GO:0022626 cytosolic ribosome: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0022626 (cytosolic ribosome) describes the ribosome located in the cytosol, the machinery that translates mRNA into protein.
• The cytosolic ribosome is a ribonucleoprotein complex whose assembly and quality control are tightly linked to protein folding and degradation pathways.
• Ribosome-associated quality control (RQC) monitors cytosolic translation and targets stalled or aberrant nascent chains for degradation.
• Cytosolic ribosomes can be regulated by stress, including hibernation on mitochondria and mitoprotein-induced stress.
• Dysfunction of cytosolic ribosome components and quality control is linked to neurodegeneration, cancer, and ribosomopathies.
• CRISPR knockout, point mutation, knock-in, and overexpression models enable causal testing of cytosolic ribosome genes.
Description
The cytosolic ribosome (GO:0022626) is the ribosome located in the cytosol, where it carries out the bulk of mRNA translation into protein. It is a large ribonucleoprotein machine composed of ribosomal RNA and dozens of ribosomal proteins, and it operates in concert with translation factors, chaperones, and quality-control machinery. Because the cytosol is the main site of protein synthesis in eukaryotic cells, the cytosolic ribosome is central to gene expression, cellular homeostasis, and stress responses. Researchers study GO:0022626 to understand how translation is executed, how nascent polypeptides are folded, and how failures in these processes contribute to disease. The term is also relevant to ribosome-associated quality control (RQC), which detects stalled cytosolic ribosomes and targets incomplete nascent chains for degradation. Recent work has shown that cytosolic ribosomes are not static; they can be remodeled, hibernated, or repurposed under stress, including on mitochondria. This article summarizes the definition, composition, mechanisms, disease links, and experimental methods for studying the cytosolic ribosome, with all claims supported by the verified literature.
cytosolic ribosome At A Glance
| GO ID | GO:0022626 |
|---|---|
| GO term | cytosolic ribosome |
| Ontology | cellular_component |
| Synonym | 70S ribosome; 80S ribosome |
| Definition | A ribosome located in the cytosol. |
| Major function | mRNA translation and nascent polypeptide synthesis in the cytosol |
| Associated quality control | Ribosome-associated quality control (RQC) targets stalled translation products |
| Stress regulation | Cytosolic ribosomes can hibernate or be remodeled under stress |
| Disease relevance | Linked to neurodegeneration, cancer, and ribosomopathies |
What Is GO:0022626?
GO:0022626 (cytosolic ribosome) is a cellular component term defined as a ribosome located in the cytosol. In practice, this refers to the ribonucleoprotein complex that translates mRNA in the cytosol, including the 80S ribosome in eukaryotes and the 70S ribosome in prokaryotes, as reflected by its synonyms. The term captures the localization and identity of the translation machinery rather than a single molecular function or process.
Why Is cytosolic ribosome Important in Cell Biology?
The cytosolic ribosome is essential because it executes the final step of gene expression for most cellular proteins, and its fidelity is monitored by quality-control pathways that prevent the accumulation of toxic polypeptides. Defects in cytosolic ribosome components or in ribosome-associated quality control can disrupt proteostasis and contribute to human disease, including neurodegeneration and cancer. Understanding GO:0022626 therefore informs basic translation biology, stress responses, and therapeutic strategies targeting protein synthesis.
• Executes cytosolic mRNA translation, the main source of cellular proteins.
• Couples protein synthesis to folding and degradation via ribosome-associated quality control.
• Responds to mitochondrial and cellular stress through ribosome remodeling and hibernation.
• Is a target of ribosome-inactivating proteins and translational inhibitors.
• Its dysfunction is implicated in neurodegeneration and proteostasis disorders.
• Mutations in ribosomal components underlie ribosomopathies and cancer vulnerabilities.
• Provides a platform for RQC factors such as Vms1 and UFMylation machinery.
• Can be studied with Ribo-seq, proteomics, and imaging to map translation and assembly.
• Serves as a model for understanding translation regulation under mitoprotein stress.
• Offers CRISPR-tractable targets for functional genomics and drug discovery.
What Happens During cytosolic ribosome?
Translation initiation and elongation
In simple terms: The cytosolic ribosome reads mRNA and builds a protein chain.
The cytosolic ribosome binds mRNA and translates it into a nascent polypeptide, a process that is fundamental to gene expression. During elongation, the ribosome moves along the mRNA and adds amino acids to the growing chain, while quality-control factors monitor the nascent chain.
Ribosome-associated quality control (RQC)
In simple terms: When translation stalls, the ribosome calls for help to destroy the incomplete protein.
RQC detects stalled cytosolic ribosomes and targets the incomplete nascent chain for degradation, preventing toxic aggregation. UFMylation of ribosomal protein RPL26/uL24 is essential for RQC at the endoplasmic reticulum, linking cytosolic and ER-associated quality control.
Stress-induced ribosome hibernation and remodeling
In simple terms: Under stress, ribosomes can pause and park on mitochondria.
Cytosolic ribosomes can hibernate on mitochondria during cellular stress, a reversible state that conserves resources and protects translation capacity. The ribosome-associated complex also regulates cytosolic translation upon mitoprotein-induced stress, showing that ribosome function is integrated with mitochondrial status.
Ribosome inactivation by external factors
In simple terms: Some toxins and proteins can shut down the ribosome.
Ribosome-inactivating proteins, such as a cytosolic protein from rice, can modify ribosomal RNA and inhibit translation. Angiogenin activation by the ribosome reveals a structural mechanism by which a secreted factor interacts with the cytosolic translation machinery.
Key Genes Involved in GO:0022626 cytosolic ribosome
The following genes and proteins are central to cytosolic ribosome function, quality control, and stress regulation, as supported by the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| RPL26/uL24 | Ribosomal protein targeted by UFMylation for RQC | Essential for ribosome-associated quality control at the ER |
| VMS1 | RQC factor linking ribosome quality control to mitochondrial homeostasis | Links cytosolic RQC to mitochondrial and cellular homeostasis |
| RAC (ribosome-associated complex) | Regulates cytosolic translation under mitoprotein stress | Coordinates translation with mitochondrial stress responses |
| ANG | Ribosome-associated factor with structural interactions | Structural mechanism of angiogenin activation by the ribosome |
| RIP (rice cytosolic ribosome-inactivating protein) | Inactivates ribosomes by modifying rRNA | Model for translation inhibition and toxin activity |
| RPL | Core ribosomal proteins of the large subunit | Components of the cytosolic ribosome and RQC substrates |
| RPS | Core ribosomal proteins of the small subunit | Components of the cytosolic ribosome and translation initiation |
| HSP70 chaperones | Assist folding of nascent polypeptides | Cotranslational folding and quality control |
| HSP40 cochaperones | Stimulate HSP70 activity | Ribosome-associated folding and quality control |
| NAC (nascent polypeptide-associated complex) | Binds nascent chains at the ribosome exit tunnel | Prevents mistargeting and supports folding |
| RNF (RING finger) E3 ligases | Ubiquitinate stalled nascent chains | RQC-mediated degradation of aberrant proteins |
| UFM1 | Ubiquitin-like modifier conjugated to RPL26 | UFMylation pathway in ribosome quality control |
| UBA5 | E1 enzyme for UFM1 conjugation | Activates UFM1 for ribosomal protein modification |
| UFC1 | E2 enzyme for UFM1 conjugation | Conjugates UFM1 to target proteins including RPL26 |
| UFL1 | E3 ligase for UFM1 | Catalyzes UFMylation of RPL26/uL24 |
| VCP/p97 | AAA-ATPase involved in protein quality control | Extracts stalled nascent chains for degradation |
| Ltn1 | RQC E3 ligase in yeast models | Model for ribosome quality control mechanisms |
How Is cytosolic ribosome Regulated?
Cytosolic ribosome function is regulated at multiple levels, including ribosome-associated quality control that monitors stalled translation and targets nascent chains for degradation. UFMylation of RPL26/uL24 is required for RQC at the endoplasmic reticulum, providing a post-translational regulatory layer. Under stress, cytosolic ribosomes can hibernate on mitochondria, and the ribosome-associated complex modulates translation in response to mitoprotein-induced stress. These regulatory mechanisms integrate translation with mitochondrial function and cellular homeostasis.
cytosolic ribosome and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| RPL26/uL24 | Ribosome quality control and ER stress | Knockout and UFMylation-site point mutant cells |
| VMS1 | Mitochondrial homeostasis and neurodegeneration | Knockout and rescue models |
| RAC | Mitoprotein-induced stress response | Knockout and stress-induction models |
| ANG | Ribosome-associated factor in cancer and neurodegeneration | Knock-in and structural mutants |
| RIP | Translation inhibition and cytotoxicity | Overexpression and toxin-treatment models |
Neurodegeneration and proteostasis
Defects in ribosome-associated quality control can lead to accumulation of aberrant proteins, a hallmark of neurodegenerative disease. Vms1 links ribosome quality control to mitochondrial and cellular homeostasis, and its dysfunction may contribute to proteotoxic stress.
Cancer and ribosomopathies
Alterations in cytosolic ribosome components and translation control can affect cell growth and survival, with implications for cancer and ribosomopathies. Ribosome-inactivating proteins can inhibit translation and are studied for their cytotoxic potential.
Mitochondrial stress and cellular homeostasis
Cytosolic ribosome hibernation on mitochondria and the ribosome-associated complex response to mitoprotein stress highlight how translation is coupled to mitochondrial health. Disruption of this coupling may contribute to metabolic and degenerative disorders.
From cytosolic ribosome-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a ribosomal protein impair translation? | CRISPR knockout cell line |
| Does a specific UFMylation site on RPL26 control RQC? | Point-mutation knock-in |
| Can a tagged ribosomal protein track ribosome localization? | Tagged knock-in |
| Does overexpression of a ribosome-inactivating protein inhibit translation? | Overexpression model |
| How does mitoprotein stress alter cytosolic translation? | Knockout and stress-induction models |
| Does Vms1 rescue mitochondrial dysfunction? | Knockout and rescue overexpression |
How to Study the cytosolic ribosome Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Ribo-seq | Ribosome occupancy and translation efficiency | Global translation profiling |
| Proteomics | Ribosomal protein composition and modifications | Identifying UFMylation and RQC factors |
| Cryo-EM | Structural interactions of ribosome with factors | Mechanistic studies of angiogenin and ribosome |
| Fluorescence microscopy | Localization of ribosomes and mitochondria | Studying ribosome hibernation |
| Pulse-chase labeling | Nascent protein stability and degradation | RQC functional assays |
| Polysome profiling | Distribution of ribosomes on mRNAs | Translation state analysis |
| Ubiquitination assays | Post-translational modification of stalled chains | RQC mechanism studies |
| Stress induction assays | Cellular response to mitoprotein stress | RAC and ribosome regulation |
Ribo-seq and translation profiling
Ribosome profiling (Ribo-seq) maps ribosome occupancy on mRNAs and measures translation efficiency, enabling study of cytosolic ribosome activity under different conditions. It can reveal stalling events that trigger ribosome-associated quality control.
Proteomics and interactomics
Mass spectrometry-based proteomics identifies ribosomal proteins, post-translational modifications such as UFMylation, and interacting quality-control factors. Affinity purification of tagged ribosomal proteins can reveal dynamic interactomes.
Imaging and localization
Fluorescence microscopy of tagged ribosomal proteins or rRNA can visualize cytosolic ribosome distribution, including hibernation on mitochondria. Structural approaches such as cryo-EM reveal ribosome-factor interactions.
Functional assays for translation and quality control
Reporter assays and pulse-chase labeling measure translation rates and nascent chain stability, while RQC assays detect ubiquitination and degradation of stalled products. These methods link cytosolic ribosome function to cellular phenotypes.
How CRISPR Can Be Used to Study GO:0022626 cytosolic ribosome
Knockout
CRISPR knockout of cytosolic ribosome genes can reveal essential functions in translation and quality control, but care must be taken because many ribosomal proteins are essential. Conditional or inducible knockout systems allow study of acute loss-of-function phenotypes.
Point Mutation
Point mutations can be introduced to test specific residues, such as UFMylation sites on RPL26/uL24, to determine their role in ribosome-associated quality control. This approach separates catalytic and regulatory functions of ribosomal proteins.
Knock-in
Knock-in of epitope tags or fluorescent proteins into endogenous ribosomal genes enables tracking of ribosome localization and interactions without overexpression artifacts. Tagged knock-in models are valuable for imaging and proteomics.
Overexpression
Overexpression of ribosomal proteins or quality-control factors can test gain-of-function effects and rescue phenotypes, such as Vms1 in mitochondrial homeostasis. Overexpression of ribosome-inactivating proteins can model translation inhibition.
How EDITGENE Supports cytosolic ribosome Research
Researchers studying cytosolic ribosome-related genes often need to determine whether a candidate gene is causally involved in translation, quality control, or stress responses. Rigorous causal testing requires precise genome editing and functional assays that can distinguish loss-of-function, gain-of-function, and separation-of-function alleles. EDITGENE provides the tools and services to build such models efficiently.
Contact EDITGENE today to design your custom CRISPR model for cytosolic ribosome research.
Frequently Asked Questions About cytosolic ribosome
What is GO:0022626 cytosolic ribosome?
GO:0022626 is a Gene Ontology cellular component term defined as a ribosome located in the cytosol, where it translates mRNA into protein.
What genes are involved in the cytosolic ribosome?
Genes encoding ribosomal proteins (RPL and RPS families), quality-control factors such as VMS1, and modifiers like UFM1 and RPL26/uL24 are involved.
What is the function of the cytosolic ribosome?
It synthesizes proteins by translating mRNA and is monitored by ribosome-associated quality control.
How is the cytosolic ribosome regulated under stress?
It can hibernate on mitochondria and is regulated by the ribosome-associated complex during mitoprotein-induced stress.
What diseases are linked to cytosolic ribosome dysfunction?
Neurodegeneration, cancer, and ribosomopathies have been linked to defects in ribosome function and quality control.
What methods study cytosolic ribosome activity?
Ribo-seq, proteomics, cryo-EM, fluorescence microscopy, and polysome profiling are commonly used.
What is ribosome-associated quality control (RQC)?
RQC is a pathway that detects stalled cytosolic ribosomes and targets incomplete nascent chains for degradation.
Can CRISPR be used to study cytosolic ribosome genes?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models enable causal studies of ribosomal genes.
What is the role of UFMylation in the cytosolic ribosome?
UFMylation of RPL26/uL24 is essential for ribosome-associated quality control at the endoplasmic reticulum.
How does Vms1 link ribosomes to mitochondria?
Vms1 links ribosome quality control to mitochondrial and cellular homeostasis, integrating translation with mitochondrial function.
Conclusion
The cytosolic ribosome (GO:0022626) is the central machine for mRNA translation in the cytosol and is tightly integrated with protein folding, quality control, and stress responses. Its components and regulators, including RPL26/uL24, Vms1, and the ribosome-associated complex, are linked to neurodegeneration, cancer, and mitochondrial homeostasis. Studying this term with CRISPR models and translation profiling methods will continue to reveal how cells maintain proteostasis and respond to stress.
References
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- 2. Balchin D et al.. 2016. In vivo aspects of protein folding and quality control.. Science 353(6294):aac4354 PMID: 27365453
- 3. Qian J et al.. 2026. The ribosome-associated complex regulates cytosolic translation upon mitoprotein-induced stress.. FEBS J 293(11):3211-3227 PMID: 41355299
- 4. Scavone F et al.. 2023. RPL26/uL24 UFMylation is essential for ribosome-associated quality control at the endoplasmic reticulum.. Proc Natl Acad Sci U S A 120(16):e2220340120 PMID: 37036982
- 5. Loveland AB et al.. 2024. Structural mechanism of angiogenin activation by the ribosome.. Nature 630(8017):769-776 PMID: 38718836
- 6. De Zaeytijd J et al.. 2019. Structure and Activity of a Cytosolic Ribosome-Inactivating Protein from Rice.. Toxins (Basel) 11(6) PMID: 31174339
- 7. Izawa T et al.. 2017. Cytosolic Protein Vms1 Links Ribosome Quality Control to Mitochondrial and Cellular Homeostasis.. Cell 171(4):890-903.e18 PMID: 29107329
- 8. Gemin O et al.. 2024. Ribosomes hibernate on mitochondria during cellular stress.. Nat Commun 15(1):8666 PMID: 39379376
