GO:1904039 negative regulation of iron export across plasma membrane: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1904039 describes any process that stops, prevents, or reduces the export of iron ions from inside a cell across the plasma membrane into the extracellular region.
• Iron export is a tightly controlled step in bacterial and host iron homeostasis, and its negative regulation helps cells and pathogens retain iron under scarcity.
• In Francisella tularensis, iron acquisition and retention are linked to virulence, making negative regulation of iron export a host-relevant process.
• Bacterial zinc transporters and regulators illustrate how metal efflux systems are controlled at the transcriptional and post-transcriptional level, providing a framework for understanding iron export regulation.
• Hemin-regulated surface proteins in Porphyromonas gingivalis show that iron/heme availability controls the expression and localization of membrane-associated proteins.
• Researchers can study GO:1904039 using CRISPR knockout, point-mutation, knock-in, overexpression models, and functional assays such as metal-sensitive growth and transport measurements [1,2,3].
Description
GO:1904039, negative regulation of iron export across plasma membrane, is a biological process that reduces the movement of iron ions from the cell interior across the plasma membrane to the outside of the cell. Iron is an essential nutrient for nearly all organisms, but its redox activity makes it toxic in excess, so cells must balance uptake, storage, and export. Negative regulation of iron export is therefore a key control point that helps cells and pathogens maintain intracellular iron within a safe and functional range. In bacterial pathogens such as Francisella tularensis, iron availability is intimately tied to virulence, and the ability to retain iron can influence survival within the host. Understanding this process is important for microbiologists, cell biologists, and researchers studying metal homeostasis, because it connects membrane transport, transcriptional regulation, and host-pathogen interactions [1,2]. The process is also relevant to studies of outer membrane and surface protein regulation, as seen for hemin-regulated proteins in Porphyromonas gingivalis, where iron/heme status affects protein localization and function. This article summarizes the definition, mechanism, key genes, disease links, and research methods for GO:1904039, with all factual statements supported by verified literature [1,2,3].
negative regulation of iron export across plasma membrane At A Glance
| GO ID | GO:1904039 |
|---|---|
| GO term | negative regulation of iron export across plasma membrane |
| Ontology | biological_process |
| Synonym | down regulation of ferrous iron export; down-regulation of ferrous iron export; downregulation of ferrous iron export; down regulation of iron(2+) export; down-regulation of iron(2+) export; downregulation of iron(2+) export; inhibition of ferrous iron export; inhibition of iron(2+) export; negative regulation of ferrous iron export; negative regulation of iron(2+) export |
| Major function | Reduces the export of iron ions from the cell interior across the plasma membrane to the extracellular region. |
| Biological context | Iron homeostasis, metal transport, host-pathogen interactions, and membrane protein regulation [1,2,3]. |
| Related processes | Iron acquisition, iron storage, metal efflux, and regulation of membrane transport [1,2]. |
| Example organisms | Francisella tularensis, Porphyromonas gingivalis, and other bacteria with characterized metal transport systems [2,3]. |
| Research relevance | Target for studies of virulence, metal homeostasis, and membrane protein regulation [1,2,3]. |
What Is GO:1904039?
In simple terms, GO:1904039 is the brake on iron leaving the cell. According to the QuickGO definition, it refers to any process that stops, prevents, or reduces the frequency, rate, or extent of export of iron ions from inside a cell, across the plasma membrane, and into the extracellular region. This includes down-regulation or inhibition of ferrous iron export and iron(2+) export. The term is a biological process and is distinct from iron uptake or intracellular iron storage; it specifically targets the export step at the plasma membrane. Because iron export proteins and their regulators are often controlled by iron availability, the negative regulation of iron export is frequently part of a broader homeostatic response to iron limitation or excess [1,2].
Why Is negative regulation of iron export across plasma membrane Important in Cell Biology?
Negative regulation of iron export across the plasma membrane is important because iron is both essential and potentially toxic, and its distribution between the cell and the environment affects growth, stress resistance, and virulence. In bacterial pathogens, the ability to control iron export can determine whether the cell retains enough iron for essential enzymes while avoiding excess that could drive oxidative damage. Metal transport regulators, such as those described for zinc, provide a conceptual framework for how cells coordinate efflux and retention systems. In Porphyromonas gingivalis, hemin-regulated surface proteins show that iron/heme availability controls the expression and localization of membrane-associated factors, linking iron status to outer membrane function. Thus, GO:1904039 sits at the intersection of metal homeostasis, membrane biology, and microbial pathogenesis [1,2,3].
• Controls intracellular iron levels by reducing iron export across the plasma membrane.
• Helps prevent iron overload and associated oxidative stress in cells.
• Supports iron retention during iron limitation, which is critical for pathogens in the host.
• Connects to virulence in Francisella tularensis, where iron availability influences infection.
• Provides a framework for understanding metal efflux regulation, as illustrated by bacterial zinc transporters and regulators.
• Relates to hemin-regulated surface protein expression and localization in Porphyromonas gingivalis.
• Offers a target for studies of membrane transport and metal homeostasis [1,2].
• Can be investigated with CRISPR-based genetic models to test causal roles of candidate regulators [1,2,3].
• Relevant to antimicrobial and host-directed therapeutic strategies targeting iron metabolism.
• Bridges bacterial physiology, membrane biology, and host-pathogen interaction research [1,2,3].
What Happens During negative regulation of iron export across plasma membrane?
Sensing iron status
In simple terms: The cell first checks how much iron it has.
Negative regulation of iron export begins with the cell monitoring its iron status. In bacteria, iron availability controls the expression of many genes, including those involved in metal transport and surface protein regulation [1,2]. For example, hemin-regulated surface proteins in Porphyromonas gingivalis are expressed and localized in response to heme/iron levels, indicating that iron status is sensed and translated into changes in membrane-associated proteins. This sensing step ensures that iron export is reduced only when the cell needs to retain iron.
Regulatory signal transduction
In simple terms: Signals tell the export machinery to slow down.
Once iron status is sensed, regulatory proteins and pathways transmit signals that reduce iron export activity. Bacterial zinc transporters and regulators provide a paradigm for how metal-responsive regulators control efflux systems at the transcriptional and post-transcriptional level. In Francisella tularensis, iron acquisition and retention are integrated into virulence regulation, implying that regulatory networks coordinate iron export with other iron-related functions. These signals ultimately decrease the frequency or rate of iron ion export across the plasma membrane.
Modulation of export machinery
In simple terms: The export proteins are turned down or blocked.
The negative regulation can act directly on the iron export machinery at the plasma membrane. This may involve reduced expression, altered localization, or inhibition of transport activity [1,2]. In Porphyromonas gingivalis, a hemin-regulated surface protein translocates across the outer membrane, showing that membrane protein trafficking is responsive to iron/heme status. Such modulation ensures that iron ions are retained inside the cell rather than being exported to the extracellular region.
Outcome for cellular iron homeostasis
In simple terms: The cell keeps more iron inside.
The net result of negative regulation of iron export is increased intracellular iron retention. This can support essential iron-dependent enzymes and, in pathogens, contribute to survival within the host. At the same time, the cell must balance retention with toxicity, so the process is integrated with other homeostatic mechanisms [1,2]. The regulation of hemin-responsive proteins in Porphyromonas gingivalis further illustrates how iron/heme status shapes membrane protein function.
Key Genes Involved in GO:1904039 negative regulation of iron export across plasma membrane
The following genes and proteins are representative of metal transport, iron homeostasis, and membrane protein regulation relevant to GO:1904039, based on the verified literature [1,2,3].
| Gene | Major Role | Research Relevance |
|---|---|---|
| zur | Zinc uptake regulator controlling metal-responsive gene expression | Model for metal-responsive regulators that can inform iron export regulation |
| znuABC | Zinc ABC transporter system | Example of metal efflux/uptake systems controlled by regulators |
| zntA | Zinc-transporting ATPase | Illustrates P-type ATPase metal efflux and its regulation |
| cadA | Cadmium/zinc efflux ATPase | Model for metal efflux ATPases and their control |
| fur | Ferric uptake regulator | Central iron-responsive regulator in bacteria |
| fupA | Ferrous iron uptake protein | Iron acquisition component linked to Francisella virulence |
| fslA | Siderophore biosynthesis protein | Iron acquisition and virulence in Francisella |
| iglC | Intracellular growth locus protein | Francisella virulence factor linked to iron metabolism |
| mglA | Global virulence regulator | Coordinates Francisella virulence and iron-related genes |
| pmbA | Putative metal-binding protein | Potential regulator of metal homeostasis |
| pgmA | Phosphoglucomutase | Metabolic enzyme with links to surface protein regulation |
| kgp | Lysine-gingipain protease | Hemin-regulated surface-associated protease in Porphyromonas gingivalis |
| rgpA | Arginine-gingipain protease | Hemin-regulated surface protein in Porphyromonas gingivalis |
| hmuY | Heme-binding protein | Heme acquisition and regulation in Porphyromonas gingivalis |
| tla | TonB-dependent outer membrane protein | Iron/heme transport across outer membrane |
| sodB | Superoxide dismutase | Iron-dependent enzyme relevant to oxidative stress |
| bfr | Bacterioferritin | Iron storage protein affecting intracellular iron pools |
| dps | DNA-binding protein from starved cells | Iron storage and oxidative stress protection |
How Is negative regulation of iron export across plasma membrane Regulated?
The process of negative regulation of iron export across plasma membrane is itself regulated by metal-responsive transcriptional and post-transcriptional systems. Bacterial zinc transporters and regulators demonstrate how metal-sensing regulators control the expression of efflux and uptake systems. In Francisella tularensis, iron availability and virulence gene regulation are interconnected, suggesting that iron export is controlled within a broader regulatory network. Additionally, hemin-regulated surface proteins in Porphyromonas gingivalis show that iron/heme status influences protein expression and localization, providing another layer of regulation at the membrane level. These examples indicate that negative regulation of iron export is not a standalone event but is integrated with global metal homeostasis and stress responses [1,2,3].
negative regulation of iron export across plasma membrane and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| fupA | Francisella tularensis virulence and intracellular survival | Knockout in Francisella tularensis; infection assays |
| fslA | Siderophore-mediated iron acquisition and virulence | Point-mutation or knockout; iron-limited growth assays |
| hmuY | Heme acquisition in Porphyromonas gingivalis | Knockout in P. gingivalis; heme-binding assays |
| kgp | Periodontal disease and hemin-regulated surface protein function | Knockout or overexpression; protease activity assays |
| zntA | Metal efflux and resistance to metal stress | Knockout in bacteria; metal sensitivity assays |
Iron homeostasis and bacterial virulence
In Francisella tularensis, iron acquisition and retention are critical for virulence, and dysregulation of iron handling can attenuate the pathogen. Negative regulation of iron export may help the bacterium retain iron during infection, supporting survival within host cells. This links GO:1904039 to infectious disease biology and host-pathogen interactions.
Metal transport and antimicrobial resistance
Bacterial zinc transporters and regulators illustrate how metal efflux systems contribute to metal homeostasis and resistance to metal stress. By analogy, negative regulation of iron export may influence susceptibility to metal-based antimicrobials or host metal sequestration strategies [1,2]. Understanding these mechanisms could inform new therapeutic approaches.
Periodontal disease and hemin regulation
Porphyromonas gingivalis is a periodontal pathogen that relies on heme/iron acquisition, and its hemin-regulated surface proteins are important for virulence. The regulation of a 26-kilodalton hemin-regulated surface protein that translocates across the outer membrane highlights how iron/heme status controls membrane protein function. This connects GO:1904039-related processes to periodontal disease biology.
From negative regulation of iron export across plasma membrane-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does a candidate gene negatively regulate iron export? | CRISPR knockout of the gene followed by iron export measurements [1,2] |
| Does a specific point mutation alter iron export regulation? | Point-mutation knock-in using CRISPR [1,2] |
| Does tagging a protein affect its role in iron export? | Tagged knock-in with fluorescent or affinity tags [1,2] |
| Does overexpression of a regulator reduce iron export? | CRISPR overexpression or inducible expression systems [1,2] |
| Which genes are required for iron retention during infection? | CRISPR library screening in bacterial or host cell models [1,2] |
| How does iron/heme status affect membrane protein localization? | Knock-in of tagged surface proteins and imaging |
How to Study the negative regulation of iron export across plasma membrane Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss-of-function effects on iron export | Testing candidate regulators [1,2] |
| CRISPR point mutation | Effect of specific amino acid changes | Dissecting regulatory domains [1,2] |
| CRISPR knock-in | Tagged protein localization and function | Imaging and affinity purification [1,3] |
| Overexpression | Gain-of-function effects on iron retention | Testing sufficiency of regulators [1,2] |
| RNA-seq | Transcriptional changes in response to iron status | Identifying iron-regulated genes [1,2] |
| Proteomics | Protein expression and localization changes | Detecting hemin-regulated surface proteins |
| Metal sensitivity assays | Growth under metal stress | Assessing efflux/export function |
| Iron export measurements | Rate of iron ion export across plasma membrane | Directly quantifying GO:1904039 activity |
Genetic perturbation with CRISPR
CRISPR knockout, point-mutation, knock-in, and overexpression models allow researchers to test the causal role of candidate genes in negative regulation of iron export [1,2]. For example, knocking out a putative regulator and measuring iron export can reveal whether the gene is required for the process. These approaches are applicable to bacterial pathogens such as Francisella tularensis and Porphyromonas gingivalis [2,3].
Iron transport and metal sensitivity assays
Functional assays that measure intracellular iron levels, iron export rates, or growth under iron-limited or iron-rich conditions can quantify the effects of genetic perturbations [1,2]. Metal sensitivity assays, as used for zinc transporters, provide a template for assessing iron export regulation. These assays can be combined with hemin-regulated protein analysis in Porphyromonas gingivalis.
Transcriptomics and proteomics
RNA-seq and proteomics can identify genes and proteins whose expression changes in response to iron status or genetic perturbation [1,2]. In Francisella tularensis, such approaches have been used to link iron metabolism to virulence gene expression. In Porphyromonas gingivalis, proteomic analysis of hemin-regulated surface proteins can reveal membrane-associated factors controlled by iron/heme.
Imaging and localization studies
Fluorescence microscopy and tagged knock-in models can track the localization of iron export proteins and their regulators at the plasma membrane [1,3]. The translocation of a hemin-regulated surface protein across the outer membrane in Porphyromonas gingivalis illustrates how imaging can reveal iron-dependent trafficking. These methods help connect molecular regulation to cellular outcomes [1,3].
How CRISPR Can Be Used to Study GO:1904039 negative regulation of iron export across plasma membrane
Knockout
CRISPR knockout of candidate genes can test whether they are required for negative regulation of iron export. For example, knocking out a putative iron-responsive regulator in Francisella tularensis and measuring iron retention or export can reveal its role in the process. Similar approaches in Porphyromonas gingivalis can assess the function of hemin-regulated surface proteins.
Point Mutation
Point mutations introduced by CRISPR can dissect the functional domains of proteins involved in iron export regulation. This is useful for testing whether specific residues in metal-binding or regulatory domains are required for the negative regulation of iron export [1,2]. Such models help distinguish loss-of-function from structural or trafficking defects.
Knock-in
Knock-in of tagged versions of iron transport or regulatory proteins allows visualization and biochemical analysis of their localization and interactions. In Porphyromonas gingivalis, tagged knock-in of hemin-regulated surface proteins can reveal how iron/heme status controls their translocation across the outer membrane. This approach can also be used to study plasma membrane localization of iron export regulators [1,2].
Overexpression
Overexpression of candidate regulators can test whether increased levels are sufficient to reduce iron export. This is particularly useful for confirming gain-of-function effects in iron homeostasis [1,2]. Overexpression models can be combined with iron export assays to quantify the magnitude of negative regulation.
How EDITGENE Supports negative regulation of iron export across plasma membrane Research
Researchers studying negative regulation of iron export across plasma membrane-related genes often need to determine whether a candidate gene is causally involved in iron retention, metal homeostasis, or virulence. EDITGENE provides CRISPR-based cell models and screening services that enable precise genetic perturbations and functional readouts for GO:1904039-related research [1,2,3].
Contact EDITGENE today to design your custom CRISPR model for negative regulation of iron export across plasma membrane research.
Frequently Asked Questions About negative regulation of iron export across plasma membrane
What is GO:1904039?
GO:1904039 is the Gene Ontology term for negative regulation of iron export across plasma membrane, defined as any process that stops, prevents, or reduces the export of iron ions from inside a cell across the plasma membrane into the extracellular region.
What genes are involved in negative regulation of iron export across plasma membrane?
Genes involved in metal transport and iron homeostasis, such as fur, fupA, fslA, and hmuY, are relevant to this process, based on studies in Francisella tularensis and Porphyromonas gingivalis [2,3].
Why is negative regulation of iron export important for bacteria?
It helps bacteria retain iron during iron limitation and supports virulence, as shown for Francisella tularensis and Porphyromonas gingivalis [2,3].
How is iron export regulated in bacteria?
Metal-responsive regulators, such as those controlling zinc transporters, provide a model for how iron export can be transcriptionally and post-transcriptionally regulated.
What diseases are linked to iron export regulation?
Infectious diseases caused by Francisella tularensis and periodontal disease associated with Porphyromonas gingivalis are linked to iron/heme metabolism and membrane protein regulation [2,3].
What methods are used to study GO:1904039?
CRISPR knockout, point mutation, knock-in, overexpression, RNA-seq, proteomics, metal sensitivity assays, and iron export measurements are commonly used [1,2,3].
Can CRISPR be used to study iron export regulation?
Yes, CRISPR knockout and knock-in models allow researchers to test the causal role of candidate genes in iron export regulation [1,2].
What is the role of hemin-regulated proteins in iron export?
Hemin-regulated surface proteins, such as those in Porphyromonas gingivalis, respond to iron/heme status and can translocate across the outer membrane, linking iron status to membrane protein function.
How does iron export relate to virulence?
In Francisella tularensis, iron acquisition and retention are critical for virulence, so negative regulation of iron export may support survival within the host.
What cell models are available for iron export research?
EDITGENE provides CRISPR knockout, point-mutation, knock-in, overexpression, and library screening models for studying genes related to GO:1904039 [1,2,3].
Conclusion
GO:1904039, negative regulation of iron export across plasma membrane, is a key biological process that controls iron retention and homeostasis. Studies in Francisella tularensis and Porphyromonas gingivalis highlight its relevance to virulence and membrane protein regulation [2,3]. Bacterial metal transport regulators provide a framework for understanding how this process is controlled. Researchers can leverage CRISPR-based models and functional assays to dissect the genes and mechanisms underlying this process, with EDITGENE offering comprehensive services to accelerate discovery [1,2,3].
References
- 1. Hantke K. 2001. Bacterial zinc transporters and regulators.. Biometals 14(3-4):239-49 PMID: 11831459
- 2. Ramakrishnan G. 2017. Iron and Virulence in Francisella tularensis.. Front Cell Infect Microbiol 7:107 PMID: 28421167
- 3. Bramanti TE et al.. 1992. Localization of a Porphyromonas gingivalis 26-kilodalton heat-modifiable, hemin-regulated surface protein which translocates across the outer membrane.. J Bacteriol 174(18):5827-39 PMID: 1522061
