GO:0070814 hydrogen sulfide biosynthetic process: Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070814 hydrogen sulfide biosynthetic process describes the chemical reactions and pathways that produce hydrogen sulfide (H2S).
• H2S is a gasotransmitter with roles in redox metabolism, signaling, and physiology.
• Key enzymes include CBS, CTH, MPST, and 3-MST, which generate H2S from cysteine and other sulfur-containing substrates.
• H2S levels are regulated by synthesis and oxidation, with sulfide quinone oxidoreductase (SQOR) playing a central role in its catabolism.
• Dysregulated H2S biosynthesis is implicated in ischemia-reperfusion injury, retinal diseases, and aging-related oxidative stress.
• CRISPR-based models (knockout, knock-in, overexpression) enable causal studies of H2S biosynthetic genes in disease and physiology.
Description
Hydrogen sulfide (H2S) is a gaseous signaling molecule that is endogenously produced in mammalian tissues. The Gene Ontology (GO) term GO:0070814, hydrogen sulfide biosynthetic process, refers to the chemical reactions and pathways that result in the formation of H2S. This process is essential for maintaining cellular redox balance and for modulating a wide range of physiological functions, including vasodilation, neurotransmission, and cytoprotection. Researchers study this term to understand how H2S is generated, how its production is regulated, and how it contributes to health and disease. The biosynthetic process involves multiple enzymes, primarily cystathionine beta-synthase (CBS), cystathionine gamma-lyase (CTH), 3-mercaptopyruvate sulfurtransferase (MPST), and cysteine aminotransferase (CAT), which collectively convert cysteine and related sulfur-containing amino acids into H2S. The balance between H2S synthesis and its oxidation by enzymes such as sulfide quinone oxidoreductase (SQOR) determines steady-state H2S levels, which are critical for its signaling actions. Consequently, GO:0070814 is a focal point for research in redox biology, cardiovascular physiology, and neurobiology.
hydrogen sulfide biosynthetic process At A Glance
| GO ID | GO:0070814 |
|---|---|
| GO term | hydrogen sulfide biosynthetic process |
| Ontology | biological_process |
| Synonym | hydrogen sulfide anabolism; hydrogen sulfide biosynthesis; hydrogen sulfide formation; hydrogen sulfide synthesis; hydrogen sulphide biosynthesis; hydrogen sulphide biosynthetic process |
| Major function | Production of hydrogen sulfide (H2S) from sulfur-containing substrates |
| Key enzymes | CBS, CTH, MPST, CAT, and others |
| Substrates | Cysteine, homocysteine, 3-mercaptopyruvate, and related sulfur compounds |
| Regulation | Transcriptional, post-translational, and substrate availability |
| Related process | H2S oxidation by SQOR and other enzymes |
What Is GO:0070814?
The hydrogen sulfide biosynthetic process (GO:0070814) encompasses the chemical reactions and pathways that lead to the formation of hydrogen sulfide (H2S). This includes enzymatic and non-enzymatic steps that generate H2S from substrates such as cysteine, homocysteine, and 3-mercaptopyruvate. The process is a biological process and is distinct from H2S catabolism or signaling, although it is tightly linked to those processes.
Why Is hydrogen sulfide biosynthetic process Important in Cell Biology?
Hydrogen sulfide is now recognized as a third gasotransmitter alongside nitric oxide and carbon monoxide, with critical roles in cardiovascular, nervous, and immune systems. The biosynthetic process GO:0070814 is therefore central to understanding how cells produce this signaling molecule. Dysregulation of H2S synthesis has been linked to numerous pathological conditions, including ischemia-reperfusion injury, neurodegenerative diseases, and cancer. Moreover, H2S biosynthesis is a target for therapeutic intervention, as modulating its levels can protect against oxidative stress and inflammation. Thus, studying GO:0070814 provides insights into fundamental biology and potential treatments for human diseases.
• H2S is a gasotransmitter involved in vasodilation and cardioprotection.
• H2S biosynthesis modulates oxidative stress and aging processes.
• Dysregulated H2S production contributes to ischemia-reperfusion injury.
• H2S plays a role in retinal physiology and disease.
• Enzymes of H2S biosynthesis are potential drug targets.
• H2S biosynthesis is linked to neurological function and neurodegeneration.
• H2S influences inflammation and immune responses.
• H2S biosynthesis interacts with redox metabolism via SQOR.
• Genetic variants in H2S-producing enzymes affect disease susceptibility.
• CRISPR models enable precise study of H2S biosynthetic genes.
What Happens During hydrogen sulfide biosynthetic process?
Transsulfuration pathway
In simple terms: This is the main route where cells convert homocysteine to cysteine and then release hydrogen sulfide.
The transsulfuration pathway involves two key enzymes: cystathionine beta-synthase (CBS) and cystathionine gamma-lyase (CTH). CBS condenses homocysteine with serine to form cystathionine, which is then cleaved by CTH to produce cysteine and alpha-ketobutyrate. Both enzymes can also catalyze reactions that directly generate H2S from cysteine or homocysteine. This pathway is particularly active in the liver, kidney, and nervous system.
3-Mercaptopyruvate pathway
In simple terms: In this route, cysteine is first converted to 3-mercaptopyruvate, which then releases hydrogen sulfide.
Cysteine aminotransferase (CAT) transfers an amino group from cysteine to alpha-ketoglutarate, yielding 3-mercaptopyruvate. This intermediate is then acted upon by 3-mercaptopyruvate sulfurtransferase (MPST), which produces H2S and pyruvate. This pathway is prominent in the brain and vascular endothelium.
Non-enzymatic and alternative routes
In simple terms: Some hydrogen sulfide can be produced without enzymes, or through other lesser-known reactions.
In addition to enzymatic pathways, H2S can be generated non-enzymatically from persulfides or by reduction of sulfur-containing compounds. However, the enzymatic routes are the primary contributors to regulated H2S biosynthesis. Alternative enzymes such as cysteine lyase and mercaptopyruvate sulfurtransferase also participate.
Regulation of H2S biosynthesis
In simple terms: The production of hydrogen sulfide is controlled by changing enzyme levels or activity.
H2S biosynthesis is regulated at multiple levels. Transcription of CBS, CTH, and MPST can be induced by factors such as oxidative stress or inflammatory cytokines. Post-translational modifications, including phosphorylation and S-sulfhydration, modulate enzyme activity. Substrate availability, particularly cysteine and homocysteine, also influences H2S production. Additionally, H2S levels are balanced by its oxidation via sulfide quinone oxidoreductase (SQOR), which prevents toxic accumulation.
Key Genes Involved in GO:0070814 hydrogen sulfide biosynthetic process
The following genes encode enzymes and proteins directly involved in the hydrogen sulfide biosynthetic process.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CBS | Condenses homocysteine and serine to cystathionine; also produces H2S | Mutations cause homocystinuria; target in cardiovascular and neurobiology |
| CTH | Cleaves cystathionine to cysteine and alpha-ketobutyrate; generates H2S | Linked to liver disease and cancer; knockout models available |
| MPST | Produces H2S from 3-mercaptopyruvate | Important in brain and vascular H2S production |
| CAT | Transaminates cysteine to 3-mercaptopyruvate | Regulates substrate supply for MPST |
| SQOR | Oxidizes H2S to thiosulfate and sulfite | Controls H2S catabolism; deficiency causes sulfide toxicity |
| GOT1 | Aspartate aminotransferase; may contribute to cysteine metabolism | Indirect role in H2S production |
| GOT2 | Mitochondrial aspartate aminotransferase | Involved in sulfur amino acid metabolism |
| MOCOS | Molybdenum cofactor sulfurase; affects sulfur metabolism | Potential regulator of H2S levels |
| SUOX | Sulfite oxidase; involved in sulfur oxidation | Indirectly affects H2S catabolism |
| TST | Thiosulfate sulfurtransferase; produces H2S from thiosulfate | Alternative H2S source in mitochondria |
| ETHE1 | Persulfide dioxygenase; involved in H2S oxidation | Mutations cause ethylmalonic encephalopathy |
| SLC7A11 | Cystine/glutamate antiporter; supplies cysteine for H2S synthesis | Links H2S production to oxidative stress |
| GCLC | Glutamate-cysteine ligase; affects cysteine availability | Modulates H2S biosynthesis indirectly |
| GCLM | Glutamate-cysteine ligase modifier subunit | Regulates glutathione and cysteine pools |
| NFS1 | Cysteine desulfurase; provides sulfur for H2S and iron-sulfur clusters | Mitochondrial H2S production |
| SLC25A39 | Mitochondrial transporter; may affect sulfur metabolism | Potential role in H2S biosynthesis |
| SLC25A40 | Mitochondrial carrier; involved in sulfur amino acid transport | Candidate regulator |
| SLC25A42 | Mitochondrial carrier; CoA transport | Indirect link to H2S metabolism |
How Is hydrogen sulfide biosynthetic process Regulated?
The hydrogen sulfide biosynthetic process is regulated at transcriptional, post-transcriptional, and post-translational levels. Expression of CBS, CTH, and MPST can be induced by oxidative stress, inflammatory cytokines, and growth factors. Post-translational modifications such as phosphorylation and S-sulfhydration modulate enzyme activity. Substrate availability, particularly cysteine and homocysteine, is a key determinant of H2S production. Additionally, H2S levels are tightly controlled by its oxidation via SQOR, which is itself regulated by the redox state and by H2S-dependent activation. This balance ensures that H2S acts as a signaling molecule without reaching toxic concentrations.
hydrogen sulfide biosynthetic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CBS | Homocystinuria, cardiovascular disease | Knockout mouse, patient-derived iPSCs |
| CTH | Liver fibrosis, cancer | Liver-specific knockout, overexpression |
| MPST | Neurodegeneration, hypertension | Neuron-specific knockout, knock-in |
| SQOR | Sulfide toxicity, Leigh syndrome | Knockout cells, point mutations |
| SLC7A11 | Cancer, oxidative stress | CRISPR knockout, overexpression |
Ischemia-reperfusion injury
H2S biosynthesis plays a dual role in ischemia-reperfusion injury. While moderate H2S production can protect against oxidative damage, excessive or dysregulated H2S synthesis may exacerbate injury. Studies have shown that modulating H2S levels through CBS and CTH activity can influence outcomes in cardiac and cerebral ischemia-reperfusion models. The therapeutic potential of H2S donors and inhibitors is an active area of research.
Retinal diseases
In the retina, H2S biosynthesis is involved in neuroprotection and vascular function. Dysregulation of H2S-producing enzymes has been implicated in diabetic retinopathy and glaucoma. Targeting H2S biosynthesis may offer therapeutic strategies for retinal degenerative diseases.
Aging and oxidative stress
H2S biosynthesis declines with age, contributing to increased oxidative stress and age-related pathologies. Conversely, enhancing H2S production has been shown to extend lifespan in animal models. The interplay between H2S and aging is mediated by its antioxidant and signaling properties.
Cancer
H2S biosynthesis is often upregulated in cancer cells, where it supports proliferation and survival. CBS and CTH are overexpressed in several cancers, making them potential targets for anticancer therapy. However, the role of H2S in cancer is context-dependent, with both pro- and anti-tumor effects reported.
From hydrogen sulfide biosynthetic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does CBS loss affect H2S levels and cardiovascular function? | CBS knockout mouse or CRISPR KO cells |
| How does a point mutation in CTH alter enzyme activity? | CRISPR point mutation knock-in |
| Can overexpression of MPST protect neurons? | MPST overexpression lentivirus |
| What is the role of SQOR in H2S catabolism? | SQOR knockout and tagged knock-in |
| How does H2S biosynthesis affect cancer cell proliferation? | CRISPR library screening for H2S genes |
| Does S-sulfhydration regulate CBS activity? | Tagged knock-in for proteomics |
How to Study the hydrogen sulfide biosynthetic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Colorimetric H2S assay | Total H2S concentration | Cell lysates and tissues |
| Fluorescent H2S probes | Real-time H2S levels | Live-cell imaging |
| Enzyme activity assay | CBS/CTH/MPST activity | Recombinant proteins or lysates |
| RNA-seq | mRNA expression of H2S enzymes | Transcriptional profiling |
| Proteomics | Protein abundance and modifications | S-sulfhydration detection |
| CRISPR screening | Gene essentiality and function | Identify novel H2S regulators |
| Metabolomics | Sulfur metabolites | Pathway flux analysis |
Measuring H2S production
H2S levels can be measured using colorimetric assays, fluorescent probes, or gas chromatography. These methods allow quantification of H2S in cells and tissues, providing direct readouts of biosynthetic activity.
Enzyme activity assays
Enzymatic activities of CBS, CTH, and MPST can be assessed using substrate-specific assays that monitor the formation of H2S or its products. These assays are essential for characterizing the effects of genetic modifications.
Gene expression analysis
RNA-seq and qPCR can quantify mRNA levels of H2S-producing enzymes under different conditions. This helps identify transcriptional regulation of the biosynthetic process.
Proteomics and post-translational modifications
Mass spectrometry-based proteomics can detect S-sulfhydration and other modifications on H2S enzymes, revealing regulatory mechanisms. Tagged knock-in models facilitate enrichment of these proteins.
How CRISPR Can Be Used to Study GO:0070814 hydrogen sulfide biosynthetic process
Knockout
CRISPR knockout of CBS, CTH, or MPST eliminates H2S production, allowing researchers to study the consequences of loss of function in cells and animal models. Knockout models are essential for determining the causal role of H2S in physiology and disease.
Point Mutation
Introducing specific point mutations in H2S-producing enzymes can mimic human genetic variants or alter catalytic activity. This approach helps dissect the contribution of individual amino acids to enzyme function and H2S production.
Knock-in
Knock-in of tags (e.g., FLAG, HA) or reporter genes allows for tracking endogenous H2S enzymes, studying their localization, and identifying interaction partners. Tagged knock-in models are valuable for proteomic and imaging studies.
Overexpression
Overexpression of CBS, CTH, or MPST via CRISPR activation or lentiviral vectors increases H2S production, enabling gain-of-function studies. This is useful for testing protective effects of H2S in disease models.
How EDITGENE Supports hydrogen sulfide biosynthetic process Research
Researchers studying hydrogen sulfide biosynthetic process-related genes often need to determine whether a candidate gene is causally involved in H2S production, signaling, or disease. EDITGENE provides a comprehensive suite of CRISPR services to enable such investigations, from gene knockout to precise point mutations and overexpression.
Contact EDITGENE today to design your custom CRISPR model for hydrogen sulfide biosynthetic process research.
Frequently Asked Questions About hydrogen sulfide biosynthetic process
What is hydrogen sulfide biosynthetic process?
It is the biological process (GO:0070814) by which cells produce hydrogen sulfide (H2S) from substrates like cysteine.
What genes are involved in hydrogen sulfide biosynthetic process?
Key genes include CBS, CTH, MPST, and CAT, which encode enzymes that generate H2S.
How is hydrogen sulfide produced in cells?
H2S is produced mainly through the transsulfuration pathway and the 3-mercaptopyruvate pathway, involving enzymes like CBS, CTH, and MPST.
What is the role of H2S in the body?
H2S acts as a gasotransmitter, regulating vasodilation, neurotransmission, and antioxidant responses.
Which diseases are linked to H2S biosynthesis?
Dysregulated H2S production is implicated in ischemia-reperfusion injury, retinal diseases, cancer, and aging.
How can I study H2S biosynthesis using CRISPR?
CRISPR knockout, knock-in, and overexpression of H2S enzymes allow causal studies of H2S function in cells and animal models.
What is the function of SQOR in H2S metabolism?
SQOR oxidizes H2S, controlling its levels and preventing toxicity.
Can H2S levels be measured in cells?
Yes, using colorimetric assays, fluorescent probes, or gas chromatography.
What are the main enzymes for H2S synthesis?
CBS, CTH, MPST, and CAT are the primary enzymes.
Is H2S production regulated?
Yes, it is regulated transcriptionally, post-translationally, and by substrate availability.
Conclusion
The hydrogen sulfide biosynthetic process (GO:0070814) is a fundamental biological pathway with wide-ranging implications for health and disease. Understanding its regulation and function through CRISPR-based models will continue to reveal new therapeutic opportunities. EDITGENE offers the tools and expertise to accelerate this research.
References
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- 3. Bian JS et al.. 2016. Hydrogen Sulfide: Biogenesis, Physiology, and Pathology.. Oxid Med Cell Longev 2016:6549625 PMID: 27148431
- 4. Yang G et al.. 2015. Hydrogen Sulfide Signaling in Oxidative Stress and Aging Development.. Oxid Med Cell Longev 2015:357824 PMID: 26075033
- 5. Roman JV et al.. 2025. Hydrogen sulfide-dependent activation of human sulfide quinone oxidoreductase.. J Biol Chem 301(10):110681 PMID: 40912653
- 6. Sun X et al.. 2024. Therapeutic Potential of Hydrogen Sulfide in Ischemia and Reperfusion Injury.. Biomolecules 14(7) PMID: 39062455
- 7. Cornwell A et al.. 2023. The role of hydrogen sulfide in the retina.. Exp Eye Res 234:109568 PMID: 37460081
- 8. Landry AP et al.. 2021. Hydrogen Sulfide Oxidation by Sulfide Quinone Oxidoreductase.. Chembiochem 22(6):949-960 PMID: 33080111
