GO:0007187 G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0007187 describes GPCR signaling that transmits signals by activating or inhibiting nucleotide cyclases and changing cyclic nucleotide concentrations.
• The pathway converts extracellular stimuli into intracellular cyclic AMP or cyclic GMP signals through heterotrimeric G proteins.
• Receptor endocytosis can sustain G protein signaling from endosomes, expanding the signaling repertoire beyond the plasma membrane.
• cAMP nanodomains generated by receptor-associated independent pools provide spatiotemporal specificity to GPCR signaling.
• Gs-coupled receptors can diversify Ca2+ signaling through mechanisms beyond canonical cyclic nucleotide changes.
• Dysregulation of this pathway is linked to vascular, retinal, and inflammatory disease processes.
Description
G protein-coupled receptors (GPCRs) constitute the largest family of cell surface receptors and mediate responses to hormones, neurotransmitters, and environmental cues. GO:0007187, G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger, defines the subset of GPCR pathways in which signal transmission occurs through activation or inhibition of a nucleotide cyclase and a subsequent change in cyclic nucleotide concentration. This term is central to understanding how cells convert extracellular signals into rapid intracellular changes in cAMP or cGMP. The pathway is initiated when an agonist-bound GPCR acts as a guanine nucleotide exchange factor for a heterotrimeric G protein, promoting exchange of GDP for GTP on the G-alpha subunit. Depending on the G-alpha subtype, the activated G protein can stimulate or inhibit adenylyl cyclase, or activate guanylyl cyclase, thereby altering cyclic nucleotide levels and downstream effector activity. Beyond the plasma membrane, GPCRs can continue signaling after internalization, with endosomal G protein activation contributing to sustained cyclic nucleotide production. Recent work has also revealed that cAMP is organized into nanodomains that are generated independently of receptor association, providing spatial and temporal specificity to signaling outputs. In addition, Gs-coupled receptors can diversify Ca2+ signaling through pathways that extend beyond canonical cyclic nucleotide changes. Because this pathway controls processes ranging from vascular tone to phototransduction, it is a major focus in pharmacology and disease research.
G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger At A Glance
| GO ID | GO:0007187 |
|---|---|
| GO term | G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger |
| Ontology | biological_process |
| Synonym | GPCR signaling pathway via cyclic nucleotide second messenger; G-protein coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger; G protein signaling, coupled to cyclic nucleotide second messenger |
| Major function | Transmits extracellular signals into intracellular changes in cyclic nucleotide concentration via GPCRs and heterotrimeric G proteins |
| Second messengers | Cyclic AMP (cAMP) and cyclic GMP (cGMP) |
| Key enzymes | Adenylyl cyclase and guanylyl cyclase |
| Cellular locations | Plasma membrane and endosomes |
| Related signaling | Gs-, Gi/o-, and Gq-coupled receptor pathways that converge on cyclic nucleotide regulation |
What Is GO:0007187?
GO:0007187 is a biological process term describing a G protein-coupled receptor signaling pathway in which the signal is transmitted via the activation or inhibition of a nucleotide cyclase activity and a subsequent change in the concentration of a cyclic nucleotide. In other words, an extracellular ligand binds a GPCR, the receptor activates a heterotrimeric G protein, and the G protein then modulates an enzyme that makes or breaks cyclic nucleotides such as cAMP or cGMP. The resulting change in cyclic nucleotide concentration alters the activity of downstream effectors, thereby propagating the signal inside the cell.
Why Is G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger Important in Cell Biology?
GO:0007187 is important because it defines one of the most widespread and therapeutically targeted signaling mechanisms in human cells. Many drugs act by modulating GPCRs that couple to cyclic nucleotide second messengers, and the pathway controls heart rate, vascular tone, neurotransmission, metabolism, and sensory transduction. Understanding its molecular logic is essential for interpreting how cells achieve signaling specificity and how dysregulation contributes to disease.
• Controls vascular tone and blood pressure through endothelial adrenomedullin signaling.
• Mediates retinal phototransduction, converting light signals into electrical responses.
• Regulates cAMP nanodomains that provide spatiotemporal specificity to GPCR signaling.
• Enables sustained signaling from endosomes after receptor internalization.
• Provides a mechanism for Gs-coupled receptors to diversify Ca2+ signaling.
• Is a major target of pharmacological agents acting on GPCRs.
• Links extracellular stimuli to cyclic nucleotide-dependent effectors such as PKA and EPAC.
• Contributes to proton-sensing and adhesion GPCR biology in diverse physiological contexts.
What Happens During G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger?
Ligand binding and receptor activation
In simple terms: A signal molecule binds to a receptor on the cell surface, turning the receptor on.
The pathway begins when an extracellular agonist binds to a GPCR, stabilizing an active receptor conformation. This active receptor acts as a guanine nucleotide exchange factor for a heterotrimeric G protein, promoting GDP-to-GTP exchange on the G-alpha subunit. Receptor activation is the first committed step that determines whether the pathway will stimulate or inhibit cyclic nucleotide production.
Heterotrimeric G protein cycling
In simple terms: The activated receptor switches on a G protein, which then separates into active pieces.
GTP binding to G-alpha causes dissociation of the heterotrimer into G-alpha-GTP and G-beta-gamma dimers. These active species then engage downstream effectors, including nucleotide cyclases. The duration of signaling is controlled by the intrinsic GTPase activity of G-alpha, which hydrolyzes GTP to GDP and terminates the active state.
Nucleotide cyclase activation or inhibition
In simple terms: The G protein tells an enzyme to make more or less cyclic nucleotide.
Depending on the G-alpha subtype, the activated G protein can stimulate adenylyl cyclase to increase cAMP, inhibit adenylyl cyclase to decrease cAMP, or activate guanylyl cyclase to increase cGMP. This step is the defining feature of GO:0007187, because the signal is transmitted through a change in cyclic nucleotide concentration.
Cyclic nucleotide effectors and cellular responses
In simple terms: The cyclic nucleotide acts as a messenger that changes the behavior of the cell.
cAMP and cGMP bind to effector proteins such as protein kinase A, EPAC, and cyclic nucleotide-gated channels, altering their activity. These effectors then modify downstream targets to produce physiological responses. Recent work shows that cAMP is organized into nanodomains that can be generated independently of receptor association, providing spatial and temporal specificity to signaling.
Endosomal signaling and signal diversification
In simple terms: The receptor can keep signaling after it moves inside the cell.
After agonist binding, many GPCRs are internalized into endosomes, where they can continue to activate G proteins and produce cyclic nucleotides. This endosomal phase contributes to sustained signaling and to distinct cellular outcomes. In addition, Gs-coupled receptors can diversify Ca2+ signaling through mechanisms that extend beyond canonical cyclic nucleotide changes.
Key Genes Involved in GO:0007187 G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger
The following genes and proteins are central to GO:0007187, based on their established roles in GPCR signaling coupled to cyclic nucleotide second messengers.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ADRB1 | Beta-1 adrenergic receptor that couples to Gs and stimulates adenylyl cyclase | Cardiac and vascular signaling studies |
| ADRB2 | Beta-2 adrenergic receptor that couples to Gs and regulates cAMP | Airway and metabolic research |
| ADORA2A | Adenosine A2A receptor that activates Gs and increases cAMP | Neuroinflammation and Parkinson's disease models |
| DRD1 | Dopamine D1 receptor that couples to Gs and stimulates cAMP | Reward and motor circuit research |
| DRD2 | Dopamine D2 receptor that couples to Gi and inhibits cAMP | Schizophrenia and addiction studies |
| HTR6 | Serotonin 5-HT6 receptor that couples to Gs and increases cAMP | Cognitive and neurodegenerative research |
| OPRM1 | Mu-opioid receptor that couples to Gi and inhibits cAMP | Pain and addiction research |
| CNR1 | Cannabinoid receptor 1 that couples to Gi and inhibits cAMP | Metabolic and neurological studies |
| ADM | Adrenomedullin ligand that signals through GPCRs to regulate vascular tone | Blood pressure and endothelial biology |
| CALCRL | Calcitonin receptor-like receptor that partners with RAMP proteins | Vascular and lymphatic signaling |
| RAMP2 | Receptor activity-modifying protein that modulates CALCRL signaling | Adrenomedullin signaling studies |
| GNAI1 | Gi alpha subunit that inhibits adenylyl cyclase | GPCR signaling specificity research |
| GNAS | Gs alpha subunit that stimulates adenylyl cyclase | cAMP pathway studies |
| ADCY1 | Adenylyl cyclase isoform that produces cAMP | Cyclic nucleotide signaling research |
| ADCY5 | Adenylyl cyclase isoform involved in cAMP generation | Metabolic and cardiac studies |
| PRKACA | Catalytic subunit of protein kinase A, a major cAMP effector | Downstream signaling research |
| RAPGEF3 | EPAC1, a cAMP-activated exchange factor | cAMP effector studies |
How Is G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger Regulated?
The pathway is regulated at multiple levels. Receptor desensitization, internalization, and recycling control the duration and location of signaling. G protein signaling is terminated by GTP hydrolysis on G-alpha, and regulators of G protein signaling (RGS) proteins accelerate this process. Cyclic nucleotide levels are further shaped by phosphodiesterases that degrade cAMP and cGMP. Recent evidence indicates that cAMP nanodomains are generated independently of receptor association, providing an additional layer of spatial regulation. Endosomal signaling also contributes to sustained cyclic nucleotide production after internalization.
G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ADM | Vascular tone and blood pressure regulation | Endothelial cell knockout of ADM |
| CALCRL | Adrenomedullin signaling in vasculature | Knockout or knockdown in endothelial cells |
| RAMP2 | Vascular GPCR signaling | Knock-in of tagged RAMP2 for imaging |
| GNAS | cAMP signaling in development and disease | Point mutation of GNAS in cell lines |
| PRKACA | cAMP effector in cardiac and metabolic disease | Overexpression of PRKACA in cardiomyocytes |
Vascular and cardiovascular disease
Shear stress-induced endothelial adrenomedullin signaling regulates vascular tone and blood pressure, and this process depends on GPCR signaling coupled to cyclic nucleotide second messengers. Dysregulation of such pathways can contribute to hypertension and vascular dysfunction.
Retinal and sensory disorders
Retinal phototransduction relies on GPCR signaling coupled to cyclic nucleotide second messengers, converting light into electrical signals in photoreceptors. Defects in this pathway can lead to visual impairment.
Neurological and psychiatric conditions
GPCRs that couple to cyclic nucleotide second messengers, such as dopamine and serotonin receptors, are major targets in neuropsychiatric research. Altered cAMP signaling has been implicated in mood disorders, addiction, and neurodegenerative processes.
Inflammation and immune regulation
Adhesion GPCRs and other GPCRs coupled to cyclic nucleotide signaling participate in immune cell migration and inflammatory responses. Targeting these pathways is an active area of drug discovery.
From G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does a GPCR gene drive cyclic nucleotide changes? | Knockout cell line |
| Does a specific mutation alter G protein coupling? | Point mutation knock-in |
| Where does the receptor signal after internalization? | Tagged knock-in for live imaging |
| Does overexpression of an effector change downstream output? | Overexpression cell model |
| Which genes regulate cAMP nanodomains? | CRISPR library screening |
| How does a ligand affect vascular tone? | Endothelial knockout model |
How to Study the G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell cAMP biosensor imaging | Real-time cAMP concentration and localization | GPCR signaling dynamics |
| Endosomal signaling assay | G protein activation from endosomes | Receptor trafficking studies |
| CRISPR knockout screen | Genes required for pathway activity | Discovery of novel regulators |
| GTP binding assay | G protein activation state | Receptor-G protein coupling |
| Phosphodiesterase activity assay | Cyclic nucleotide degradation | Regulation of cAMP/cGMP levels |
| RNA-seq | Transcriptional changes downstream of signaling | Pathway target identification |
| Proteomics | Protein interactions and post-translational modifications | Signaling complex analysis |
Live-cell cAMP and cGMP imaging
Genetically encoded biosensors allow real-time measurement of cyclic nucleotide dynamics in living cells. These tools have revealed that cAMP is organized into nanodomains with distinct spatial and temporal properties.
Endosomal signaling assays
Biochemical and imaging approaches can distinguish plasma membrane from endosomal G protein activation. Such studies have shown that GPCRs continue to signal from endosomes, contributing to sustained cyclic nucleotide production.
CRISPR-based genetic screens
Pooled CRISPR knockout or activation screens can identify genes that regulate GPCR signaling coupled to cyclic nucleotide second messengers. These screens are useful for discovering novel modulators of the pathway.
Biochemical GTP binding and hydrolysis assays
G protein activation can be measured by GTP binding or GTPase assays. These methods quantify the exchange of GDP for GTP on G-alpha subunits and the termination of signaling.
How CRISPR Can Be Used to Study GO:0007187 G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger
Knockout
CRISPR knockout of GPCR genes or their downstream effectors can abolish cyclic nucleotide signaling, allowing researchers to test causality. For example, knocking out ADM or CALCRL in endothelial cells can reveal their role in vascular tone.
Point Mutation
Point mutations can be introduced to mimic disease-associated variants or to disrupt specific G protein coupling interfaces. This approach helps dissect how individual residues control signaling specificity.
Knock-in
Knock-in of tagged receptors or effectors enables live-cell imaging and biochemical purification. Tagged knock-in models have been used to track receptor trafficking and endosomal signaling.
Overexpression
Overexpression of GPCRs or cyclic nucleotide effectors can amplify pathway output and facilitate drug screening. This approach is useful for studying gain-of-function mechanisms in disease models.
How EDITGENE Supports G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger Research
Researchers studying G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger-related genes often need to determine whether a candidate gene is causally involved in pathway activity or disease. EDITGENE provides a comprehensive suite of CRISPR-based services to enable such studies, from gene knockout to precise point mutations and knock-in models.
Contact EDITGENE today to design your custom CRISPR model for G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger research.
Frequently Asked Questions About G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger
What is GO:0007187?
GO:0007187 is a Gene Ontology biological process term for G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger, where GPCR activation leads to changes in cyclic nucleotide concentrations.
What genes are involved in G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger?
Key genes include ADRB1, ADRB2, ADORA2A, DRD1, DRD2, GNAS, GNAI1, ADCY1, ADCY5, and PRKACA, among others.
How does GPCR signaling increase cAMP?
Activated Gs-coupled receptors stimulate adenylyl cyclase, which converts ATP to cAMP, increasing intracellular cAMP levels.
What is the role of endosomal GPCR signaling?
GPCRs can continue to activate G proteins from endosomes after internalization, leading to sustained cyclic nucleotide production.
What are cAMP nanodomains?
cAMP nanodomains are localized regions of cAMP signaling that provide spatial and temporal specificity, and they can be generated independently of receptor association.
Which diseases are linked to GPCR-cyclic nucleotide signaling?
This pathway is linked to vascular disease, retinal disorders, neurological conditions, and inflammation.
How can CRISPR be used to study GPCR signaling?
CRISPR knockout, point mutation, knock-in, and overexpression models allow researchers to test gene function in cyclic nucleotide signaling.
What methods measure cyclic nucleotide changes?
Live-cell biosensors, GTP binding assays, and phosphodiesterase assays are commonly used to measure cyclic nucleotide dynamics.
What is the difference between Gs and Gi signaling?
Gs stimulates adenylyl cyclase to increase cAMP, while Gi inhibits adenylyl cyclase to decrease cAMP.
Why is GO:0007187 important for drug discovery?
Many drugs target GPCRs that couple to cyclic nucleotide second messengers, making this pathway a major focus for therapeutic development.
Conclusion
GO:0007187 captures a fundamental mechanism by which cells translate extracellular signals into intracellular cyclic nucleotide changes. Its components, from GPCRs to G proteins and cyclases, are widely studied for their roles in physiology and disease. Advances in imaging, CRISPR screening, and endosomal signaling research continue to refine our understanding of this pathway. Targeting this pathway remains a promising strategy for treating vascular, retinal, and neurological disorders.
References
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- 3. Iring A et al.. 2019. Shear stress-induced endothelial adrenomedullin signaling regulates vascular tone and blood pressure.. J Clin Invest 129(7):2775-2791 PMID: 31205027
- 4. Ludwig MG et al.. 2003. Proton-sensing G-protein-coupled receptors.. Nature 425(6953):93-8 PMID: 12955148
- 5. Brands J et al.. 2024. A molecular mechanism to diversify Ca(2+) signaling downstream of Gs protein-coupled receptors.. Nat Commun 15(1):7684 PMID: 39227390
- 6. Mannu GS. 2014. Retinal phototransduction.. Neurosciences (Riyadh) 19(4):275-80 PMID: 25274585
- 7. Anton SE et al.. 2022. Receptor-associated independent cAMP nanodomains mediate spatiotemporal specificity of GPCR signaling.. Cell 185(7):1130-1142.e11 PMID: 35294858
- 8. Tsvetanova NG et al.. 2015. G protein-coupled receptor (GPCR) signaling via heterotrimeric G proteins from endosomes.. J Biol Chem 290(11):6689-96 PMID: 25605726
