GO:0047017 prostaglandin F synthase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0047017 (prostaglandin F synthase activity) is a molecular function defined by the NADPH-dependent reduction of prostaglandin D2 to prostaglandin F2alpha, with concomitant oxidation of NADPH to NADP+.
• The reaction is catalyzed by aldo-keto reductase (AKR) enzymes, most notably AKR1C3 in humans, which functions as a prostaglandin F synthase and also as a type 5 17beta-hydroxysteroid dehydrogenase.
• Prostaglandin F synthase activity is involved in the biosynthesis of PGF2alpha, a lipid mediator that regulates smooth muscle contraction, luteolysis, and inflammation.
• Dysregulated prostaglandin F synthase activity has been implicated in cancer, endocrine disorders, and ocular hypertension, making it a target for drug discovery [3,4,8].
• Structural and kinetic studies have revealed the catalytic mechanism, cofactor specificity, and inhibitor binding of prostaglandin F synthase, providing a basis for rational inhibitor design [1,6,7].
• CRISPR-based models (knockout, point mutation, knock-in, overexpression) enable precise interrogation of prostaglandin F synthase genes in disease and development [3,4].
Description
Prostaglandin F synthase activity (GO:0047017) is a molecular function that catalyzes the NADPH-dependent reduction of prostaglandin D2 (PGD2) to prostaglandin F2alpha (PGF2alpha), a key step in the biosynthesis of this bioactive lipid mediator. The reaction is formally described as NADP+ + prostaglandin F2alpha = H+ + NADPH + prostaglandin D2, indicating reversibility under certain conditions. This activity is essential for diverse physiological processes, including smooth muscle contraction, luteolysis, and modulation of inflammation. In humans, the enzyme primarily responsible for this activity is AKR1C3 (aldo-keto reductase family 1 member C3), also known as type 5 17beta-hydroxysteroid dehydrogenase (17beta-HSD5) or prostaglandin F synthase. AKR1C3 is a multifunctional enzyme that also catalyzes the reduction of steroids and other substrates, linking prostaglandin and steroid hormone metabolism. Because of its role in producing PGF2alpha, which promotes cell proliferation and hormone signaling, AKR1C3 has attracted attention as a therapeutic target in cancer and endocrine disorders [3,4]. Understanding the molecular details of prostaglandin F synthase activity is therefore critical for developing selective inhibitors and for interpreting its contributions to disease. This article provides a comprehensive overview of the GO term, its catalytic mechanism, key genes, disease associations, and modern research methods, including CRISPR-based models.
prostaglandin F synthase activity At A Glance
| GO ID | GO:0047017 |
|---|---|
| GO term | prostaglandin F synthase activity |
| Ontology | molecular_function |
| Synonym | PGD2 11-ketoreductase activity; PGF2alpha synthetase activity; prostaglandin 11-keto reductase activity |
| Major function | Catalyzes the NADPH-dependent reduction of prostaglandin D2 to prostaglandin F2alpha |
| Reaction | NADP+ + prostaglandin F2alpha = H+ + NADPH + prostaglandin D2 |
| Cofactor | NADPH (reducing agent) |
| Representative enzyme | AKR1C3 (aldo-keto reductase family 1 member C3) in humans |
What Is GO:0047017?
According to the Gene Ontology, prostaglandin F synthase activity (GO:0047017) is defined as the catalysis of the reaction: NADP+ + prostaglandin F2alpha = H+ + NADPH + prostaglandin D2. In other words, it is the oxidoreductase activity that interconverts prostaglandin D2 and prostaglandin F2alpha using NADPH as a cofactor. This activity is synonymous with PGD2 11-ketoreductase, PGF2alpha synthetase, and prostaglandin 11-keto reductase, reflecting its role in reducing the 11-keto group of PGD2 to a hydroxyl group in PGF2alpha.
Why Is prostaglandin F synthase activity Important in Cell Biology?
Prostaglandin F synthase activity is critical for the biosynthesis of PGF2alpha, a lipid mediator that regulates smooth muscle contraction, luteolysis, and inflammation. In humans, AKR1C3 is overexpressed in several cancers and contributes to tumor proliferation and drug resistance, making it a promising therapeutic target [3,4]. Additionally, the enzyme is involved in endocrine disorders such as polycystic ovary syndrome and endometriosis, and its inhibition is being explored for treating ocular hypertension [3,8]. Thus, understanding this activity is essential for both basic biology and translational medicine.
• Produces PGF2alpha, a key regulator of smooth muscle contraction and luteolysis.
• AKR1C3 overexpression is associated with breast, prostate, and endometrial cancers [3,4].
• Contributes to steroid hormone metabolism via 17beta-HSD activity, linking prostaglandin and steroid pathways.
• Inhibition of AKR1C3 reduces proliferation in breast cancer cell lines.
• Bimatoprost, a prodrug used for glaucoma, inhibits prostaglandin F synthase, affecting ocular pressure.
• Genetic variations in AKR1C3 are linked to endocrine disorders and altered drug metabolism.
• Provides a target for anti-inflammatory and anti-proliferative therapies [3,4].
• Structural knowledge enables rational design of selective inhibitors [6,7].
Molecular Mechanism of prostaglandin F synthase activity
Substrate Binding and Cofactor Specificity
In simple terms: The enzyme grabs PGD2 and NADPH, positioning them for a chemical reaction.
Prostaglandin F synthase binds its substrate, prostaglandin D2 (PGD2), and the cofactor NADPH in a stereospecific manner. The enzyme belongs to the aldo-keto reductase superfamily, which typically uses NADPH as the hydride donor. Kinetic studies of bovine lung prostaglandin F synthase revealed an ordered bi-bi mechanism where NADPH binds first, followed by PGD2, and the products are released in reverse order. The enzyme exhibits high specificity for the 11-keto group of PGD2, reducing it to an 11alpha-hydroxyl group to form PGF2alpha.
Catalytic Mechanism and Stereochemistry
In simple terms: A hydride from NADPH is transferred to PGD2, converting it to PGF2alpha with a specific 3D shape.
The catalytic mechanism involves the transfer of a hydride ion from the nicotinamide ring of NADPH to the C11 keto group of PGD2, resulting in the formation of PGF2alpha. This reduction is stereospecific, yielding the 11alpha-hydroxy epimer. The reaction is reversible, and the enzyme can also catalyze the oxidation of PGF2alpha back to PGD2 in the presence of NADP+. Site-directed mutagenesis and structural studies of human AKR1C3 have identified key residues (e.g., Tyr55, His117) that act as general acid/base catalysts and stabilize the transition state.
Enzyme Structure and Active Site Architecture
In simple terms: The enzyme has a pocket that fits PGD2 and NADPH perfectly, like a lock and key.
Crystal structures of human prostaglandin F synthase (AKR1C3) reveal a typical (alpha/beta)8-barrel fold with a conserved active site. The active site contains a catalytic tetrad (Tyr55, His117, Asp50, and Lys84) that facilitates proton transfer and stabilizes the substrate. The cofactor NADPH is bound in an extended conformation, and the substrate binding pocket is hydrophobic, accommodating the prostaglandin backbone. Structural analyses of mutant forms mimicking active conformations have provided insights into conformational changes during catalysis.
Inhibition and Regulation
In simple terms: Certain drugs can block the enzyme, reducing PGF2alpha production.
Prostaglandin F synthase activity can be inhibited by nonsteroidal anti-inflammatory drugs (NSAIDs) and specific AKR1C3 inhibitors. Bimatoprost, a synthetic prostaglandin analog used to treat glaucoma, was identified as a potent inhibitor of prostaglandin F synthase, with an IC50 in the low micromolar range. Additionally, cholest-4-ene-3,6-dione inhibits AKR1C3 and exhibits anti-proliferative activity in MCF-7 breast cancer cells. Regulation of enzyme expression occurs at the transcriptional level, with AKR1C3 induced by cytokines and growth factors in cancer cells.
Key Genes Involved in GO:0047017 prostaglandin F synthase activity
The following genes encode enzymes with prostaglandin F synthase activity or are closely related to its function and regulation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| AKR1C3 | Primary human prostaglandin F synthase; also 17beta-HSD5 | Overexpressed in cancers; target for inhibitors [3,4] |
| AKR1C1 | Aldo-keto reductase with 20alpha-HSD activity; may contribute to PGF synthesis | Isoform-specific functions in steroid metabolism |
| AKR1C2 | Aldo-keto reductase; 3alpha-HSD activity | Potential redundancy in prostaglandin reduction |
| AKR1C4 | Liver-specific aldo-keto reductase | Role in hepatic prostaglandin metabolism |
| AKR1B1 | Aldose reductase; may reduce prostaglandins | Implicated in diabetic complications |
| PTGDS | Prostaglandin D2 synthase; produces PGD2 substrate | Upstream of PGF synthase in arachidonic acid cascade |
| PTGS1 | Cyclooxygenase-1; synthesizes prostaglandin H2 | Target of NSAIDs; affects substrate availability |
| PTGS2 | Cyclooxygenase-2; inducible in inflammation | Links inflammation to PGF2alpha production |
| CBR1 | Carbonyl reductase 1; reduces prostaglandins | Alternative pathway for PGF2alpha synthesis |
| AKR1A1 | Aldehyde reductase; broad substrate specificity | May contribute to prostaglandin metabolism |
| SRD5A1 | Steroid 5alpha-reductase; not directly PGF synthase | Interacts with AKR1C3 in steroid pathways |
| HSD17B5 | Synonym for AKR1C3 | Same enzyme; context-dependent naming |
| NRF2 | Transcription factor regulating antioxidant genes | May regulate AKR1C3 expression |
| NFKB1 | Inflammatory transcription factor | Induces AKR1C3 in cancer |
| IL6 | Cytokine that upregulates AKR1C3 | Links inflammation to PGF synthase activity |
| EGFR | Growth factor receptor; signals to AKR1C3 | Therapeutic target in cancers |
| AR | Androgen receptor; interacts with AKR1C3 in prostate | Role in prostate cancer progression |
How Is prostaglandin F synthase activity Regulated?
Prostaglandin F synthase activity is regulated at multiple levels. Transcriptional regulation of AKR1C3 is mediated by inflammatory cytokines such as IL-6 and growth factors via NF-kB and EGFR signaling pathways. Post-translational modifications, including phosphorylation, may affect enzyme activity, although specific sites remain to be fully characterized. The enzyme's activity is also influenced by the availability of NADPH and the redox state of the cell. Additionally, competitive inhibition by endogenous steroids and exogenous drugs modulates its function in vivo [3,8].
prostaglandin F synthase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| AKR1C3 | Breast cancer proliferation | MCF-7 knockout or overexpression |
| AKR1C3 | Prostate cancer androgen independence | LNCaP point mutation models |
| AKR1C3 | Endometriosis and PCOS | Primary endometrial stromal cells with CRISPR KO |
| AKR1C3 | Glaucoma (drug target) | Ocular cell lines with knock-in of mutant enzyme |
| AKR1C3 | Chemoresistance | Cancer cell lines with overexpression |
Cancer
AKR1C3, the primary enzyme with prostaglandin F synthase activity, is overexpressed in several malignancies, including breast, prostate, and endometrial cancers. Its ability to produce PGF2alpha, which promotes cell proliferation and angiogenesis, contributes to tumor growth. Inhibition of AKR1C3 with cholest-4-ene-3,6-dione reduces proliferation in MCF-7 breast cancer cells, suggesting a therapeutic strategy. In prostate cancer, AKR1C3 contributes to intratumoral androgen synthesis and resistance to anti-androgen therapies.
Endocrine Disorders
Dysregulated prostaglandin F synthase activity has been linked to endocrine disorders such as polycystic ovary syndrome (PCOS) and endometriosis. Elevated PGF2alpha levels can cause abnormal uterine contractions and pain. AKR1C3 also functions as 17beta-HSD5, converting androstenedione to testosterone, which may exacerbate hyperandrogenism in PCOS.
Ocular Hypertension and Glaucoma
Prostaglandin F synthase is involved in the metabolism of prostaglandin analogs used to treat glaucoma. Bimatoprost, a prodrug, is hydrolyzed to a free acid that inhibits prostaglandin F synthase, thereby increasing aqueous humor outflow and reducing intraocular pressure. This highlights the enzyme as a pharmacological target in ophthalmology.
From prostaglandin F synthase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of AKR1C3 reduce PGF2alpha production? | CRISPR knockout in cancer cell lines |
| How does a specific point mutation affect catalytic efficiency? | Point mutation knock-in (e.g., Tyr55Phe) |
| Can a tagged enzyme be used for localization studies? | Knock-in of FLAG- or GFP-tagged AKR1C3 |
| Does overexpression of AKR1C3 promote proliferation? | Stable overexpression in MCF-7 cells |
| What is the effect of inhibitor on enzyme activity? | In vitro assay with purified recombinant enzyme |
| Does AKR1C3 regulate steroidogenesis? | Knockout in adrenal or gonadal cell lines |
How to Study the prostaglandin F synthase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| NADPH oxidation assay | Enzyme activity | Kinetic characterization |
| LC-MS/MS | PGF2alpha and PGD2 levels | Quantification in cells |
| X-ray crystallography | 3D structure | Active site analysis |
| Site-directed mutagenesis | Effect of point mutations | Mechanistic studies |
| RNA-seq | Gene expression | Transcriptional regulation |
| CRISPR knockout | Loss-of-function phenotype | Cancer proliferation |
| Western blot | Protein expression | Validation of overexpression |
| Inhibitor screening | IC50 values | Drug discovery |
Enzyme Activity Assays
Prostaglandin F synthase activity is typically measured using spectrophotometric assays that monitor the oxidation of NADPH at 340 nm or by LC-MS/MS quantification of PGF2alpha formation [1,8]. Kinetic parameters (Km, Vmax) are determined by varying substrate concentrations. These assays are essential for characterizing inhibitors and mutants.
Structural Biology
X-ray crystallography and cryo-EM have been used to solve the structures of human AKR1C3 in complex with NADPH and inhibitors. These studies reveal the active site architecture and guide mutagenesis. Recent work on active form-mimicking mutants provides insights into conformational dynamics.
Gene Expression Analysis
RNA-seq and qRT-PCR are used to quantify AKR1C3 mRNA levels in tissues and cell lines. This is important for understanding transcriptional regulation in cancer and endocrine disorders.
CRISPR Screening
Genome-wide CRISPR knockout screens can identify genes that modulate PGF2alpha production or sensitivity to AKR1C3 inhibitors. Such screens link prostaglandin F synthase activity to broader cellular pathways.
How CRISPR Can Be Used to Study GO:0047017 prostaglandin F synthase activity
Knockout
CRISPR-Cas9 knockout of AKR1C3 in cancer cell lines (e.g., MCF-7) reduces PGF2alpha production and inhibits proliferation, validating its role in tumor growth. Knockout models are also used to study steroid hormone synthesis.
Point Mutation
Point mutations in catalytic residues (e.g., Tyr55Phe) can be introduced via CRISPR to dissect the mechanism of hydride transfer and proton donation. Such models help distinguish between prostaglandin F synthase and 17beta-HSD activities.
Knock-in
Knock-in of tagged AKR1C3 (e.g., FLAG or GFP) allows for localization and interaction studies. Knock-in of disease-associated variants can model altered enzyme function in endocrine disorders.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of AKR1C3 is used to study the consequences of elevated prostaglandin F synthase activity, such as increased PGF2alpha and enhanced cell migration.
How EDITGENE Supports prostaglandin F synthase activity Research
Researchers studying prostaglandin F synthase activity-related genes often need to determine whether a candidate gene is causally involved in PGF2alpha production, cancer proliferation, or endocrine regulation. EDITGENE provides a comprehensive suite of CRISPR services to create precise cellular models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for prostaglandin F synthase activity research.
Frequently Asked Questions About prostaglandin F synthase activity
What is prostaglandin F synthase activity?
It is the enzyme activity that catalyzes the NADPH-dependent reduction of prostaglandin D2 to prostaglandin F2alpha, encoded by GO:0047017.
What genes are involved in prostaglandin F synthase activity?
The primary human gene is AKR1C3, which encodes an aldo-keto reductase also known as type 5 17beta-hydroxysteroid dehydrogenase.
What is the reaction catalyzed by prostaglandin F synthase?
The reaction is NADP+ + prostaglandin F2alpha = H+ + NADPH + prostaglandin D2, which is reversible.
How is prostaglandin F synthase activity measured?
It is commonly measured by NADPH oxidation at 340 nm or by LC-MS/MS quantification of PGF2alpha [1,8].
What diseases are associated with prostaglandin F synthase?
It is implicated in breast and prostate cancer, endocrine disorders like PCOS, and glaucoma [3,4,8].
What is the role of AKR1C3 in cancer?
AKR1C3 is overexpressed in several cancers and promotes proliferation and drug resistance, making it a therapeutic target [3,4].
Can prostaglandin F synthase be inhibited?
Yes, inhibitors such as bimatoprost and cholest-4-ene-3,6-dione have been shown to inhibit the enzyme [4,8].
What is the structure of prostaglandin F synthase?
Human AKR1C3 has an (alpha/beta)8-barrel fold with a catalytic tetrad of Tyr55, His117, Asp50, and Lys84.
How can CRISPR be used to study prostaglandin F synthase?
CRISPR knockout, point mutation, knock-in, and overexpression models allow precise interrogation of gene function in disease [3,4].
What are the synonyms for prostaglandin F synthase activity?
Synonyms include PGD2 11-ketoreductase, PGF2alpha synthetase, and prostaglandin 11-keto reductase.
Conclusion
Prostaglandin F synthase activity (GO:0047017) is a key enzymatic function in the biosynthesis of PGF2alpha, with critical roles in inflammation, reproduction, and cancer. The enzyme AKR1C3 is the primary human prostaglandin F synthase and a promising drug target. Advances in structural biology and CRISPR-based models are accelerating our understanding of its mechanism and disease relevance. EDITGENE offers comprehensive CRISPR services to support research on this important pathway.
References
- 1. Barski OA et al.. 1993. Kinetic mechanism of ketoreductase activity of prostaglandin F synthase from bovine lung.. FEBS Lett 320(2):107-10 PMID: 8458424
- 3. Penning TM. 2019. AKR1C3 (type 5 17β-hydroxysteroid dehydrogenase/prostaglandin F synthase): Roles in malignancy and endocrine disorders.. Mol Cell Endocrinol 489:82-91 PMID: 30012349
- 4. Sali VK et al.. 2020. Type 5 17-hydroxysteroid dehydrogenase/prostaglandin F synthase (AKR1C3) inhibition and potential anti-proliferative activity of cholest-4-ene-3,6-dione in MCF-7 breast cancer cells.. Steroids 159:108638 PMID: 32209376
- 6. Cheon SW et al.. 2026. Structural and Biophysical Analyses of Human Prostamide/Prostaglandin F Synthase with Two Active Form-Mimicking Mutations.. Biomolecules 16(2) PMID: 41750332
- 7. Komoto J et al.. 2004. Crystal structure of human prostaglandin F synthase (AKR1C3).. Biochemistry 43(8):2188-98 PMID: 14979715
- 8. Koda N et al.. 2004. Synthesis of prostaglandin F ethanolamide by prostaglandin F synthase and identification of Bimatoprost as a potent inhibitor of the enzyme: new enzyme assay method using LC/ESI/MS.. Arch Biochem Biophys 424(2):128-36 PMID: 15047184
