GO:0047598 7-dehydrocholesterol reductase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0047598 (7-dehydrocholesterol reductase activity) catalyzes the NADPH-dependent reduction of 7-dehydrocholesterol to cholesterol, the final step in the Bloch cholesterol biosynthesis pathway.
• The enzyme is encoded by DHCR7; loss-of-function mutations cause Smith-Lemli-Opitz syndrome, a developmental disorder with elevated 7-dehydrocholesterol and low cholesterol.
• 7-dehydrocholesterol (7-DHC) acts as an endogenous suppressor of ferroptosis, so DHCR7 inhibition or deficiency can protect cells from lipid peroxidation-driven death.
• DHCR7 is a host dependency factor for viruses such as EV-A71; its inhibition boosts IRF3 activation and interferon responses to eliminate infection.
• In cancer, DHCR7 is induced by m6A modification and promotes bladder cancer metastasis via cholesterol synthesis and cAMP signaling.
• Cholesterol overload in macrophages inhibits DHCR7, linking this activity to metabolic dysfunction-associated steatohepatitis (MASH).
Description
7-dehydrocholesterol reductase activity (GO:0047598) is a molecular function that catalyzes the final step of cholesterol biosynthesis: the conversion of 7-dehydrocholesterol (7-DHC) to cholesterol using NADPH as a reducing cofactor. This reaction is essential for maintaining cellular cholesterol homeostasis and for preventing the accumulation of the highly reactive sterol intermediate 7-DHC. The enzyme responsible, DHCR7, is a membrane-bound sterol reductase localized to the endoplasmic reticulum. Researchers study this activity because it sits at the intersection of cholesterol metabolism, ferroptosis regulation, antiviral immunity, and cancer progression. Dysregulation of 7-dehydrocholesterol reductase activity leads to Smith-Lemli-Opitz syndrome, a severe developmental disorder, and has been implicated in metabolic liver disease and tumor metastasis. Understanding its mechanism and regulation is therefore critical for both basic cell biology and therapeutic development.
7-dehydrocholesterol reductase activity At A Glance
| GO ID | GO:0047598 |
|---|---|
| GO term | 7-dehydrocholesterol reductase activity |
| Ontology | molecular_function |
| Synonym | 7-DHC reductase activity; cholesterol:NADP+ delta7-oxidoreductase activity; sterol delta7-reductase activity; sterol Delta(7)-reductase activity |
| Major function | Reduction of 7-dehydrocholesterol to cholesterol, the terminal step of cholesterol biosynthesis |
| Cofactor | NADPH (reducing agent); NADP+ is produced |
| Substrate | 7-dehydrocholesterol |
| Product | Cholesterol |
| Cellular location | Endoplasmic reticulum membrane |
| Associated gene | DHCR7 (7-dehydrocholesterol reductase) |
What Is GO:0047598?
7-dehydrocholesterol reductase activity (GO:0047598) is defined by the QuickGO ontology as the catalysis of the reaction: cholesterol + NADP+ = 7-dehydrocholesterol + H+ + NADPH. In the physiological direction, the enzyme reduces the C7-C8 double bond of 7-dehydrocholesterol to yield cholesterol, consuming NADPH and releasing NADP+. This activity is synonymous with 7-DHC reductase, cholesterol:NADP+ delta7-oxidoreductase, and sterol delta7-reductase.
Why Is 7-dehydrocholesterol reductase activity Important in Cell Biology?
7-dehydrocholesterol reductase activity is important because it controls the last committed step of cholesterol synthesis and simultaneously eliminates 7-DHC, a sterol that can drive ferroptosis and modulate immune signaling. Its dysfunction causes Smith-Lemli-Opitz syndrome, a multisystem developmental disorder, and its inhibition or overexpression is linked to viral infection, liver disease, and cancer metastasis. Thus, measuring and manipulating this activity is central to understanding lipid metabolism in health and disease.
• Maintains cholesterol homeostasis by completing the Bloch pathway.
• Prevents accumulation of 7-DHC, a reactive sterol that suppresses ferroptosis.
• Loss-of-function mutations in DHCR7 cause Smith-Lemli-Opitz syndrome.
• DHCR7 inhibition enhances IRF3 activation and interferon responses against viral infection.
• m6A-mediated induction of DHCR7 promotes bladder cancer metastasis via cholesterol synthesis and cAMP signaling.
• Cholesterol overload in macrophages inhibits DHCR7, contributing to MASH.
• Serves as a therapeutic target for antiviral and anticancer strategies.
• Provides a biomarker for disorders of cholesterol synthesis.
What Happens During 7-dehydrocholesterol reductase activity?
Substrate binding and cofactor recruitment
In simple terms: The enzyme grabs 7-dehydrocholesterol and a helper molecule called NADPH.
DHCR7 binds 7-dehydrocholesterol in the endoplasmic reticulum membrane and recruits NADPH as the electron donor for the reduction reaction. The enzyme belongs to the sterol reductase family and uses a conserved catalytic mechanism to transfer hydride to the sterol substrate.
Catalytic reduction of the C7-C8 double bond
In simple terms: The enzyme removes a double bond from 7-dehydrocholesterol to make cholesterol.
The catalytic step reduces the C7-C8 double bond of 7-dehydrocholesterol, converting it to cholesterol with concomitant oxidation of NADPH to NADP+ and release of H+. This reaction is the final step in the Bloch cholesterol biosynthesis pathway.
Product release and metabolic integration
In simple terms: Cholesterol is released and used by the cell, while 7-DHC levels drop.
Cholesterol produced by DHCR7 is incorporated into membranes or further metabolized, and the reduction of 7-DHC prevents its accumulation. Loss of DHCR7 activity leads to elevated 7-DHC and reduced cholesterol, as seen in Smith-Lemli-Opitz syndrome.
Regulation by sterol status and disease signals
In simple terms: The enzyme's activity changes depending on how much cholesterol the cell has and on stress signals.
DHCR7 expression and activity are influenced by cholesterol availability and by pathological states such as cholesterol overload in macrophages, which inhibits DHCR7 and promotes MASH. In cancer, m6A modification induces DHCR7 to stimulate cholesterol synthesis and cAMP signaling.
Key Genes Involved in GO:0047598 7-dehydrocholesterol reductase activity
The following genes and proteins are directly or functionally linked to 7-dehydrocholesterol reductase activity (GO:0047598) based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DHCR7 | Encodes 7-dehydrocholesterol reductase, the enzyme catalyzing GO:0047598 | Mutations cause Smith-Lemli-Opitz syndrome; target in cancer and antiviral studies |
| DHCR24 | Catalyzes the final step of the Bloch pathway in some contexts; related sterol reductase | May compensate or interact in cholesterol synthesis |
| SC5D | Sterol-C5-desaturase, upstream of DHCR7 in cholesterol biosynthesis | Provides substrate flux to DHCR7 |
| EBP | Emopamil binding protein, involved in sterol isomerization upstream of DHCR7 | Cholesterol biosynthesis pathway component |
| NSDHL | NAD(P)-dependent steroid dehydrogenase-like, upstream in the pathway | Cholesterol synthesis and developmental disorders |
| MSMO1 | Methylsterol monooxygenase 1, upstream of DHCR7 | Cholesterol biosynthesis |
| FDFT1 | Squalene synthase, early cholesterol biosynthesis enzyme | Pathway context for DHCR7 |
| HMGCR | Rate-limiting enzyme of cholesterol synthesis | Coordinates with DHCR7 in sterol homeostasis |
| SREBF2 | Transcription factor regulating cholesterol biosynthesis genes including DHCR7 | Regulates DHCR7 expression |
| IRF3 | Interferon regulatory factor 3, activated when DHCR7 is inhibited | Links DHCR7 to antiviral immunity |
| IFNB1 | Interferon beta, induced upon DHCR7 inhibition | Antiviral response |
| GPX4 | Glutathione peroxidase 4, ferroptosis regulator antagonized by 7-DHC | 7-DHC suppresses ferroptosis |
| ACSL4 | Acyl-CoA synthetase long-chain family member 4, promotes ferroptosis | Lipid peroxidation context |
| m6A machinery (METTL3/METTL14) | RNA methylation writers that modify DHCR7 mRNA | Induction of DHCR7 in bladder cancer |
| cAMP signaling components | Downstream effectors of DHCR7-driven cholesterol synthesis | Promote bladder cancer metastasis |
| EV-A71 viral proteins | Viral replication depends on DHCR7 activity | Targeting DHCR7 inhibits EV-A71 |
| Macrophage cholesterol transporters | Mediate cholesterol overload that inhibits DHCR7 | MASH pathogenesis |
| 7-DHC (metabolite) | Substrate of DHCR7 and endogenous ferroptosis suppressor | Biomarker and therapeutic target |
How Is 7-dehydrocholesterol reductase activity Regulated?
7-dehydrocholesterol reductase activity is regulated at multiple levels. Transcription of DHCR7 is controlled by sterol regulatory element-binding protein 2 (SREBP-2) in response to cellular cholesterol status. In macrophages, cholesterol overload inhibits DHCR7, linking lipid loading to metabolic dysfunction-associated steatohepatitis. In cancer, m6A RNA methylation induces DHCR7 expression, stimulating cholesterol synthesis and cAMP signaling to promote metastasis. Additionally, inhibition of DHCR7 activates IRF3 and interferon responses, indicating that its activity is integrated with innate immune signaling.
7-dehydrocholesterol reductase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DHCR7 | Smith-Lemli-Opitz syndrome | Patient-derived fibroblasts or DHCR7 knockout cell lines |
| DHCR7 | Ferroptosis suppression | GPX4-deficient or ACSL4-overexpressing cells treated with DHCR7 inhibitors |
| DHCR7 | EV-A71 infection | DHCR7 knockout or knockdown cells infected with EV-A71 |
| DHCR7 | Bladder cancer metastasis | m6A-modified bladder cancer cell lines with DHCR7 overexpression or knockout |
| DHCR7 | Metabolic dysfunction-associated steatohepatitis | Macrophage cholesterol overload models |
Smith-Lemli-Opitz syndrome
Biallelic loss-of-function mutations in DHCR7 cause Smith-Lemli-Opitz syndrome, characterized by elevated 7-dehydrocholesterol, low cholesterol, and multisystem developmental abnormalities. The biochemical hallmark is reduced 7-dehydrocholesterol reductase activity, making GO:0047598 a direct diagnostic and therapeutic target.
Ferroptosis and liver disease
7-DHC, the substrate of DHCR7, acts as an endogenous suppressor of ferroptosis, so inhibition of DHCR7 can protect cells from lipid peroxidation. In metabolic dysfunction-associated steatohepatitis, cholesterol overload in macrophages inhibits DHCR7, contributing to disease pathogenesis.
Viral infection
DHCR7 is a host dependency factor for enterovirus A71 (EV-A71); targeting 7-dehydrocholesterol reductase activity upregulates interferon responses and inhibits viral replication. Inhibition of DHCR7 also integrates cholesterol metabolism with IRF3 activation to eliminate infection.
Cancer
m6A-mediated induction of DHCR7 stimulates cholesterol synthesis and cAMP signaling, promoting bladder cancer metastasis. This positions 7-dehydrocholesterol reductase activity as a potential therapeutic target in oncology.
From 7-dehydrocholesterol reductase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of DHCR7 affect cholesterol synthesis and 7-DHC levels? | DHCR7 knockout cell lines (e.g., HepG2, HEK293) |
| Does a specific point mutation in DHCR7 alter enzyme activity? | Point-mutation knock-in models (e.g., patient-derived mutations) |
| Can wild-type DHCR7 rescue Smith-Lemli-Opitz syndrome phenotypes? | Knock-in of wild-type DHCR7 in mutant cells |
| Where is DHCR7 localized and how does it traffic? | Tagged knock-in of DHCR7 with fluorescent or affinity tags |
| Does DHCR7 overexpression promote cancer metastasis? | Overexpression of DHCR7 in bladder cancer cell lines |
| Does DHCR7 inhibition activate IRF3 and interferon? | Knockout or pharmacological inhibition in immune cells |
How to Study the 7-dehydrocholesterol reductase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Enzymatic assay with NADPH | 7-dehydrocholesterol reductase activity | Kinetic characterization of DHCR7 variants |
| LC-MS/MS sterol profiling | Cholesterol and 7-dehydrocholesterol levels | Diagnosis of Smith-Lemli-Opitz syndrome |
| RNA-seq | Transcriptional changes upon DHCR7 manipulation | Pathway analysis in cancer and infection |
| Proteomics | Protein expression and interactions | Identifying DHCR7-associated complexes |
| Lipid peroxidation assay | Ferroptosis sensitivity | Testing 7-DHC-mediated ferroptosis suppression |
| Immunofluorescence | Subcellular localization of DHCR7 | Endoplasmic reticulum targeting |
| CRISPR knockout screening | Genes required for cholesterol synthesis | Identifying synthetic lethal interactions |
| Metabolomics | Global metabolic shifts | MASH and cancer metabolism studies |
Measuring enzyme activity
7-dehydrocholesterol reductase activity can be measured by monitoring the conversion of 7-dehydrocholesterol to cholesterol using NADPH consumption or by quantifying sterol levels via mass spectrometry. These assays are essential for confirming loss-of-function or gain-of-function phenotypes in DHCR7 models.
Transcriptomic and proteomic profiling
RNA-seq and proteomics can reveal how DHCR7 manipulation affects cholesterol biosynthesis genes, interferon responses, and ferroptosis pathways. Such profiling helps identify downstream effectors of 7-dehydrocholesterol reductase activity.
Lipidomics and metabolomics
Lipidomic analysis quantifies 7-dehydrocholesterol, cholesterol, and related sterols to assess the impact of DHCR7 activity on cellular lipid composition. This is particularly useful in disease models such as Smith-Lemli-Opitz syndrome and MASH.
Imaging and subcellular localization
Fluorescence microscopy of tagged DHCR7 or sterol probes can visualize endoplasmic reticulum localization and cholesterol distribution. Imaging also helps assess ferroptosis and lipid peroxidation in live cells.
How CRISPR Can Be Used to Study GO:0047598 7-dehydrocholesterol reductase activity
Knockout
CRISPR knockout of DHCR7 eliminates 7-dehydrocholesterol reductase activity, causing 7-DHC accumulation and cholesterol depletion. This model is used to study ferroptosis, viral infection, and developmental defects.
Point Mutation
Point mutations identified in Smith-Lemli-Opitz syndrome patients can be introduced into DHCR7 via CRISPR to assess their impact on enzyme activity and stability. Such models help genotype-phenotype correlations.
Knock-in
Knock-in of tagged or wild-type DHCR7 allows rescue experiments and localization studies. This is valuable for confirming that specific mutations are causative and for testing therapeutic corrections.
Overexpression
CRISPR activation or cDNA overexpression of DHCR7 increases 7-dehydrocholesterol reductase activity, reducing 7-DHC and boosting cholesterol synthesis. Overexpression models are used to study cancer metastasis and antiviral responses.
How EDITGENE Supports 7-dehydrocholesterol reductase activity Research
Researchers studying 7-dehydrocholesterol reductase activity-related genes often need to determine whether a candidate gene is causally involved in cholesterol metabolism, ferroptosis, or disease phenotypes. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for 7-dehydrocholesterol reductase activity research.
Frequently Asked Questions About 7-dehydrocholesterol reductase activity
What is 7-dehydrocholesterol reductase activity?
It is the enzyme activity (GO:0047598) that converts 7-dehydrocholesterol to cholesterol using NADPH, the final step of cholesterol biosynthesis.
What gene encodes 7-dehydrocholesterol reductase?
The DHCR7 gene encodes the enzyme responsible for 7-dehydrocholesterol reductase activity.
What diseases are associated with 7-dehydrocholesterol reductase deficiency?
Smith-Lemli-Opitz syndrome is caused by DHCR7 mutations; the activity is also linked to ferroptosis, viral infection, and cancer.
How is 7-dehydrocholesterol reductase activity measured?
It can be measured by enzymatic assays monitoring NADPH consumption or by mass spectrometry quantification of cholesterol and 7-dehydrocholesterol.
What is the role of 7-dehydrocholesterol in ferroptosis?
7-DHC, the substrate of DHCR7, acts as an endogenous suppressor of ferroptosis, so inhibiting DHCR7 can protect cells from lipid peroxidation.
Can 7-dehydrocholesterol reductase be targeted for antiviral therapy?
Yes, inhibition of DHCR7 upregulates interferon responses and inhibits EV-A71 replication.
How does DHCR7 promote cancer metastasis?
m6A-mediated induction of DHCR7 stimulates cholesterol synthesis and cAMP signaling, promoting bladder cancer metastasis.
What are the synonyms for 7-dehydrocholesterol reductase activity?
Synonyms include 7-DHC reductase activity, cholesterol:NADP+ delta7-oxidoreductase activity, and sterol delta7-reductase activity.
Where is 7-dehydrocholesterol reductase located in the cell?
DHCR7 is an endoplasmic reticulum membrane protein.
What model systems are used to study 7-dehydrocholesterol reductase activity?
Knockout, point-mutation, knock-in, and overexpression cell models, as well as animal models, are used.
Conclusion
7-dehydrocholesterol reductase activity (GO:0047598) is a critical enzymatic function that completes cholesterol biosynthesis and controls the levels of the bioactive sterol 7-DHC. Its dysregulation underlies Smith-Lemli-Opitz syndrome and contributes to ferroptosis, viral infection, liver disease, and cancer metastasis. Continued research using precise CRISPR models will clarify its therapeutic potential and mechanistic links to human disease.
References
- 1. Freitas FP et al.. 2024. 7-Dehydrocholesterol is an endogenous suppressor of ferroptosis.. Nature 626(7998):401-410 PMID: 38297129
- 2. Xiao J et al.. 2020. Targeting 7-Dehydrocholesterol Reductase Integrates Cholesterol Metabolism and IRF3 Activation to Eliminate Infection.. Immunity 52(1):109-122.e6 PMID: 31882361
- 3. Yamada N et al.. 2024. Inhibition of 7-dehydrocholesterol reductase prevents hepatic ferroptosis under an active state of sterol synthesis.. Nat Commun 15(1):2195 PMID: 38472233
- 4. Zeng Y et al.. 2024. m6A-Mediated Induction of 7-Dehydrocholesterol Reductase Stimulates Cholesterol Synthesis and cAMP Signaling to Promote Bladder Cancer Metastasis.. Cancer Res 84(20):3402-3418 PMID: 39047230
- 5. Wang H et al.. 2023. Targeting 7-dehydrocholesterol reductase against EV-A71 replication by upregulating interferon response.. Antiviral Res 209:105497 PMID: 36528172
- 6. Xiao J et al.. 2025. Targeting 7-Dehydrocholesterol Reductase Integrates Cholesterol Metabolism and IRF3 Activation to Eliminate Infection.. Immunity 58(6):1614 PMID: 40280828
- 7. Li X et al.. 2024. Cholesterol overload in macrophages drives metabolic dysfunction-associated steatohepatitis via inhibiting 7-dehydrocholesterol reductase in mice.. J Transl Med 22(1):1085 PMID: 39614331
- 8. Kritzer A et al.. 2025. Smith-Lemli-Opitz syndrome: Clinical, biochemical, and genetic insights with emerging treatment opportunities.. Genet Med 27(7):101450 PMID: 40314187
