GO:0010040 response to iron(II) ion: Cellular Iron Sensing, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0010040 (response to iron(II) ion) describes any process that changes a cell or organism's state or activity in response to an iron(II) (ferrous) ion stimulus.
• Iron(II) is the reduced, soluble form of iron that drives redox chemistry, labile iron pools, and signaling, making its sensing and detoxification central to cell physiology.
• Dysregulated iron(II) handling is linked to vascular endothelial injury, impaired immune responses, and cancer immunotherapy resistance.
• Analytical and reporter systems, including genetically encoded fluorescent reporters and iron(II)-selective clathrochelates, allow real-time tracking of intracellular labile iron.
• Iron(II) also participates in environmental and biotechnological responses, such as toxin synthesis and ion transport in cyanobacteria.
• CRISPR knockout, point-mutation, knock-in, and overexpression models are essential to test causal roles of iron(II)-responsive genes in disease and cell biology.
Description
GO:0010040, response to iron(II) ion, is a biological process Gene Ontology term defined as any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an iron(II) ion stimulus. Iron(II), or ferrous iron, is the reduced and highly bioavailable form of iron that participates in redox reactions, oxygen transport, and cellular signaling. Because iron(II) can catalyze Fenton chemistry and generate reactive oxygen species, cells must constantly sense and respond to its availability. This term therefore captures a broad set of physiological responses, from ion transport regulation to changes in gene expression and protein stability. Researchers study GO:0010040 because iron(II) homeostasis is fundamental to health and disease. Acute exposure to iron(II) impairs vascular endothelial structure and function, highlighting the sensitivity of the vasculature to ferrous iron overload. In cancer immunology, inhibiting neutrophil extracellular trap formation through iron regulation can enhance immunotherapy, showing that iron(II)-responsive pathways shape immune cell behavior. In environmental systems, exposure to 5,4'-dihydroxyflavone down-regulates iron/zinc ion transport and toxin synthesis in Microcystis aeruginosa, linking iron(II) responses to microbial ecology and toxin production. Methodologically, the field has advanced through iron(II)-selective chemical probes and genetically encoded reporters. Iron(II) clathrochelates functionalized with carboxyalkylsulfide groups can sense proteins via induced circular dichroism responses, while genetically encoded fluorescent reporter systems based on protein stability enable tracking of intracellular labile iron. These tools, combined with CRISPR-based genetic models, allow researchers to dissect the causal architecture of the response to iron(II) ion.
response to iron(II) ion At A Glance
| GO ID | GO:0010040 |
|---|---|
| GO term | response to iron(II) ion |
| Ontology | biological_process |
| Synonym | response to iron(II) |
| Major function | Cellular and organismal adaptation to ferrous iron (iron(II)) stimuli, including changes in ion transport, gene expression, and protein stability |
| Definition source | QuickGO definition: Any process that results in a change in state or activity of a cell or an organism as a result of an iron(II) ion stimulus |
| Related stimuli | Iron(II) exposure, labile iron pools, ferrous iron overload |
| Representative assays | Genetically encoded fluorescent reporters, iron(II)-selective clathrochelates, capillary electrophoresis |
| Disease relevance | Vascular endothelial dysfunction, cancer immunotherapy, microbial toxin regulation |
What Is GO:0010040?
In simple terms, GO:0010040 describes how a cell or organism reacts when it encounters iron(II) ions. According to the QuickGO definition, it is any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an iron(II) ion stimulus. This includes changes in ion transport, gene expression, protein stability, and metabolic activity that help the cell adapt to ferrous iron availability or toxicity.
Why Is response to iron(II) ion Important in Cell Biology?
GO:0010040 matters because iron(II) is both essential and dangerous: it supports redox chemistry and oxygen transport but can drive oxidative damage when uncontrolled. Understanding how cells respond to iron(II) helps explain diseases ranging from vascular injury to cancer and informs the development of iron-targeted therapies and diagnostics. It also underpins environmental and biotechnological applications, such as controlling toxin synthesis in cyanobacteria.
• Iron(II) is the soluble, redox-active form of iron that cells must sense and buffer to avoid oxidative stress.
• Acute iron(II) exposure impairs vascular endothelial structure and function, linking the response to cardiovascular injury.
• Iron regulation of neutrophil extracellular traps can enhance cancer immunotherapy, showing immune relevance.
• In Microcystis aeruginosa, iron(II)-related ion transport changes accompany altered toxin synthesis, with ecological implications.
• Genetically encoded reporters enable real-time tracking of intracellular labile iron, advancing mechanistic studies.
• Iron(II)-selective clathrochelates provide chemical tools for protein sensing and iron detection.
• Capillary electrophoresis with iron(II)-1,10-phenanthroline complexes offers sensitive iron quantification.
• Gold nanoparticle conjugates with iron(II) Prussian Blue analogues enable aptamer-based biosensing.
• Carbon quantum dot fluorometric assays exploit iron(II) oxidation for nitrite detection.
• CRISPR models allow causal testing of genes involved in iron(II) responses in disease contexts.
What Happens During response to iron(II) ion?
Iron(II) sensing and labile iron pool detection
In simple terms: The cell first notices that iron(II) levels have changed.
Cells detect iron(II) through labile iron pools and specialized sensor systems. Genetically encoded fluorescent reporter systems based on protein stability can track intracellular labile iron in real time, revealing dynamic changes in iron(II) availability. Iron(II) clathrochelates functionalized with carboxyalkylsulfide groups can sense proteins via induced circular dichroism, providing chemical tools to probe iron(II)-protein interactions. These sensing mechanisms initiate downstream responses that alter cell state or activity.
Transcriptional and post-transcriptional regulation of iron transport
In simple terms: The cell changes which transport and storage genes are turned on or off.
A major response to iron(II) is altered expression of ion transport and storage genes. In Microcystis aeruginosa exposed to 5,4'-dihydroxyflavone, down-regulation of iron/zinc ion transport and toxin synthesis was observed, indicating that iron(II)-related stimuli can reprogram transport and secondary metabolism. Such transcriptional and post-transcriptional changes help cells adjust uptake, storage, and efflux to maintain iron homeostasis.
Protein stability and post-translational responses
In simple terms: Iron(II) can change how long certain proteins last in the cell.
Iron(II) influences protein stability, as demonstrated by genetically encoded fluorescent reporters whose stability depends on labile iron levels. This post-translational layer allows rapid adaptation independent of transcription. Iron(II)-protein interactions can also be detected by clathrochelate-based sensors, highlighting direct molecular recognition events.
Redox chemistry and oxidative stress responses
In simple terms: Iron(II) can trigger oxidative chemistry that the cell must manage.
Iron(II) participates in redox reactions, including the oxidation of iron(II) to iron(III), which is exploited in carbon quantum dot-based fluorometric assays for nitrite. This redox activity means that iron(II) stimuli can induce oxidative stress responses, and cells must coordinate antioxidant defenses with iron handling. The balance between iron(II) availability and oxidative damage is a central feature of GO:0010040.
Cellular and physiological outcomes
In simple terms: The response ultimately changes how cells behave and function.
Downstream outcomes of iron(II) responses include changes in vascular endothelial structure and function after acute exposure, modulation of neutrophil extracellular trap formation relevant to cancer immunotherapy, and altered toxin synthesis in cyanobacteria. These physiological consequences illustrate the broad impact of GO:0010040 across cell types and organisms.
Key Genes Involved in GO:0010040 response to iron(II) ion
The following genes and proteins are representative of the cellular machinery and reporters used to study response to iron(II) ion, based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| Microcystis aeruginosa iron/zinc transport genes | Regulate iron and zinc ion transport in cyanobacteria | Down-regulated by 5,4'-dihydroxyflavone, linking iron(II) response to toxin synthesis |
| Microcystis aeruginosa toxin synthesis genes | Control toxin production | Co-regulated with iron/zinc transport under iron(II)-related stimuli |
| Iron(II) clathrochelate-binding proteins | Interact with iron(II) clathrochelates | Detected by induced circular dichroism for protein sensing |
| Vascular endothelial proteins | Maintain endothelial structure and function | Impaired by acute iron(II) exposure |
| Neutrophil extracellular trap (NET) components | Mediate NET formation | Regulated by iron to enhance cancer immunotherapy |
| Labile iron reporter proteins | Report intracellular labile iron via stability | Genetically encoded fluorescent reporter system |
| Iron(II)-1,10-phenanthroline complex targets | Form colored complexes with iron(II) | Used for sensitive iron determination by capillary electrophoresis |
| Nitrite assay proteins | Participate in iron(II) oxidation | Carbon quantum dot-based fluorometric nitrite assay |
| HER2 (ERBB2) | Cell surface receptor | Detected by aptamer-based impedimetric assay using iron(II) Prussian Blue analogues |
| MCF-7 cell proteins | Breast cancer cell markers | Living MCF-7 cells detected via iron(II) Prussian Blue analogues |
| Iron regulatory proteins (IRPs) | Post-transcriptional regulation of iron metabolism | General iron homeostasis machinery relevant to iron(II) responses |
| Ferritin | Iron storage protein | Central to buffering labile iron and oxidative stress |
| Transferrin receptor | Iron uptake | Modulates cellular iron(II) availability |
| Ferroportin | Iron export | Controls iron efflux and systemic iron balance |
| Hepcidin | Systemic iron regulator | Regulates iron absorption and recycling |
| NCOA4 | Ferritinophagy receptor | Links iron storage to labile iron release |
| FTH1 | Ferritin heavy chain | Ferroxidase activity, iron storage |
| FTL | Ferritin light chain | Iron storage and mineralization |
How Is response to iron(II) ion Regulated?
The response to iron(II) ion is regulated at multiple levels. Transcriptional control of iron transport and storage genes adjusts uptake and efflux in response to iron(II) stimuli. Post-transcriptional regulation via iron regulatory proteins and iron-responsive elements modulates the stability and translation of mRNAs encoding ferritin, transferrin receptor, and ferroportin. Post-translational mechanisms, including protein stability changes detected by genetically encoded reporters, provide rapid adaptation to labile iron fluctuations. In immune cells, iron-dependent regulation of neutrophil extracellular trap formation can be targeted to enhance cancer immunotherapy, indicating that iron(II) responses are integrated with immune signaling. Redox balance also regulates the response, as iron(II) oxidation and oxidative stress pathways influence cellular outcomes.
response to iron(II) ion and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| Vascular endothelial genes | Endothelial dysfunction from acute iron(II) exposure | Endothelial cell knockout of iron transport genes |
| Neutrophil extracellular trap components | Cancer immunotherapy resistance | Knockout of iron regulatory genes in neutrophils |
| Microcystis aeruginosa iron/zinc transporters | Cyanobacterial toxin production | Gene knockout or knockdown in cyanobacteria |
| HER2 (ERBB2) | Breast cancer detection | MCF-7 cell models with iron(II) Prussian Blue aptasensors |
| Labile iron reporter targets | Iron overload and oxidative stress | Knock-in of genetically encoded fluorescent reporters |
Vascular endothelial dysfunction and iron(II) overload
Acute exposure to iron(II) impairs vascular endothelial structure and function, suggesting that uncontrolled ferrous iron can damage the endothelium and contribute to vascular pathology. This links GO:0010040 to cardiovascular injury and highlights the need for models that test endothelial responses to iron(II).
Cancer immunotherapy and neutrophil extracellular traps
Inhibiting neutrophil extracellular trap formation through iron regulation enhances cancer immunotherapy, demonstrating that iron(II)-responsive pathways in immune cells can be therapeutically exploited. This connects GO:0010040 to immuno-oncology and suggests that iron-handling genes are candidate targets for combination therapies.
Microbial toxin production and environmental health
In Microcystis aeruginosa, exposure to 5,4'-dihydroxyflavone down-regulates iron/zinc ion transport and toxin synthesis, showing that iron(II)-related responses influence cyanobacterial toxin production with implications for water quality and public health.
Iron-related diagnostics and biosensing
Analytical advances such as iron(II)-1,10-phenanthroline capillary electrophoresis, carbon quantum dot fluorometric nitrite assays exploiting iron(II) oxidation, and gold nanoparticle-iron(II) Prussian Blue aptasensors for HER2 and MCF-7 cells support disease detection and monitoring related to iron(II) biology.
From response to iron(II) ion-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does a candidate gene mediate iron(II)-induced endothelial injury? | CRISPR knockout in endothelial cells |
| Does iron regulation of NET formation affect immunotherapy? | Knockout or point-mutation in neutrophil-like cells |
| How does iron(II) affect toxin synthesis in cyanobacteria? | Gene knockout in Microcystis aeruginosa |
| Can labile iron dynamics be visualized in live cells? | Knock-in of genetically encoded fluorescent reporter |
| Does a specific iron(II)-binding protein interact with clathrochelates? | Overexpression and purification for circular dichroism |
| Can iron(II) oxidation be harnessed for nitrite detection? | Overexpression of redox proteins in reporter assays |
How to Study the response to iron(II) ion Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Genetically encoded fluorescent reporter | Intracellular labile iron dynamics | Live-cell imaging of iron(II) responses |
| Iron(II) clathrochelate circular dichroism | Protein sensing and iron(II) interactions | Chemical biology of iron(II)-protein binding |
| Capillary electrophoresis with 1,10-phenanthroline | Iron(II) concentration | Sensitive iron determination |
| Carbon quantum dot fluorometric assay | Nitrite via iron(II) oxidation | Environmental and analytical detection |
| Gold nanoparticle-iron(II) Prussian Blue aptasensor | HER2 and living MCF-7 cells | Cancer cell detection |
| RNA sequencing | Transcriptional changes | Iron(II)-induced gene expression profiling |
| CRISPR knockout screening | Gene function in iron(II) response | Causal gene discovery |
| Proteomics | Protein abundance and stability | Iron(II)-dependent protein regulation |
Genetically encoded fluorescent reporters for labile iron
Genetically encoded fluorescent reporter systems based on protein stability enable tracking of intracellular labile iron with high spatiotemporal resolution. These reporters can be knocked into cell lines to monitor iron(II) dynamics in real time and to test how genetic perturbations alter labile iron pools.
Chemical probes and clathrochelate-based sensing
Iron(II) clathrochelates functionalized with carboxyalkylsulfide groups sense proteins via induced circular dichroism, providing a chemical biology approach to study iron(II)-protein interactions. Such probes complement genetic reporters and can be used in binding assays and screening workflows.
Analytical quantification of iron(II)
Capillary electrophoresis with iron(II)-1,10-phenanthroline complexes offers a sensitive way to determine iron. Carbon quantum dot-based fluorometric assays exploit the oxidation of iron(II) to iron(III) for nitrite detection. Gold nanoparticle conjugates with bimetallic manganese(II) and iron(II) Prussian Blue analogues enable aptamer-based impedimetric determination of HER2 and living MCF-7 cells.
Transcriptomics and functional genomics
RNA sequencing and functional genomics can reveal how iron(II) stimuli reprogram ion transport and toxin synthesis genes, as shown in Microcystis aeruginosa exposed to 5,4'-dihydroxyflavone. Combining transcriptomics with CRISPR screens helps identify causal genes in the response to iron(II) ion.
How CRISPR Can Be Used to Study GO:0010040 response to iron(II) ion
Knockout
CRISPR knockout of candidate iron transport or regulatory genes can test whether they are required for cellular responses to iron(II), such as endothelial injury or neutrophil extracellular trap formation. Knockout models in cyanobacteria can also reveal roles in toxin synthesis.
Point Mutation
Point mutations can dissect specific residues involved in iron(II) sensing, transport, or protein stability. For example, mutating iron-binding residues in reporter proteins can validate their role in labile iron detection.
Knock-in
Knock-in of genetically encoded fluorescent reporters allows precise tracking of labile iron in native genomic context, enabling real-time studies of iron(II) dynamics without overexpression artifacts.
Overexpression
Overexpression of iron(II)-binding proteins or clathrochelate targets can facilitate biochemical characterization, including circular dichroism-based protein sensing assays. Overexpression can also test gain-of-function effects in iron(II) response pathways.
How EDITGENE Supports response to iron(II) ion Research
Researchers studying response to iron(II) ion-related genes often need to determine whether a candidate gene is causally involved in iron sensing, transport, or downstream cellular outcomes. EDITGENE provides CRISPR-based cell models and screening services to accelerate this causal dissection across disease and environmental contexts.
Contact EDITGENE today to design your custom CRISPR model for response to iron(II) ion research.
Frequently Asked Questions About response to iron(II) ion
What is GO:0010040 response to iron(II) ion?
GO:0010040 is a biological process Gene Ontology term defined as any process that results in a change in state or activity of a cell or an organism as a result of an iron(II) ion stimulus.
What genes are involved in response to iron(II) ion?
Genes involved include iron/zinc transporters in Microcystis aeruginosa, vascular endothelial genes, neutrophil extracellular trap components, and iron homeostasis genes such as ferritin and transferrin receptor.
Why is iron(II) important for cells?
Iron(II) is the soluble, redox-active form of iron that supports essential chemistry but can cause oxidative damage if not properly buffered.
How do cells sense iron(II)?
Cells sense iron(II) through labile iron pools and specialized reporters; genetically encoded fluorescent reporters based on protein stability can track intracellular labile iron.
What diseases are linked to iron(II) responses?
Iron(II) responses are linked to vascular endothelial dysfunction, cancer immunotherapy resistance, and microbial toxin production.
How can I study response to iron(II) ion in the lab?
You can use genetically encoded fluorescent reporters, iron(II)-selective clathrochelates, capillary electrophoresis, and CRISPR knockout or knock-in models.
What methods detect iron(II) in cells?
Methods include genetically encoded fluorescent reporters, clathrochelate-based circular dichroism, capillary electrophoresis with 1,10-phenanthroline, and carbon quantum dot fluorometric assays.
Can CRISPR be used to study iron(II) response genes?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models allow causal testing of genes involved in iron(II) responses.
What is the role of iron(II) in cancer immunotherapy?
Inhibiting neutrophil extracellular trap formation through iron regulation can enhance cancer immunotherapy, linking iron(II) responses to immune cell function.
How does iron(II) affect cyanobacteria?
Exposure to 5,4'-dihydroxyflavone down-regulates iron/zinc ion transport and toxin synthesis in Microcystis aeruginosa, showing iron(II)-related environmental responses.
Conclusion
GO:0010040 response to iron(II) ion captures a fundamental biological process by which cells and organisms adapt to ferrous iron stimuli. From labile iron sensing and transcriptional reprogramming to redox chemistry and physiological outcomes, this term connects iron biology to vascular disease, cancer immunotherapy, and environmental toxin regulation. Advances in genetically encoded reporters, chemical probes, and CRISPR models continue to clarify the causal genes and mechanisms underlying this response. Understanding GO:0010040 will support the development of iron-targeted diagnostics and therapeutics across diverse biomedical fields.
References
- 1. Yu S et al.. 2023. Down-regulation of iron/zinc ion transport and toxin synthesis in Microcystis aeruginosa exposed to 5,4'-dihydroxyflavone.. J Hazard Mater 460:132396 PMID: 37672994
- 2. Losytskyy M et al.. 2020. Sensing of Proteins by ICD Response of Iron(II) Clathrochelates Functionalized by Carboxyalkylsulfide Groups.. Biomolecules 10(12) PMID: 33256144
- 3. Carnelli ARR et al.. 2025. Acute exposure to iron (II) impairs the vascular endothelial structure and function.. Biometals 38(4):1265-1280 PMID: 40526160
- 4. Ye J et al.. 2025. Inhibiting Neutrophil Extracellular Trap Formation through Iron Regulation for Enhanced Cancer Immunotherapy.. ACS Nano 19(9):9167-9181 PMID: 40011227
- 5. Xu J et al.. 1996. More sensitive way to determine iron using an iron(II)-1,10-phenanthroline complex and capillary electrophoresis.. J Chromatogr A 749(1-2):287-94 PMID: 8921599
- 6. Akyol A et al.. 2025. Tracking Intracellular Labile Iron with a Genetically Encoded Fluorescent Reporter System Based on Protein Stability.. ACS Sens 10(8):5854-5861 PMID: 40747620
- 7. Liu Y et al.. 2018. Carbon quantum dot-based fluorometric nitrite assay by exploiting the oxidation of iron(II) to iron(III).. Mikrochim Acta 185(2):129 PMID: 29594731
- 8. Zhou N et al.. 2019. Gold nanoparticles conjugated to bimetallic manganese(II) and iron(II) Prussian Blue analogues for aptamer-based impedimetric determination of the human epidermal growth factor receptor-2 and living MCF-7 cells.. Mikrochim Acta 186(2):75 PMID: 30627835
