GO:0008074 guanylate cyclase complex, soluble: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008074 (guanylate cyclase complex, soluble) is a cellular_component term describing a non-membrane-bound complex that possesses guanylate cyclase activity.
• The soluble guanylate cyclase (sGC) complex is a heterodimer typically composed of alpha and beta subunits, and it catalyzes the conversion of GTP to cGMP.
• sGC is a key receptor for nitric oxide (NO) and is central to NO-cGMP signaling in the cardiovascular, pulmonary, and renal systems.
• Pharmacological stimulators and activators of sGC, such as riociguat and vericiguat, are used or investigated in pulmonary hypertension, heart failure, and resistant hypertension.
• Dysregulation of sGC signaling contributes to pulmonary arterial hypertension, diabetic kidney disease, and thrombotic disorders.
• Research on GO:0008074 uses knockout, point-mutation, knock-in, and overexpression models, combined with biochemical assays, imaging, and omics methods.
Description
The Gene Ontology (GO) term GO:0008074, guanylate cyclase complex, soluble, defines a cellular component that is not bound to a membrane and possesses guanylate cyclase activity. This complex is best known as soluble guanylate cyclase (sGC), the primary intracellular receptor for nitric oxide (NO). sGC catalyzes the conversion of guanosine triphosphate (GTP) to cyclic guanosine monophosphate (cGMP), a second messenger that regulates vascular tone, platelet function, and cardiac and renal physiology. Because sGC is a central node in NO-cGMP signaling, its dysfunction is implicated in pulmonary arterial hypertension, heart failure, resistant hypertension, and diabetic kidney disease. Understanding the structure, assembly, and regulation of the soluble guanylate cyclase complex is therefore critical for both basic biology and therapeutic development. This article provides a research-grade overview of GO:0008074, covering its definition, composition, molecular mechanism, associated genes, disease relevance, and experimental methods, including CRISPR-based models.
guanylate cyclase complex, soluble At A Glance
| GO ID | GO:0008074 |
|---|---|
| GO term | guanylate cyclase complex, soluble |
| Ontology | cellular_component |
| Synonym | None listed in QuickGO |
| Major function | Catalyzes the conversion of GTP to cGMP; acts as the primary receptor for nitric oxide (NO) |
| Complex type | Heterodimeric protein complex, typically composed of alpha and beta subunits |
| Subcellular location | Cytosol; not bound to a membrane |
| Key activators | Nitric oxide (NO), sGC stimulators (e.g., riociguat, vericiguat) |
| Associated diseases | Pulmonary arterial hypertension, heart failure, resistant hypertension, diabetic kidney disease |
What Is GO:0008074?
GO:0008074 (guanylate cyclase complex, soluble) is a cellular_component term that describes a protein complex with guanylate cyclase activity that is not attached to a membrane. In practice, this term refers to the soluble guanylate cyclase (sGC) heterodimer, which is a cytosolic enzyme activated by nitric oxide (NO) and catalyzes the synthesis of cGMP from GTP. The complex is distinct from membrane-bound guanylate cyclases, which are receptor enzymes with extracellular ligand-binding domains.
Why Is guanylate cyclase complex, soluble Important in Cell Biology?
The soluble guanylate cyclase complex (GO:0008074) is a central mediator of nitric oxide (NO) signaling, which regulates vascular smooth muscle relaxation, platelet aggregation, and cardiac and renal function. Dysregulation of this complex is directly linked to major human diseases, including pulmonary arterial hypertension, heart failure, resistant hypertension, and diabetic kidney disease. Pharmacological agents that stimulate or activate sGC, such as riociguat and vericiguat, have demonstrated clinical benefit, underscoring the therapeutic importance of this complex. Consequently, studying GO:0008074 is essential for understanding cardiovascular and renal pathophysiology and for developing novel therapeutics.
• sGC is the primary receptor for nitric oxide (NO) and mediates vasodilation and inhibition of platelet aggregation.
• Mutations or dysregulation of sGC subunits are associated with pulmonary arterial hypertension and heart failure.
• sGC stimulators like riociguat improve exercise capacity in pulmonary hypertension patients.
• Vericiguat, an sGC stimulator, inhibits platelet activation and thrombosis, suggesting a role in thrombotic disorders.
• sGC signaling is impaired in diabetic kidney disease, making it a therapeutic target.
• Resistant hypertension often involves defective NO-sGC-cGMP signaling, and sGC modulators are emerging treatment options.
• The complex is a model system for studying heterodimeric enzyme assembly and allosteric regulation.
• sGC activity can be regulated by endogenous molecules such as carnosine, highlighting additional layers of control.
• Knockout and transgenic models of sGC subunits are valuable for dissecting its physiological roles.
• sGC is a target for drug discovery, with stimulators and activators in clinical use or trials.
Structure and Composition of guanylate cyclase complex, soluble
Heterodimeric Core: Alpha and Beta Subunits
In simple terms: The soluble guanylate cyclase complex is made of two different protein chains, called alpha and beta, that work together.
The soluble guanylate cyclase (sGC) complex is a heterodimer typically composed of one alpha subunit and one beta subunit. Each subunit contains a heme-binding domain, a dimerization domain, and a catalytic domain. The beta subunit harbors the heme prosthetic group that binds nitric oxide (NO), while the alpha subunit contributes to catalysis and regulation. The heterodimeric assembly is essential for enzymatic activity and NO responsiveness.
Heme Prosthetic Group and NO Binding
In simple terms: A heme molecule sits in the beta subunit and acts like a switch that turns the enzyme on when nitric oxide binds.
The beta subunit of sGC contains a prosthetic heme group coordinated by histidine residues. Binding of nitric oxide (NO) to this heme triggers a conformational change that activates the catalytic domain, leading to a dramatic increase in cGMP production. This heme-dependent activation is a hallmark of the soluble guanylate cyclase complex and distinguishes it from membrane-bound guanylate cyclases.
Catalytic Domain and GTP Conversion
In simple terms: The catalytic part of the complex grabs GTP and turns it into cGMP, a signaling molecule.
The catalytic domain of sGC is formed by the juxtaposition of the alpha and beta subunits. Upon activation, it catalyzes the cyclization of guanosine triphosphate (GTP) to cyclic guanosine monophosphate (cGMP) and pyrophosphate. This reaction is dependent on magnesium or manganese ions and is allosterically regulated by NO binding to the heme.
Assembly and Subcellular Localization
In simple terms: The complex is built inside the cell and stays in the cytosol, not attached to any membrane.
The soluble guanylate cyclase complex is assembled in the cytosol and is not bound to a membrane, as defined by GO:0008074. The alpha and beta subunits are co-translationally folded and assemble into a functional heterodimer. This cytosolic localization allows sGC to rapidly respond to diffusible NO and to modulate nearby targets such as protein kinase G (PKG).
Key Genes Involved in GO:0008074 guanylate cyclase complex, soluble
The following genes encode the subunits and regulatory proteins of the soluble guanylate cyclase complex (GO:0008074) and are commonly studied in cardiovascular and renal research.
| Gene | Major Role | Research Relevance |
|---|---|---|
| GUCY1A1 | Encodes the alpha-1 subunit of soluble guanylate cyclase | Mutations linked to pulmonary hypertension and cardiovascular disease |
| GUCY1A2 | Encodes the alpha-2 subunit | Expressed in brain and vascular tissues; involved in NO signaling |
| GUCY1A3 | Encodes the alpha-3 subunit | Associated with hypertension and platelet function |
| GUCY1B1 | Encodes the beta-1 subunit containing the heme group | Essential for NO binding and catalytic activity; target for sGC stimulators |
| GUCY1B2 | Encodes the beta-2 subunit | Less characterized; may form alternative heterodimers |
| GUCY1B3 | Encodes the beta-3 subunit | Expressed in specific tissues; potential role in renal function |
| PRKG1 | Encodes cGMP-dependent protein kinase G | Downstream effector of sGC; mediates vasodilation and platelet inhibition |
| PDE5A | Encodes phosphodiesterase 5 | Degrades cGMP; regulates sGC pathway activity |
| NPR1 | Encodes natriuretic peptide receptor 1 | Membrane guanylate cyclase; contrasts with soluble sGC |
| NPR2 | Encodes natriuretic peptide receptor 2 | Membrane guanylate cyclase; involved in bone growth |
| HSP90AA1 | Heat shock protein 90 | Chaperone for sGC assembly and stability |
| CCT | Chaperonin containing TCP-1 | Assists in folding of sGC subunits |
| NOS3 | Endothelial nitric oxide synthase | Produces NO that activates sGC |
| NOS1 | Neuronal nitric oxide synthase | Produces NO in neurons; activates sGC |
| NOS2 | Inducible nitric oxide synthase | Produces NO during inflammation; activates sGC |
| ALDH2 | Aldehyde dehydrogenase 2 | May modulate NO bioavailability and sGC activity |
| CARN | Carnosine | Endogenous regulator of sGC activity |
How Is guanylate cyclase complex, soluble Regulated?
The activity of the soluble guanylate cyclase complex (GO:0008074) is tightly regulated at multiple levels. Nitric oxide (NO) binding to the heme group of the beta subunit is the primary activator, inducing a conformational change that increases catalytic activity by several hundred-fold. Endogenous molecules such as carnosine can also regulate sGC activity, potentially by interacting with the heme or catalytic site. Additionally, sGC stimulators (e.g., riociguat, vericiguat) enhance the enzyme's sensitivity to NO or activate it independently of NO. Phosphodiesterases, particularly PDE5A, degrade cGMP and thus attenuate the pathway. Protein-protein interactions, including with HSP90, influence sGC stability and assembly. Finally, oxidative stress can oxidize the heme, leading to sGC desensitization, a mechanism implicated in cardiovascular disease.
guanylate cyclase complex, soluble and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| GUCY1A1 | Pulmonary arterial hypertension | Knockout mouse; point-mutation knock-in of patient variants |
| GUCY1B1 | Heart failure, hypertension | Conditional knockout; overexpression of wild-type or mutant |
| GUCY1A3 | Resistant hypertension, platelet dysfunction | Platelet-specific knockout; knock-in of gain-of-function variants |
| PDE5A | Erectile dysfunction, pulmonary hypertension | Overexpression; CRISPR knockout to assess cGMP levels |
| NOS3 | Endothelial dysfunction, diabetic kidney disease | Endothelial-specific knockout; knock-in of polymorphic variants |
Pulmonary Arterial Hypertension
Pulmonary arterial hypertension (PAH) is characterized by impaired NO-sGC-cGMP signaling, leading to vasoconstriction and vascular remodeling. Reduced sGC activity or expression contributes to disease pathogenesis. Riociguat, an sGC stimulator, is approved for PAH and improves exercise capacity in patients. Thus, the soluble guanylate cyclase complex (GO:0008074) is a key therapeutic target in PAH.
Heart Failure and Resistant Hypertension
Defective NO-sGC-cGMP signaling is implicated in heart failure and resistant hypertension. Vericiguat, an sGC stimulator, has been investigated for heart failure and inhibits platelet activation, suggesting additional benefits in thrombotic complications. In resistant hypertension, sGC modulators may offer an alternative when standard therapies fail.
Diabetic Kidney Disease
Diabetic kidney disease is associated with endothelial dysfunction and impaired NO bioavailability, leading to reduced sGC activity. Targeting the sGC pathway with stimulators may protect renal function. Therefore, GO:0008074 is relevant to the pathophysiology and treatment of diabetic kidney disease.
Thrombosis and Platelet Function
The sGC-cGMP pathway inhibits platelet activation and aggregation. Vericiguat, an sGC stimulator, has been shown to inhibit platelet activation and thrombosis in experimental models. This highlights the role of GO:0008074 in thrombotic disorders and the potential of sGC modulators as antiplatelet agents.
From guanylate cyclase complex, soluble-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of sGC alpha-1 subunit impair NO-induced vasodilation? | GUCY1A1 knockout mouse or CRISPR knockout in vascular smooth muscle cells |
| How do patient-derived mutations in GUCY1B1 affect enzyme activity? | Point-mutation knock-in via CRISPR in cell lines or mice |
| Can overexpression of sGC subunits enhance cGMP signaling? | Overexpression of GUCY1A1/GUCY1B1 using lentiviral vectors |
| What is the role of the heme-binding histidine in sGC activation? | Point mutation (e.g., H105F) knock-in in GUCY1B1 |
| How does sGC stimulation affect platelet aggregation? | Platelet-specific knockout or knock-in of GUCY1A3 in mice |
| Can tagged sGC be used to study complex assembly? | Knock-in of FLAG- or GFP-tagged GUCY1B1 for imaging and proteomics |
How to Study the guanylate cyclase complex, soluble Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Guanylate cyclase activity assay | Conversion of GTP to cGMP | Assessing sGC function and drug effects |
| cGMP ELISA | Intracellular cGMP levels | Monitoring pathway activation in cells |
| Immunoprecipitation-Western blot | Protein-protein interactions and subunit assembly | Studying sGC complex composition |
| Fluorescence microscopy | Subcellular localization of tagged sGC | Confirming cytosolic localization |
| RNA-seq | Expression of GUCY1A1, GUCY1B1, and related genes | Transcriptomic profiling in disease models |
| Proteomics (IP-MS) | Interacting proteins and post-translational modifications | Identifying novel sGC regulators |
| CRISPR knockout screening | Genes affecting cGMP levels or sGC function | Discovery of pathway modifiers |
| Platelet aggregation assay | Platelet activation and thrombosis | Evaluating sGC stimulators |
Biochemical Assays for Guanylate Cyclase Activity
Enzymatic activity of the soluble guanylate cyclase complex can be measured by incubating cell lysates or purified protein with GTP and quantifying cGMP production using radioimmunoassay or ELISA. These assays are used to assess the effects of NO, stimulators, or mutations on sGC function.
Imaging and Subcellular Localization
Fluorescence microscopy with GFP- or FLAG-tagged sGC subunits allows visualization of complex assembly and localization in live cells. This is particularly useful for confirming the cytosolic, non-membrane-bound nature of GO:0008074.
Omics Approaches: Transcriptomics and Proteomics
RNA-seq can quantify expression of GUCY1A1, GUCY1B1, and related genes under different conditions. Proteomics, including immunoprecipitation-mass spectrometry, can identify interacting partners and post-translational modifications of the sGC complex.
CRISPR Screening for Modifiers of sGC Signaling
Genome-wide CRISPR knockout or activation screens can identify genes that regulate sGC expression or cGMP levels. Such screens have been used to uncover novel regulators of the NO-sGC-cGMP pathway in cardiovascular and renal cells.
How CRISPR Can Be Used to Study GO:0008074 guanylate cyclase complex, soluble
Knockout
CRISPR-Cas9 knockout of GUCY1A1 or GUCY1B1 can abolish sGC activity, providing a clean background to study its role in NO signaling. Knockout models are used to assess the contribution of GO:0008074 to vascular tone, platelet function, and renal physiology.
Point Mutation
Point mutations in the heme-binding domain of GUCY1B1 (e.g., histidine to phenylalanine) can be introduced via CRISPR to dissect the mechanism of NO activation. Such models help determine how specific residues affect enzyme activity and drug responsiveness.
Knock-in
Knock-in of patient-derived mutations in GUCY1A1 or GUCY1B1 using CRISPR allows study of disease-associated variants in isogenic cell lines or mice. Tagged knock-in (e.g., GFP or FLAG) enables imaging and proteomic analysis of the sGC complex.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of GUCY1A1 and GUCY1B1 can increase sGC levels and cGMP signaling. Overexpression models are useful for testing whether enhanced sGC activity protects against cardiovascular or renal injury.
How EDITGENE Supports guanylate cyclase complex, soluble Research
Researchers studying guanylate cyclase complex, soluble-related genes often need to determine whether a candidate gene is causally involved in sGC function, cGMP signaling, or disease phenotypes. EDITGENE provides a comprehensive suite of CRISPR services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for guanylate cyclase complex, soluble research.
Related Products
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| GUCY1A2 Knockout HEK293 Cell Line | EDJ-KQ1853 | Human | 2977 | Details Get a Quote |
| GUCY1A1 Knockout HEK293 Cell Line | EDJ-KQ1854 | Human | 2982 | Details Get a Quote |
| GUCY1B1 Knockout HEK293 Cell Line | EDJ-KQ1855 | Human | 2983 | Details Get a Quote |
| GUCY1A2 Knockout HeLa Cell Line | EDJ-KQ53456 | Human | 2977 | Details Get a Quote |
| GUCY1A1 Knockout HeLa Cell Line | EDJ-KQ53460 | Human | 2982 | Details Get a Quote |
| GUCY1B1 Knockout HeLa Cell Line | EDJ-KQ53461 | Human | 2983 | Details Get a Quote |
| GUCY1A2 Knockout A-549 Cell Line | EDJ-KQ61929 | Human | 2977 | Details Get a Quote |
| GUCY1A1 Knockout A-549 Cell Line | EDJ-KQ61932 | Human | 2982 | Details Get a Quote |
| GUCY1B1 Knockout A-549 Cell Line | EDJ-KQ61933 | Human | 2983 | Details Get a Quote |
| GUCY1A2 Knockout HCT 116 Cell Line | EDJ-KQ70410 | Human | 2977 | Details Get a Quote |
| GUCY1A1 Knockout HCT 116 Cell Line | EDJ-KQ70413 | Human | 2982 | Details Get a Quote |
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Frequently Asked Questions About guanylate cyclase complex, soluble
What is GO:0008074?
GO:0008074 is the Gene Ontology term for guanylate cyclase complex, soluble, a non-membrane-bound protein complex that possesses guanylate cyclase activity.
What is the soluble guanylate cyclase complex made of?
It is typically a heterodimer of alpha and beta subunits, with the beta subunit containing a heme group that binds nitric oxide.
What genes are involved in guanylate cyclase complex, soluble?
Key genes include GUCY1A1, GUCY1A2, GUCY1A3, GUCY1B1, GUCY1B2, and GUCY1B3, which encode the subunits of soluble guanylate cyclase.
What does soluble guanylate cyclase do?
It catalyzes the conversion of GTP to cGMP, a second messenger that regulates vascular tone, platelet function, and cardiac and renal physiology.
How is soluble guanylate cyclase activated?
It is activated by nitric oxide (NO) binding to its heme group, and also by pharmacological stimulators such as riociguat and vericiguat.
What diseases are associated with soluble guanylate cyclase dysfunction?
Dysfunction is linked to pulmonary arterial hypertension, heart failure, resistant hypertension, diabetic kidney disease, and thrombosis.
What are sGC stimulators?
sGC stimulators are drugs that enhance the activity of soluble guanylate cyclase, either by increasing its sensitivity to NO or by activating it directly.
How can I study GO:0008074 in the lab?
Common methods include guanylate cyclase activity assays, cGMP ELISA, fluorescence microscopy, RNA-seq, proteomics, and CRISPR screens.
What CRISPR models are available for sGC research?
Knockout, point mutation, knock-in, tagged knock-in, and overexpression models can be generated for sGC subunit genes using CRISPR-Cas9.
Why is the soluble guanylate cyclase complex important for drug discovery?
It is a validated therapeutic target, with approved drugs like riociguat and vericiguat, and ongoing development for cardiovascular and renal diseases.
Conclusion
The soluble guanylate cyclase complex (GO:0008074) is a central component of nitric oxide signaling, with critical roles in cardiovascular, pulmonary, and renal physiology. Its dysfunction contributes to major human diseases, and pharmacological modulation has proven clinically beneficial. Continued research using advanced CRISPR models and omics approaches will further elucidate its regulation and therapeutic potential.
References
- 1. Thenappan T et al.. 2018. Pulmonary arterial hypertension: pathogenesis and clinical management.. BMJ 360:j5492 PMID: 29540357
- 2. Yi TW et al.. 2026. Next-generation therapeutics for diabetic kidney disease.. Nat Rev Nephrol 22(5):318-332 PMID: 41526484
- 3. Flack JM et al.. 2024. Resistant Hypertension: Disease Burden and Emerging Treatment Options.. Curr Hypertens Rep 26(5):183-199 PMID: 38363454
- 4. Zhou W et al.. 2025. The soluble guanylate cyclase (sGC) stimulator vericiguat inhibits platelet activation and thrombosis.. Eur J Pharmacol 999:177670 PMID: 40287044
- 5. De Feo D et al.. 2025. Influence of Soluble Guanylate Cyclase on Cardiac, Vascular, and Renal Structure and Function: A Physiopathological Insight.. Int J Mol Sci 26(10) PMID: 40429695
- 6. Severina IS et al.. 2000. Carnosine as a regulator of soluble guanylate cyclase.. Biochemistry (Mosc) 65(7):783-8 PMID: 10951096
- 7. Spilimbergo FB et al.. 2022. Soluble Guanylate Cyclase Stimulators (Riociguat) in Pulmonary Hypertension: Data from Real-Life Clinical Practice in a 3-Year Follow-Up.. Arq Bras Cardiol 118(6):1059-1066 PMID: 35544852
- 8. Liu R et al.. 2021. Activation mechanism of human soluble guanylate cyclase by stimulators and activators.. Nat Commun 12(1):5492 PMID: 34535643
