GO:0008392 arachidonate epoxygenase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008392 arachidonate epoxygenase activity is a molecular function defined as the NADPH- and oxygen-dependent conversion of arachidonic acid to cis-epoxyeicosatrienoic acids (EETs).
• The reaction is catalyzed primarily by cytochrome P450 epoxygenases, with CYP2J2 being the best-characterized human enzyme in the heart and vasculature.
• EETs are lipid mediators that regulate vascular tone, angiogenesis, inflammation, and cardiac function, making this pathway a therapeutic target.
• CYP2J2 and other epoxygenases also metabolize endocannabinoids and omega-3 fatty acids, broadening the biological impact of this activity.
• Inhibition or dysregulation of arachidonate epoxygenase activity has been linked to cardiac injury and altered lipid mediator profiles.
• CRISPR-based knockout, knock-in, and overexpression models are essential for dissecting the causal roles of CYP2J2 and related epoxygenases in health and disease.
Description
Arachidonate epoxygenase activity (GO:0008392) is a molecular function that catalyzes the NADPH- and oxygen-dependent epoxidation of arachidonic acid to produce cis-epoxyeicosatrienoic acids (EETs). This activity is a key branch of the cytochrome P450 (CYP) pathway of arachidonic acid metabolism, distinct from cyclooxygenase and lipoxygenase routes. The resulting EETs are bioactive lipid mediators that influence cardiovascular, renal, and inflammatory processes. Researchers study this term to understand how lipid signaling contributes to physiology and disease, and to evaluate therapeutic strategies targeting EET biosynthesis or degradation. The enzymatic activity is attributed mainly to CYP2J2 and other CYP epoxygenases, which are expressed in tissues such as heart, endothelium, and kidney. Because EETs modulate ion channels, cell proliferation, and angiogenesis, arachidonate epoxygenase activity sits at the intersection of lipid biochemistry, vascular biology, and drug discovery. This article provides a research-grade overview of the GO term, its mechanism, key genes, disease relevance, and experimental approaches, including CRISPR-based models.
arachidonate epoxygenase activity At A Glance
| GO ID | GO:0008392 |
|---|---|
| GO term | arachidonate epoxygenase activity |
| Ontology | molecular_function |
| Synonym | arachidonic acid epoxygenase activity; cytochrome P450 CYP2J5; cytochrome P450 CYP2J6 |
| Major function | Catalysis of NADPH- and oxygen-dependent conversion of arachidonic acid to cis-epoxyeicosatrienoic acid (EETs) |
| Cofactors | NADPH and molecular oxygen |
| Representative enzymes | CYP2J2, CYP2C8, CYP2C9, and other cytochrome P450 epoxygenases |
| Biological context | Lipid mediator biosynthesis; vascular tone, angiogenesis, inflammation, cardiac function |
What Is GO:0008392?
According to the Gene Ontology, arachidonate epoxygenase activity (GO:0008392) is defined as the catalysis of an NADPH- and oxygen-dependent reaction that converts arachidonic acid to a cis-epoxyeicosatrienoic acid. In simpler terms, it is the enzyme activity that adds an oxygen atom to arachidonic acid to form EETs, using NADPH as an electron donor and molecular oxygen as a substrate. This activity is a specific type of monooxygenase function carried out by cytochrome P450 enzymes, and it is distinct from other arachidonic acid-metabolizing activities such as cyclooxygenase or lipoxygenase.
Why Is arachidonate epoxygenase activity Important in Cell Biology?
Arachidonate epoxygenase activity is important because it generates EETs, which are potent lipid mediators involved in the regulation of cardiovascular, renal, and inflammatory processes. Dysregulation of this activity has been implicated in cardiac injury, hypertension, and other pathologies, making it a target for therapeutic development. Understanding the enzymes and regulatory mechanisms behind this activity can inform drug design and precision medicine approaches.
• Produces EETs, which regulate vascular tone and angiogenesis.
• Modulates cardiac function and protects against ischemia-reperfusion injury in some contexts.
• Influences inflammatory responses through EET-mediated signaling.
• Metabolizes endocannabinoids and omega-3 fatty acids, expanding its biological roles.
• Inhibition of CYP2J/EET pathway can lead to heart injury in experimental models.
• Represents a drug discovery axis for cardiovascular and metabolic diseases.
• Provides a molecular target for CRISPR-based functional studies.
• Links lipid metabolism to cell signaling and gene expression.
• May contribute to cancer biology through effects on proliferation and apoptosis.
• Serves as a biomarker or therapeutic target in precision medicine.
Molecular Mechanism of arachidonate epoxygenase activity
Substrate recognition and binding
In simple terms: The enzyme grabs arachidonic acid and holds it in place.
Cytochrome P450 epoxygenases, such as CYP2J2, bind arachidonic acid in their active site with high specificity, positioning the substrate for regio- and stereoselective epoxidation. The binding pocket accommodates the fatty acid chain and directs oxygen insertion to specific double bonds, yielding distinct EET regioisomers.
Catalytic cycle and cofactor usage
In simple terms: The enzyme uses NADPH and oxygen to add an oxygen atom to arachidonic acid.
The catalytic cycle requires NADPH as an electron donor via cytochrome P450 reductase, and molecular oxygen as the terminal electron acceptor. The enzyme inserts one oxygen atom into arachidonic acid to form a cis-epoxyeicosatrienoic acid, while the other oxygen atom is reduced to water. This monooxygenase reaction is characteristic of P450 epoxygenases.
Product formation and isomer specificity
In simple terms: Different enzymes make different EET isomers.
The reaction produces four main EET regioisomers: 5,6-, 8,9-, 11,12-, and 14,15-EET, with the relative abundance depending on the specific CYP isoform. For example, CYP2J2 preferentially generates 11,12- and 14,15-EET, which have distinct biological activities. The stereochemistry of the epoxide group also influences receptor interactions and downstream signaling.
Regulation of enzyme expression and activity
In simple terms: The body controls how much of this enzyme is made and how active it is.
Arachidonate epoxygenase activity is regulated at the level of enzyme expression, post-translational modification, and substrate availability. CYP2J2 expression can be induced or suppressed by physiological and pathological stimuli, and its activity can be modulated by inhibitors and alternative substrates. Endocannabinoids and omega-3 fatty acids can compete with arachidonic acid, altering the profile of lipid mediators produced.
Downstream signaling of EETs
In simple terms: The products of this activity act as signals in cells.
EETs produced by arachidonate epoxygenase activity act as autocrine and paracrine mediators that regulate ion channels, kinases, and transcription factors. They influence vascular tone by activating BKCa channels and contribute to angiogenesis through effects on endothelial cell proliferation and migration. These signaling actions link the enzymatic activity to complex physiological outcomes.
Key Genes Involved in GO:0008392 arachidonate epoxygenase activity
The following genes encode cytochrome P450 enzymes or related proteins that contribute to arachidonate epoxygenase activity or its regulation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CYP2J2 | Primary epoxygenase for arachidonic acid in heart and vasculature | Cardiovascular protection, drug target |
| CYP2C8 | Epoxygenase producing EETs | Vascular and renal function |
| CYP2C9 | Epoxygenase with EET-forming activity | Drug metabolism and lipid signaling |
| CYP2C19 | Epoxygenase contributing to EET pool | Cardiovascular pharmacology |
| CYP2J5 | Rodent ortholog of CYP2J2 | Animal models of cardiac function |
| CYP2J6 | Rabbit epoxygenase | Comparative studies of EET formation |
| EPHX2 | Soluble epoxide hydrolase degrades EETs | Regulates EET half-life and signaling |
| PTGS2 | Cyclooxygenase-2, alternative arachidonic acid pathway | Inflammation and crossover with EETs |
| ALOX5 | Lipoxygenase, alternative pathway | Leukotriene synthesis |
| ALOX12 | Lipoxygenase, alternative pathway | 12-HETE production |
| ALOX15 | Lipoxygenase, alternative pathway | 15-HETE production |
| PLA2G4A | Phospholipase A2 releases arachidonic acid | Substrate supply for epoxygenases |
| FAAH | Fatty acid amide hydrolase, endocannabinoid metabolism | Cross-talk with epoxygenase substrates |
| MGLL | Monoacylglycerol lipase, endocannabinoid metabolism | Provides alternative substrates |
| CNR1 | Cannabinoid receptor 1, mediates endocannabinoid effects | Signaling context |
| CNR2 | Cannabinoid receptor 2, mediates endocannabinoid effects | Inflammation |
| TRPV1 | Ion channel modulated by lipid mediators | Sensory signaling |
How Is arachidonate epoxygenase activity Regulated?
Arachidonate epoxygenase activity is regulated by multiple mechanisms, including transcriptional control of CYP epoxygenase genes, availability of arachidonic acid from phospholipase A2, and competition with other lipid substrates such as endocannabinoids and omega-3 fatty acids. Post-translational modifications and protein-protein interactions with cytochrome P450 reductase also influence catalytic efficiency. Additionally, soluble epoxide hydrolase (EPHX2) rapidly degrades EETs, thereby regulating the biological half-life of the products and the overall impact of the activity. Pharmacological inhibitors and dietary factors can modulate enzyme activity, as shown by plumbagin-induced inhibition of the CYP2J/EET pathway leading to cardiac injury.
arachidonate epoxygenase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CYP2J2 | Cardiac injury, hypertension | Cardiomyocyte-specific knockout or overexpression in mice |
| CYP2J2 | Inflammation | Endothelial cell knockout and cytokine profiling |
| EPHX2 | EET degradation, vascular tone | EPHX2 knockout mice |
| CYP2C8 | Renal and vascular function | CRISPR knockout in renal epithelial cells |
| CYP2J2 | Cancer cell proliferation | Cancer cell line knockout and xenograft |
Cardiovascular disease
Alterations in arachidonate epoxygenase activity and EET levels have been associated with hypertension, cardiac hypertrophy, and ischemia-reperfusion injury. CYP2J2 overexpression is cardioprotective in animal models, while inhibition of the pathway exacerbates cardiac damage. These findings suggest that modulating this activity could be a therapeutic strategy for cardiovascular disorders.
Inflammation and pain
EETs produced by arachidonate epoxygenase activity exhibit anti-inflammatory properties in several tissues. The omega-3 endocannabinoid epoxides, which are also generated by CYP epoxygenases, have been shown to reduce inflammation and pain. Dysregulation of this pathway may contribute to chronic inflammatory conditions.
Cancer
CYP2J2 and EETs have been implicated in tumor progression and angiogenesis, with some studies suggesting a role in cancer cell proliferation and survival. However, the effects may be context-dependent, and further research is needed to clarify the therapeutic potential of targeting this activity in oncology.
From arachidonate epoxygenase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does CYP2J2 loss alter cardiac EET levels? | Cardiomyocyte-specific CYP2J2 knockout mouse |
| What is the effect of a point mutation in the CYP2J2 active site? | CRISPR point-mutation knock-in in cell lines |
| Can tagged CYP2J2 reveal subcellular localization? | Knock-in of fluorescent tag at endogenous locus |
| Does overexpression of CYP2J2 protect against ischemia? | Transgenic overexpression in mice |
| Which genes regulate EET signaling? | CRISPR library screening in endothelial cells |
| How does EPHX2 inhibition affect EET half-life? | EPHX2 knockout or inhibitor treatment |
How to Study the arachidonate epoxygenase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| LC-MS/MS lipidomics | EET regioisomer levels | Quantifying epoxygenase activity in cells/tissues |
| Enzyme activity assay | Conversion of arachidonic acid to EETs | Kinetic analysis and inhibitor testing |
| qRT-PCR | mRNA expression of CYP epoxygenases | Gene expression profiling |
| RNA-seq | Transcriptome-wide changes | Pathway analysis after knockout |
| Western blot | Protein expression of CYP2J2 | Validation of overexpression or knockout |
| Immunofluorescence | Subcellular localization | Tagged knock-in studies |
| CRISPR screen | Gene essentiality or modifier identification | Discovery of regulators of EET signaling |
| Animal models | In vivo cardiac function | Testing therapeutic potential |
Lipidomics and mass spectrometry
Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the gold standard for quantifying EETs and other oxylipins produced by arachidonate epoxygenase activity. This method allows researchers to profile regioisomers and assess the impact of genetic or pharmacological perturbations.
Enzymatic activity assays
In vitro activity assays using recombinant CYP enzymes or microsomes, with arachidonic acid as substrate and NADPH as cofactor, can directly measure epoxygenase activity. These assays are useful for kinetic studies and inhibitor screening.
Gene expression analysis
Quantitative PCR and RNA-seq can measure the expression of CYP2J2 and other epoxygenases in tissues or cells. This helps link transcriptional regulation to activity levels.
CRISPR-based functional genomics
CRISPR knockout, knock-in, and overexpression models enable causal testing of candidate genes in the epoxygenase pathway. Pooled CRISPR screens can identify modifiers of EET production or signaling.
How CRISPR Can Be Used to Study GO:0008392 arachidonate epoxygenase activity
Knockout
CRISPR knockout of CYP2J2 or other epoxygenases eliminates arachidonate epoxygenase activity, allowing researchers to assess the contribution of specific enzymes to EET production and downstream phenotypes. Cardiomyocyte-specific knockout models have been used to study cardiac function.
Point Mutation
Point mutations in the active site of CYP2J2 can be introduced via CRISPR to dissect catalytic residues and substrate specificity. Such models help distinguish between enzyme activity and other functions of the protein.
Knock-in
Knock-in of epitope tags or fluorescent proteins at the endogenous CYP2J2 locus enables real-time visualization and quantification of the enzyme without overexpression artifacts. This approach is valuable for studying subcellular localization and dynamics.
Overexpression
CRISPR activation or transgenic overexpression of CYP2J2 can boost arachidonate epoxygenase activity, providing a gain-of-function model to test protective or detrimental effects in disease contexts. Overexpression in cell lines or animal models is widely used to study EET-mediated signaling.
How EDITGENE Supports arachidonate epoxygenase activity Research
Researchers studying arachidonate epoxygenase activity-related genes often need to determine whether a candidate gene is causally involved in EET production, signaling, or disease phenotypes. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell and animal models, enabling rigorous functional studies of this pathway.
Contact EDITGENE today to design your custom CRISPR model for arachidonate epoxygenase activity research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CYP2E1 Knockout HEK293 Cell Line | EDJ-KQ958 | Human | 1571 | Details Get a Quote |
| CYP2C9 Knockout HEK293 Cell Line | EDJ-KQ2527 | Human | 1559 | Details Get a Quote |
| CYP2S1 Knockout HEK293 Cell Line | EDJ-KQ2870 | Human | 29785 | Details Get a Quote |
| CYP2A6 Knockout HEK293 Cell Line | EDJ-KQ3586 | Human | 1548 | Details Get a Quote |
| CYP2F1 Knockout HEK293 Cell Line | EDJ-KQ3671 | Human | 1572 | Details Get a Quote |
| CYP2A7 Knockout HEK293 Cell Line | EDJ-KQ4395 | Human | 1549 | Details Get a Quote |
| CYP2A13 Knockout HEK293 Cell Line | EDJ-KQ4396 | Human | 1553 | Details Get a Quote |
| CYP2B6 Knockout HEK293 Cell Line | EDJ-KQ4397 | Human | 1555 | Details Get a Quote |
| CYP2C8 Knockout HEK293 Cell Line | EDJ-KQ4398 | Human | 1558 | Details Get a Quote |
| CYP2C18 Knockout HEK293 Cell Line | EDJ-KQ4403 | Human | 1562 | Details Get a Quote |
| CYP2J2 Knockout HEK293 Cell Line | EDJ-KQ4405 | Human | 1573 | Details Get a Quote |
| CYP4A11 Knockout HEK293 Cell Line | EDJ-KQ4408 | Human | 1579 | Details Get a Quote |
| CYP4F2 Knockout HEK293 Cell Line | EDJ-KQ6270 | Human | 8529 | Details Get a Quote |
| CYP4F12 Knockout HEK293 Cell Line | EDJ-KQ12303 | Human | 66002 | Details Get a Quote |
| CYP2J2 Knockout HCT 116 Cell Line | EDJ-KQ26930 | Human | 1573 | Details Get a Quote |
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Frequently Asked Questions About arachidonate epoxygenase activity
What is arachidonate epoxygenase activity?
Arachidonate epoxygenase activity (GO:0008392) is a molecular function that catalyzes the NADPH- and oxygen-dependent conversion of arachidonic acid to cis-epoxyeicosatrienoic acids (EETs).
What genes are involved in arachidonate epoxygenase activity?
The main genes include CYP2J2, CYP2C8, CYP2C9, and other cytochrome P450 epoxygenases, as well as EPHX2 which degrades the products.
Which enzyme is the primary epoxygenase in the heart?
CYP2J2 is the predominant epoxygenase in cardiomyocytes and is a major source of EETs in the heart.
What are EETs and what do they do?
EETs are epoxyeicosatrienoic acids, lipid mediators that regulate vascular tone, angiogenesis, inflammation, and cardiac function.
How is arachidonate epoxygenase activity regulated?
It is regulated by enzyme expression, substrate availability, competition with other lipids, and degradation of EETs by soluble epoxide hydrolase.
What diseases are associated with arachidonate epoxygenase activity?
It has been linked to cardiovascular disease, inflammation, and cancer, among others.
How can I study arachidonate epoxygenase activity in the lab?
Common methods include LC-MS/MS lipidomics, enzyme activity assays, gene expression analysis, and CRISPR-based models.
What CRISPR models are available for CYP2J2?
Knockout, point mutation, knock-in, and overexpression models can be generated to study CYP2J2 function.
Does CYP2J2 metabolize endocannabinoids?
Yes, CYP2J2 and other P450 epoxygenases can metabolize endocannabinoids, producing epoxy derivatives with biological activity.
Can inhibition of arachidonate epoxygenase activity cause heart injury?
Yes, plumbagin inhibition of the CYP2J/EET pathway has been shown to lead to heart injury in cardiac organoids and rats.
Conclusion
Arachidonate epoxygenase activity (GO:0008392) is a critical molecular function that generates EETs, which play diverse roles in cardiovascular, inflammatory, and other biological processes. Understanding its mechanism, regulation, and disease relevance is essential for developing targeted therapies. CRISPR-based models and advanced analytical methods provide powerful tools to dissect this pathway and identify new therapeutic opportunities.
References
- 1. Valencia R et al.. 2022. Cardiomyocyte-specific CYP2J2 and its therapeutic implications.. Expert Opin Drug Metab Toxicol 18(7-8):423-439 PMID: 35997132
- 2. Das A et al.. 2020. CYP2J2 Molecular Recognition: A New Axis for Therapeutic Design.. Pharmacol Ther 215:107601 PMID: 32534953
- 3. Sisignano M et al.. 2020. Exploring CYP2J2: lipid mediators, inhibitors and therapeutic implications.. Drug Discov Today 25(9):1744-1753 PMID: 32652311
- 4. Zelasko S et al.. 2015. Endocannabinoid metabolism by cytochrome P450 monooxygenases.. Prostaglandins Other Lipid Mediat 116-117:112-23 PMID: 25461979
- 5. McDougle DR et al.. 2017. Anti-inflammatory ω-3 endocannabinoid epoxides.. Proc Natl Acad Sci U S A 114(30):E6034-E6043 PMID: 28687674
- 6. Liang C et al.. 2025. Plumbagin inhibits CYP2J/EETs metabolic pathway and leads to heart injury in cardiac organoids and rats.. Biochem Pharmacol 242(Pt 1):117282 PMID: 40885320
- 7. Spector AA. 2009. Arachidonic acid cytochrome P450 epoxygenase pathway.. J Lipid Res 50 Suppl(Suppl):S52-6 PMID: 18952572
- 8. Fleming I. 2007. Epoxyeicosatrienoic acids, cell signaling and angiogenesis.. Prostaglandins Other Lipid Mediat 82(1-4):60-7 PMID: 17164133
