation. For example, overexpression of viral VP35 induces phase-separated inclusion bodies. Overexpression of alpha-synuclein or tau can model neurodegenerative inclusions.
How EDITGENE Supports positive regulation of inclusion body assembly Research
Researchers studying positive regulation of inclusion body assembly-related genes often need to determine whether a candidate gene is causally involved in the process or is merely a bystander. EDITGENE provides comprehensive CRISPR-based services to generate knockout, point mutation, knock-in, and overexpression cell models, as well as library screening and bioinformatics support, to accelerate discovery in this field.
Contact EDITGENE today to design your custom CRISPR model for positive regulation of inclusion body assembly research.
Frequently Asked Questions About positive regulation of inclusion body assembly
What is GO:0090261?
GO:0090261 is the Gene Ontology term for positive regulation of inclusion body assembly, defined as any process that increases the rate, frequency, or extent of inclusion body assembly.
What are inclusion bodies?
Inclusion bodies are intracellular aggregates of proteins, RNAs, and other molecules that form under stress, infection, or disease conditions.
What genes are involved in positive regulation of inclusion body assembly?
Genes such as DHX15, VCP, PML, G3BP1, and viral proteins like VP35 have been implicated in inclusion body assembly.
How is inclusion body assembly regulated?
It is regulated by phase separation, stress signaling, viral proteins, and post-translational modifications.
What diseases are associated with inclusion body assembly?
Neurodegenerative diseases like frontotemporal dementia, Alzheimer's, Parkinson's, and viral infections are associated with inclusion bodies.
What methods are used to study inclusion body assembly?
Fluorescence microscopy, proteomics, CRISPR screening, and biochemical assays are commonly used.
Can CRISPR be used to study inclusion body assembly?
Yes, CRISPR knockout, knock-in, and overexpression models are powerful tools to dissect gene function in inclusion body assembly.
What is the role of phase separation in inclusion body assembly?
Phase separation drives the formation of membraneless compartments that mature into inclusion bodies.
How do viruses hijack inclusion body assembly?
Viruses like grass carp reovirus use proteins such as VP35 to recruit host factors like DHX15 into inclusion bodies for replication and immune evasion.
What cell models are available for inclusion body research?
Knockout, point mutation, knock-in, and overexpression cell lines can be generated via CRISPR for inclusion body studies.
Conclusion
Positive regulation of inclusion body assembly (GO:0090261) is a fundamental biological process with broad implications for virology, neurobiology, and cell stress responses. Understanding its molecular mechanisms and key regulators can lead to new therapeutic strategies for neurodegenerative diseases and viral infections. EDITGENE offers a full suite of CRISPR services to support research in this area, from knockout and knock-in models to library screening and bioinformatics.
References
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- 3. Guinto JB et al.. 2007. Valosin-containing protein and the pathogenesis of frontotemporal dementia associated with inclusion body myopathy.. Acta Neuropathol 114(1):55-61 PMID: 17457594
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- 7. Romeo M et al.. 2017. Humanin Specifically Interacts with Amyloid-β Oligomers and Counteracts Their in vivo Toxicity.. J Alzheimers Dis 57(3):857-871 PMID: 28282805
- 8. Zeng Y et al.. 2023. Natural methylation epialleles correlate with gene expression in maize.. Genetics 225(2) PMID: 37556604
