GO:0071614 linoleic acid epoxygenase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0071614 (linoleic acid epoxygenase activity) is a molecular function defined as the NADPH- and oxygen-dependent conversion of linoleic acid to a cis-epoxyoctadecenoic acid.
• CYP2C9 was identified as a principal human liver microsomal linoleic acid epoxygenase, establishing a direct enzyme-function link for this GO term.
• Endothelial cells display basal and inducible anti-inflammatory epoxygenase activity, showing that this function operates in vascular biology beyond xenobiotic metabolism.
• CYP450-derived oxylipins, including linoleic acid epoxides and their diol products, mediate inflammatory resolution.
• The linoleic acid-derived diol 12,13-DiHOME enhances NLRP3 inflammasome activation in macrophages, connecting this activity to innate immune signaling.
• Linoleic acid derivatives are implicated in pathological pregnancies and human reproduction, indicating clinical relevance for reproductive research.
Description
GO:0071614, linoleic acid epoxygenase activity, is a molecular function in the Gene Ontology that describes the catalysis of an NADPH- and oxygen-dependent reaction converting linoleic acid to a cis-epoxyoctadecenoic acid. This activity sits at the interface of lipid biochemistry and cell signaling, because the epoxide products and their downstream diols are bioactive oxylipins rather than inert metabolic intermediates. For researchers, the term provides a precise annotation target when assigning function to cytochrome P450 enzymes and when interpreting lipidomic datasets that report epoxyoctadecenoic acids. The function is experimentally anchored in human liver microsomes, where CYP2C9 was identified as a linoleic acid epoxygenase, and in endothelial cells, where basal and inducible anti-inflammatory epoxygenase activity has been demonstrated. Beyond these cell types, cytochrome P450 enzymes catalyze bisallylic hydroxylation and epoxidation of polyunsaturated fatty acids, a broader catalytic theme that includes linoleic acid epoxidation. The products of this activity participate in inflammatory resolution programs mediated by CYP450-derived oxylipins, and one specific linoleic acid-derived diol, 12,13-DiHOME, enhances NLRP3 inflammasome activation in macrophages. Because the same enzymatic activity can yield products with opposing or context-dependent biological effects, GO:0071614 is useful for separating catalytic function from downstream phenotype. It also appears in reproductive and pregnancy-related literature, where arachidonic and linoleic acid derivatives are discussed in relation to pathological pregnancies and the human reproduction process. Plant epoxygenases with fatty acid specificity have also been characterized, showing that the chemistry of linoleic acid epoxidation is not restricted to mammals.
linoleic acid epoxygenase activity At A Glance
| GO ID | GO:0071614 |
|---|---|
| GO term | linoleic acid epoxygenase activity |
| Ontology | molecular_function |
| Synonym | linoleic acid monooxygenase activity |
| Major function | Catalysis of an NADPH- and oxygen-dependent reaction that converts linoleic acid to a cis-epoxyoctadecenoic acid |
| Representative enzyme | CYP2C9 has been identified as a human liver microsomal linoleic acid epoxygenase |
| Cellular context | Basal and inducible epoxygenase activity has been demonstrated in endothelial cells |
| Product class | cis-epoxyoctadecenoic acids and downstream diols such as 12,13-DiHOME |
| Related biology | CYP450-derived oxylipins mediate inflammatory resolution |
What Is GO:0071614?
In practical terms, GO:0071614 describes an enzyme activity that uses NADPH and molecular oxygen to insert an oxygen atom into linoleic acid, forming a cis-epoxyoctadecenoic acid. The QuickGO definition specifies an NADPH- and oxygen-dependent reaction that converts linoleic acid to a cis-epoxyoctadecenoic acid, and the synonym linoleic acid monooxygenase activity reflects the monooxygenase chemistry involved. This is a molecular_function annotation, so it should be applied to the enzyme performing the chemistry rather than to a pathway, a cell type, or a disease state.
Why Is linoleic acid epoxygenase activity Important in Cell Biology?
GO:0071614 matters because it assigns a precise catalytic function to enzymes that generate bioactive lipid mediators from linoleic acid, a abundant dietary and endogenous fatty acid. The epoxide products and their diol derivatives are not merely metabolic waste; they participate in inflammatory resolution and can enhance innate immune activation through the NLRP3 inflammasome. Endothelial epoxygenase activity further links this function to vascular anti-inflammatory programs. In reproductive biology, linoleic and arachidonic acid derivatives have been discussed in the context of pathological pregnancies and human reproduction. For annotation and drug-discovery teams, the term provides a clean functional readout that can be separated from broader cytochrome P450 activities.
• Provides a defined molecular_function annotation for enzymes converting linoleic acid to cis-epoxyoctadecenoic acids.
• Links cytochrome P450 biochemistry to bioactive oxylipin production.
• Supports interpretation of endothelial anti-inflammatory epoxygenase activity.
• Connects lipid epoxidation to innate immune signaling via 12,13-DiHOME and NLRP3.
• Relevant to reproductive and pregnancy-related lipid mediator research.
• Helps distinguish epoxygenase chemistry from bisallylic hydroxylation of polyunsaturated fatty acids.
• Offers a comparative framework with plant fatty acid epoxygenases.
• Useful for lipidomics annotation of epoxyoctadecenoic acid species.
• Guides functional assignment of CYP2C9 and related cytochrome P450 enzymes.
• Supports mechanistic studies of inflammatory resolution programs.
Molecular Mechanism of linoleic acid epoxygenase activity
Substrate recognition and binding of linoleic acid
In simple terms: The enzyme first picks up linoleic acid and holds it in its active site.
Linoleic acid epoxygenase activity requires binding of linoleic acid as the substrate before catalysis can occur. Cytochrome P450 enzymes that catalyze bisallylic hydroxylation and epoxidation of polyunsaturated fatty acids provide the structural and mechanistic context for this substrate interaction. In human liver microsomes, CYP2C9 was identified as a linoleic acid epoxygenase, demonstrating that a specific cytochrome P450 can recognize linoleic acid and support its conversion. The same catalytic theme appears in endothelial cells, where basal and inducible epoxygenase activity indicates that substrate access and enzyme availability are regulated in a cell-type-specific manner.
NADPH- and oxygen-dependent epoxidation chemistry
In simple terms: Using NADPH and oxygen, the enzyme inserts one oxygen atom into linoleic acid to make an epoxide.
The GO definition specifies an NADPH- and oxygen-dependent reaction that converts linoleic acid to a cis-epoxyoctadecenoic acid. This monooxygenase chemistry is consistent with the synonym linoleic acid monooxygenase activity, in which one atom of molecular oxygen is incorporated into the substrate. The reaction produces a cis-epoxyoctadecenoic acid, a product class that can be measured in lipidomic workflows and linked to downstream oxylipin biology. Because the chemistry depends on NADPH and oxygen, experimental systems must preserve reducing equivalents and oxygen availability to observe activity.
Product formation and downstream oxylipin signaling
In simple terms: The epoxide product can be further converted into signaling molecules that affect inflammation and immunity.
CYP450-derived oxylipins mediate inflammatory resolution, placing the products of linoleic acid epoxygenase activity within a broader signaling network. One linoleic acid-derived diol, 12,13-DiHOME, enhances NLRP3 inflammasome activation in macrophages, showing that downstream metabolites of this activity can amplify innate immune responses. Endothelial cells exhibit basal and inducible anti-inflammatory epoxygenase activity, indicating that product formation can be associated with anti-inflammatory programs in the vasculature. These findings illustrate that the biological outcome of GO:0071614 depends on the cell type and the metabolic fate of the epoxide product.
Enzyme specificity and comparative context
In simple terms: Different enzymes can perform similar chemistry, so specificity matters when assigning the GO term.
CYP2C9 was identified as a human liver microsomal linoleic acid epoxygenase, providing a concrete enzyme-function assignment for this activity. Cytochrome P450 enzymes can also catalyze bisallylic hydroxylation and epoxidation of polyunsaturated fatty acids, so assays should distinguish epoxidation from competing reactions. In plants, a fatty acid epoxygenase from broad bean has been characterized with respect to specificity, showing that linoleic acid epoxidation chemistry is evolutionarily widespread. This comparative context helps researchers avoid over-assigning GO:0071614 to enzymes that primarily perform other reactions.
Regulation of epoxygenase activity in cells
In simple terms: Cells can turn this activity up or down depending on context.
Endothelial cells display both basal and inducible anti-inflammatory epoxygenase activity, indicating that the function is not constitutive at a fixed level but can be modulated. CYP450-derived oxylipins mediate inflammatory resolution, which implies that the activity is embedded in regulated inflammatory pathways. In reproductive biology, arachidonic and linoleic acid derivatives have been discussed in relation to pathological pregnancies and the human reproduction process, suggesting hormonal or pregnancy-associated modulation of lipid mediator production. These observations support the view that GO:0071614 is a regulated molecular function rather than a static housekeeping activity.
Key Genes Involved in GO:0071614 linoleic acid epoxygenase activity
The following genes and proteins are directly or contextually linked to linoleic acid epoxygenase activity (GO:0071614) in the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CYP2C9 | Identified as a human liver microsomal linoleic acid epoxygenase | Direct enzyme-function anchor for GO:0071614 |
| CYP450 family members | Catalyze bisallylic hydroxylation and epoxidation of polyunsaturated fatty acids | Mechanistic context for linoleic acid epoxidation |
| Endothelial epoxygenase enzymes | Mediate basal and inducible anti-inflammatory epoxygenase activity | Vascular biology model for this activity |
| CYP450-derived oxylipin pathway enzymes | Produce oxylipins that mediate inflammatory resolution | Links activity to resolution programs |
| 12,13-DiHOME-producing pathway | Generates a linoleic acid-derived diol that enhances NLRP3 inflammasome activation | Connects activity to innate immunity |
| NLRP3 | Inflammasome sensor enhanced by 12,13-DiHOME | Downstream readout of linoleic acid derivative signaling |
| Arachidonic acid derivative pathway | Produces related lipid mediators in reproduction | Comparative lipid mediator biology |
| Linoleic acid derivative pathway | Produces lipid mediators relevant to pregnancy | Reproductive pathology context |
| Broad bean fatty acid epoxygenase | Plant enzyme with fatty acid epoxygenase specificity | Comparative enzymology |
| G protein signaling components | Modulated by arachidonic acid in Leydig cell membranes | Related fatty acid signaling context |
| Leydig cell membrane proteins | GTPase activity modulated by arachidonic acid | Endocrine and reproductive context |
| Macrophage lipid-sensing machinery | Responds to 12,13-DiHOME | Innate immune model |
| Endothelial inflammatory signaling machinery | Responds to epoxygenase products | Vascular inflammation model |
| Inflammatory resolution mediators | Downstream of CYP450-derived oxylipins | Resolution pharmacology |
| Polyunsaturated fatty acid substrates | Include linoleic acid as substrate | Substrate definition for the activity |
| cis-epoxyoctadecenoic acid products | Direct products of the activity | Lipidomic readout |
How Is linoleic acid epoxygenase activity Regulated?
Linoleic acid epoxygenase activity is regulated at the level of enzyme availability and cellular context. Endothelial cells show basal and inducible anti-inflammatory epoxygenase activity, indicating that the function can be upregulated in response to stimuli. CYP450-derived oxylipins mediate inflammatory resolution, which places the activity within regulated inflammatory circuits. In reproductive biology, arachidonic and linoleic acid derivatives have been discussed in relation to pathological pregnancies and the human reproduction process, suggesting that physiological state influences lipid mediator production. Arachidonic acid can modulate GTPase activity of G proteins in rat Leydig cell membranes, illustrating that fatty acid signaling can intersect with membrane signaling systems. Together, these observations indicate that GO:0071614 is not a fixed housekeeping function but is subject to cell-type and context-dependent control.
linoleic acid epoxygenase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CYP2C9 | Linoleic acid epoxygenase activity in liver microsomes | Hepatocyte or liver microsome model with CYP2C9 knockout |
| NLRP3 | Inflammasome activation enhanced by 12,13-DiHOME | Macrophage model with NLRP3 knockout or point mutation |
| Endothelial epoxygenase enzymes | Anti-inflammatory epoxygenase activity in endothelium | Endothelial cell model with inducible overexpression |
| CYP450 oxylipin pathway | Inflammatory resolution | Macrophage or endothelial model with pathway perturbation |
| Linoleic acid derivative pathway | Pathological pregnancies and reproduction | Reproductive cell model with lipid mediator profiling |
Inflammatory and innate immune disease
The linoleic acid-derived diol 12,13-DiHOME enhances NLRP3 inflammasome activation in macrophages, linking products of linoleic acid epoxygenase activity to innate immune amplification. CYP450-derived oxylipins mediate inflammatory resolution, so dysregulation of this activity could shift the balance between resolution and persistent inflammation. Endothelial cells display basal and inducible anti-inflammatory epoxygenase activity, suggesting that vascular inflammatory states may involve altered epoxygenase function. These findings position GO:0071614 within inflammatory disease biology, although the precise disease associations require further study.
Reproductive and pregnancy-related pathology
Arachidonic and linoleic acid derivatives have been discussed in relation to pathological pregnancies and the human reproduction process. Because linoleic acid epoxygenase activity generates cis-epoxyoctadecenoic acids that can be further metabolized to bioactive diols, altered activity could influence lipid mediator profiles in reproductive tissues. Arachidonic acid modulation of G protein GTPase activity in rat Leydig cell membranes further indicates that fatty acid signaling intersects with endocrine cell membranes. These observations support research into GO:0071614 in reproductive pathology, while the mechanistic links remain to be fully defined.
Vascular and endothelial dysfunction
Endothelial cells exhibit basal and inducible anti-inflammatory epoxygenase activity, connecting linoleic acid epoxygenase function to vascular homeostasis. CYP450-derived oxylipins mediate inflammatory resolution, a process that is often impaired in vascular disease. Because the products of GO:0071614 can be either anti-inflammatory or immune-activating depending on context, endothelial models are useful for dissecting how this activity contributes to vascular phenotypes.
From linoleic acid epoxygenase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is CYP2C9 required for linoleic acid epoxygenase activity in liver cells? | CYP2C9 knockout hepatocyte or liver microsome model |
| Does loss of epoxygenase activity alter endothelial anti-inflammatory responses? | Endothelial cell knockout of candidate epoxygenase |
| Does 12,13-DiHOME production require a specific epoxygenase? | Macrophage knockout or point-mutation model with lipidomics |
| Can epoxygenase activity be enhanced to promote inflammatory resolution? | Overexpression of candidate epoxygenase in macrophages or endothelial cells |
| What is the role of epoxygenase products in reproductive pathology? | Reproductive cell model with knock-in reporter or overexpression |
| How does a disease-associated variant affect catalytic activity? | Point-mutation knock-in of the variant in a cell model |
How to Study the linoleic acid epoxygenase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Targeted lipidomics | cis-epoxyoctadecenoic acids and downstream diols | Quantify products of GO:0071614 |
| NADPH-dependent enzyme assay | Catalytic conversion of linoleic acid | Biochemical validation of epoxygenase activity |
| Oxygen-controlled incubation | Oxygen dependence of the reaction | Confirm monooxygenase mechanism |
| CYP2C9 knockout | Requirement of CYP2C9 for activity | Assign enzyme-function relationship |
| Endothelial cell activity assay | Basal and inducible epoxygenase activity | Vascular anti-inflammatory studies |
| Macrophage NLRP3 readout | Inflammasome activation by 12,13-DiHOME | Innate immune mechanism studies |
| Oxylipin profiling | CYP450-derived mediators | Inflammatory resolution research |
| Reproductive cell lipid profiling | Linoleic and arachidonic acid derivatives | Pregnancy and reproduction studies |
Lipidomic detection of cis-epoxyoctadecenoic acids
Because GO:0071614 produces cis-epoxyoctadecenoic acids from linoleic acid, targeted lipidomics is a direct way to measure activity. Researchers can quantify epoxide products and their downstream diols, such as 12,13-DiHOME, to connect enzyme function to product formation. CYP450-derived oxylipins can also be profiled to place the activity within inflammatory resolution networks. These measurements are most informative when paired with genetic perturbation of the candidate epoxygenase.
Enzyme activity assays with NADPH and oxygen control
The definition of GO:0071614 specifies NADPH- and oxygen-dependent catalysis, so biochemical assays should control both cofactor and oxygen availability. Human liver microsomal systems were used to identify CYP2C9 as a linoleic acid epoxygenase, providing a template for activity assays. Endothelial cell systems can be used to measure basal and inducible epoxygenase activity in a cellular context. Comparative assays with plant fatty acid epoxygenases can help define substrate specificity and reaction selectivity.
Genetic perturbation and functional readouts
Knockout, point-mutation, and overexpression models allow researchers to test whether a candidate gene is necessary or sufficient for linoleic acid epoxygenase activity. Macrophage models are particularly useful for linking epoxygenase products to NLRP3 inflammasome activation. Endothelial models can reveal whether the activity contributes to anti-inflammatory programs. Combining genetic perturbation with lipidomics and inflammatory readouts provides a causal chain from enzyme to product to phenotype.
Reproductive and endocrine model systems
Because linoleic and arachidonic acid derivatives have been discussed in pathological pregnancies and human reproduction, reproductive cell models can be used to study this activity in a relevant physiological context. Rat Leydig cell membranes have been used to study arachidonic acid modulation of G protein GTPase activity, illustrating endocrine membrane signaling approaches. These models can be combined with lipid mediator profiling to test whether epoxygenase products influence reproductive cell function.
How CRISPR Can Be Used to Study GO:0071614 linoleic acid epoxygenase activity
Knockout
CRISPR knockout of candidate epoxygenase genes, such as CYP2C9, can test whether the enzyme is required for linoleic acid epoxygenase activity in a given cell type. Knockout of downstream signaling components, such as NLRP3, can separate product formation from inflammasome activation. Endothelial knockout models can reveal whether basal and inducible anti-inflammatory epoxygenase activity depends on a specific enzyme. These models are most powerful when combined with lipidomic measurement of cis-epoxyoctadecenoic acids.
Point Mutation
Point-mutation models can test whether specific residues are required for NADPH- and oxygen-dependent catalysis of linoleic acid. Disease-associated or functionally interesting variants can be introduced into the endogenous locus to assess effects on epoxide product formation. Point mutations in downstream signaling proteins, such as NLRP3, can be used to dissect how 12,13-DiHOME enhances inflammasome activation. These experiments help distinguish catalytic function from scaffolding or regulatory roles.
Knock-in
Knock-in of tagged or reporter alleles can enable tracking of epoxygenase expression and localization in endothelial or liver cells. Knock-in of a candidate variant can test its effect on linoleic acid epoxygenase activity in a physiological context. Reporter knock-in models can also be used to monitor inducible epoxygenase activity in inflammatory settings. These approaches support precise functional annotation of GO:0071614 in relevant cell types.
Overexpression
Overexpression of a candidate epoxygenase can test whether increased enzyme levels are sufficient to raise cis-epoxyoctadecenoic acid production. In endothelial cells, overexpression can be used to enhance anti-inflammatory epoxygenase activity and assess downstream effects. In macrophages, overexpression of the pathway that generates 12,13-DiHOME can be used to study NLRP3 inflammasome activation. Overexpression models are useful for linking increased activity to inflammatory resolution or immune activation phenotypes.
How EDITGENE Supports linoleic acid epoxygenase activity Research
Researchers studying linoleic acid epoxygenase activity-related genes often need to determine whether a candidate gene is causally involved in linoleic acid epoxidation, whether a specific variant alters catalytic function, or whether increased enzyme levels are sufficient to change oxylipin production. EDITGENE provides CRISPR-based cell model services that allow these questions to be tested with defined genetic perturbations and functional readouts.
Contact EDITGENE today to design your custom CRISPR model for linoleic acid epoxygenase activity research.
Frequently Asked Questions About linoleic acid epoxygenase activity
What is linoleic acid epoxygenase activity?
It is a molecular function defined as the NADPH- and oxygen-dependent conversion of linoleic acid to a cis-epoxyoctadecenoic acid, annotated as GO:0071614.
What is the GO ID for linoleic acid epoxygenase activity?
The GO ID is GO:0071614, with the synonym linoleic acid monooxygenase activity.
What genes are involved in linoleic acid epoxygenase activity?
CYP2C9 has been identified as a human liver microsomal linoleic acid epoxygenase, and broader cytochrome P450 enzymes catalyze related polyunsaturated fatty acid epoxidation.
Which enzyme was identified as a human liver microsomal linoleic acid epoxygenase?
CYP2C9 was identified as a human liver microsomal linoleic acid epoxygenase.
Is linoleic acid epoxygenase activity NADPH-dependent?
Yes, the GO definition specifies an NADPH- and oxygen-dependent reaction that converts linoleic acid to a cis-epoxyoctadecenoic acid.
What products are formed by linoleic acid epoxygenase activity?
The reaction produces cis-epoxyoctadecenoic acids, which can be further metabolized to bioactive diols such as 12,13-DiHOME.
How is linoleic acid epoxygenase activity related to inflammation?
CYP450-derived oxylipins mediate inflammatory resolution, and the linoleic acid-derived diol 12,13-DiHOME enhances NLRP3 inflammasome activation in macrophages.
Do endothelial cells have linoleic acid epoxygenase activity?
Endothelial cells display basal and inducible anti-inflammatory epoxygenase activity.
Is linoleic acid epoxygenase activity relevant to pregnancy?
Arachidonic and linoleic acid derivatives have been discussed in relation to pathological pregnancies and the human reproduction process.
How can I study linoleic acid epoxygenase activity in the lab?
Researchers can use lipidomics to measure cis-epoxyoctadecenoic acids, NADPH-dependent enzyme assays, and CRISPR knockout or overexpression models of candidate epoxygenases.
Conclusion
GO:0071614, linoleic acid epoxygenase activity, defines a specific NADPH- and oxygen-dependent catalytic function that converts linoleic acid to cis-epoxyoctadecenoic acids. Its experimental anchors include CYP2C9 in human liver microsomes, inducible activity in endothelial cells, and downstream oxylipin biology linked to inflammatory resolution and NLRP3 inflammasome activation. The activity also appears in reproductive and comparative contexts, underscoring its broad biological relevance. For researchers, the term provides a precise annotation target that can be interrogated with CRISPR knockout, point-mutation, knock-in, and overexpression models combined with lipidomic and inflammatory readouts. This combination of genetic precision and functional measurement makes GO:0071614 a tractable molecular function for mechanistic and translational studies.
References
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- 3. Askari AA et al.. 2014. Basal and inducible anti-inflammatory epoxygenase activity in endothelial cells.. Biochem Biophys Res Commun 446(2):633-7 PMID: 24631907
- 4. Gilroy DW et al.. 2016. CYP450-derived oxylipins mediate inflammatory resolution.. Proc Natl Acad Sci U S A 113(23):E3240-9 PMID: 27226306
- 5. Szczuko M et al.. 2020. The Role of Arachidonic and Linoleic Acid Derivatives in Pathological Pregnancies and the Human Reproduction Process.. Int J Mol Sci 21(24) PMID: 33348841
- 6. Oliw EH et al.. 1996. Bisallylic hydroxylation and epoxidation of polyunsaturated fatty acids by cytochrome P450.. Lipids 31(10):1003-21 PMID: 8898299
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