GO:0045028 G protein-coupled purinergic nucleotide receptor activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0045028 defines the molecular function of G protein-coupled purinergic nucleotide receptors (P2Y receptors) that bind purine nucleotides and activate heterotrimeric G-proteins.
• P2Y receptors are activated by extracellular nucleotides such as ATP, ADP, UTP, and UDP, and couple to Gq/11, Gi/o, or Gs proteins to modulate intracellular signaling.
• These receptors are expressed in diverse tissues including the nervous system, kidney, cochlea, and reproductive organs, where they regulate physiological processes.
• Dysregulated purinergic signaling via P2Y receptors is implicated in depression, kidney disease, hearing loss, and rheumatological conditions.
• P2Y receptor oligomerization can alter pharmacological properties and signaling dynamics, representing a regulatory layer for drug targeting.
• CRISPR-based knockout, knock-in, and overexpression models are essential to dissect the causal roles of P2Y receptors in health and disease.
Description
G protein-coupled purinergic nucleotide receptor activity (GO:0045028) is a molecular function that mediates cellular responses to extracellular purine nucleotides through activation of heterotrimeric G-proteins. This activity is carried out by the P2Y family of G protein-coupled receptors (GPCRs), which are widely expressed and regulate numerous physiological processes. The term encompasses the binding of purine nucleotides such as ATP and ADP, and the subsequent transmission of signals across the membrane by promoting GDP-GTP exchange on the G-protein alpha subunit. Understanding this activity is critical for researchers studying purinergic signaling in health and disease, as these receptors are involved in neurotransmission, inflammation, renal function, and sensory processing. The pharmacological and functional diversity of P2Y receptors makes them attractive targets for therapeutic intervention, and their study requires precise genetic and biochemical tools.
G protein-coupled purinergic nucleotide receptor activity At A Glance
| GO ID | GO:0045028 |
|---|---|
| GO term | G protein-coupled purinergic nucleotide receptor activity |
| Ontology | molecular_function |
| Synonym | P2Y receptor; purinergic nucleotide receptor activity, G protein coupled |
| Major function | Binding purine nucleotides and activating heterotrimeric G-proteins |
| Ligands | ATP, ADP, UTP, UDP and related purine nucleotides |
| G-protein coupling | Gq/11, Gi/o, or Gs depending on receptor subtype |
| Tissue distribution | Widespread; nervous system, kidney, cochlea, reproductive organs |
What Is GO:0045028?
According to the Gene Ontology, GO:0045028 describes the function of combining with a purine nucleotide and transmitting the signal across the membrane by activating an associated G-protein; this promotes the exchange of GDP for GTP on the alpha subunit of a heterotrimeric G-protein complex. In simpler terms, it is the activity of a receptor that detects extracellular purine nucleotides and triggers intracellular G-protein signaling.
Why Is G protein-coupled purinergic nucleotide receptor activity Important in Cell Biology?
GO:0045028 is important because P2Y receptor-mediated purinergic signaling regulates fundamental physiological processes and is implicated in multiple human diseases, including depression, kidney disorders, hearing loss, and rheumatological conditions. The ability to modulate these receptors pharmacologically or genetically offers therapeutic potential, and understanding their mechanisms is essential for drug discovery and functional genomics.
• Regulates neurotransmission and mood: astrocyte-derived ATP acting on P2Y receptors modulates depressive-like behaviors.
• Controls kidney function: purinergic signaling via P2Y receptors is involved in renal injury and disease progression.
• Essential for hearing: P2Y receptors in the cochlea regulate ion transport and protect against noise-induced hearing loss.
• Implicated in inflammation and rheumatology: P2Y receptors on immune cells contribute to inflammatory responses.
• Modulates spermatogenesis: purinergic signaling is involved in male reproductive function.
• Target for drug development: P2Y receptor subtypes are being explored for selective agonists and antagonists.
• Oligomerization affects pharmacology: P2Y receptor heteromers can alter ligand binding and signaling.
• Provides a model for GPCR signaling: P2Y receptors are prototypical purinergic GPCRs for studying G-protein activation.
What Happens During G protein-coupled purinergic nucleotide receptor activity?
Ligand binding and receptor activation
In simple terms: A purine nucleotide such as ATP or ADP binds to the receptor on the outside of the cell, causing the receptor to change shape.
The P2Y receptor binds extracellular purine nucleotides with specificity determined by its subtype; for example, some P2Y receptors prefer ATP while others prefer ADP or UTP. This binding induces conformational changes in the receptor that enable it to act as a guanine nucleotide exchange factor (GEF) for heterotrimeric G-proteins.
G-protein activation and GDP-GTP exchange
In simple terms: The activated receptor turns on a G-protein inside the cell by swapping GDP for GTP.
Upon agonist binding, the receptor interacts with the G-alpha subunit of a heterotrimeric G-protein complex, promoting the release of GDP and binding of GTP. This exchange activates the G-alpha subunit, which then dissociates from the G-beta-gamma dimer to modulate downstream effectors.
Downstream signaling pathways
In simple terms: The activated G-protein triggers a cascade of signals inside the cell.
Depending on the G-alpha subtype, P2Y receptor activation can stimulate phospholipase C (via Gq/11), inhibit adenylyl cyclase (via Gi/o), or activate adenylyl cyclase (via Gs), leading to changes in intracellular calcium, cAMP, and other second messengers. These pathways regulate diverse cellular responses such as secretion, proliferation, and gene expression.
Receptor desensitization and internalization
In simple terms: After signaling, the receptor is turned off and brought inside the cell to prevent overstimulation.
P2Y receptors undergo phosphorylation by G-protein-coupled receptor kinases (GRKs) and bind arrestins, leading to desensitization and internalization. This process is critical for terminating signaling and preventing pathological overactivation.
Key Genes Involved in GO:0045028 G protein-coupled purinergic nucleotide receptor activity
The following genes encode the P2Y receptor subtypes and associated signaling proteins that mediate GO:0045028.
| Gene | Major Role | Research Relevance |
|---|---|---|
| P2RY1 | Receptor for ATP/ADP; couples to Gq/11 | Platelet aggregation, vascular tone |
| P2RY2 | Receptor for ATP/UTP; couples to Gq/11 and Gi | Epithelial ion transport, inflammation |
| P2RY4 | Receptor for UTP; couples to Gq/11 | Smooth muscle contraction |
| P2RY6 | Receptor for UDP; couples to Gq/11 | Immune cell chemotaxis |
| P2RY11 | Receptor for ATP; couples to Gs | Neurotransmission, immune function |
| P2RY12 | Receptor for ADP; couples to Gi/o | Platelet activation, microglial motility |
| P2RY13 | Receptor for ADP; couples to Gi/o | Microglial function |
| P2RY14 | Receptor for UDP-glucose; couples to Gi/o | Immune regulation |
| GNAQ | G-alpha q subunit; mediates PLC activation | Downstream signaling of Gq-coupled P2Y receptors |
| GNAI1 | G-alpha i1 subunit; inhibits adenylyl cyclase | Downstream signaling of Gi-coupled P2Y receptors |
| GNAS | G-alpha s subunit; activates adenylyl cyclase | Downstream signaling of Gs-coupled P2Y receptors |
| ARRB1 | Beta-arrestin 1; desensitizes receptors | Receptor internalization and signaling bias |
| ARRB2 | Beta-arrestin 2; desensitizes receptors | Receptor internalization and signaling bias |
| GRK2 | G-protein-coupled receptor kinase 2; phosphorylates P2Y receptors | Desensitization |
| GRK5 | G-protein-coupled receptor kinase 5; phosphorylates P2Y receptors | Desensitization |
| PLCB1 | Phospholipase C beta 1; generates IP3 and DAG | Downstream calcium signaling |
| PRKCA | Protein kinase C alpha; modulates receptor activity | Feedback regulation |
How Is G protein-coupled purinergic nucleotide receptor activity Regulated?
P2Y receptor activity is regulated at multiple levels. Receptor oligomerization, including homodimers and heterodimers, can alter ligand binding affinity and G-protein coupling, thereby modulating signaling output. Phosphorylation by GRKs and subsequent arrestin binding mediate desensitization and internalization, which are key for terminating the signal. Additionally, the availability of extracellular nucleotides is controlled by ectonucleotidases that hydrolyze ATP and ADP, thus regulating receptor activation. In the kidney, purinergic signaling is modulated by changes in nucleotide release and degradation, which can contribute to disease progression.
G protein-coupled purinergic nucleotide receptor activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| P2RY1 | Platelet aggregation disorders | Knockout mouse; platelet function assays |
| P2RY2 | Cystic fibrosis-like ion transport defects | Knockout mouse; epithelial cell cultures |
| P2RY12 | Thrombosis; microglial dysfunction | Knock-in mouse; microglial motility assays |
| P2RY6 | Inflammatory bowel disease | Knockout mouse; colitis models |
| P2RY14 | Immune dysregulation | Knockout mouse; infection models |
Purinergic signaling in depression
Astrocyte-derived ATP acting on P2Y receptors in the brain modulates depressive-like behaviors. Studies in animal models have shown that alterations in purinergic signaling can affect mood-related circuits, suggesting that P2Y receptors are potential targets for antidepressant therapies.
P2Y receptors in kidney disease
Purinergic signaling via P2Y receptors is involved in renal injury and fibrosis. In models of kidney disease, activation of P2Y receptors can promote inflammation and fibrosis, while blockade may be protective.
Purinergic signaling in the cochlea and hearing loss
P2Y receptors in the cochlea regulate ion homeostasis and protect against noise-induced hearing loss. Dysregulation of purinergic signaling has been linked to hearing disorders, making these receptors potential therapeutic targets.
P2Y receptors in rheumatology
G protein-coupled receptors, including P2Y subtypes, play roles in inflammatory joint diseases. P2Y receptors on immune cells can modulate cytokine release and contribute to the pathogenesis of rheumatoid arthritis and other rheumatological conditions.
From G protein-coupled purinergic nucleotide receptor activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of P2RY2 affect epithelial ion transport? | P2RY2 knockout cell line (e.g., airway epithelial cells) |
| Does a point mutation in P2RY12 alter ADP sensitivity? | P2RY12 point-mutation knock-in cells |
| Can a tagged P2RY1 receptor be used to track localization? | P2RY1 tagged knock-in (e.g., GFP) cell line |
| Does overexpression of P2RY6 enhance inflammatory signaling? | P2RY6 overexpression cell line |
| Which genes are essential for P2Y receptor signaling? | CRISPR library screening in relevant cell types |
| Does P2RY14 oligomerize with other P2Y receptors? | Knock-in cells expressing fluorescently tagged receptors |
How to Study the G protein-coupled purinergic nucleotide receptor activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss of receptor function | Determining gene essentiality |
| CRISPR point mutation | Effect of specific amino acid changes | Structure-function studies |
| Knock-in tagging | Receptor localization and dynamics | Live-cell imaging |
| Overexpression | Gain-of-function and pharmacology | Drug screening |
| RNA-seq | Transcriptional changes upon receptor activation | Pathway analysis |
| Proteomics | Protein-protein interactions | Identifying signaling complexes |
| Calcium imaging | Intracellular calcium mobilization | Gq-coupled receptor activity |
| cAMP assays | Changes in cyclic AMP levels | Gi/Gs-coupled receptor activity |
CRISPR-Cas9 knockout
Knockout of specific P2Y receptor genes using CRISPR-Cas9 allows researchers to determine loss-of-function phenotypes. For example, P2RY2 knockout cells can be used to study its role in ion transport and inflammation.
CRISPR-mediated point mutations
Introducing point mutations in P2Y receptor genes can help dissect ligand-binding specificity and G-protein coupling. For instance, mutations in the DRY motif of P2RY1 can affect receptor activation.
Knock-in reporter models
Knocking in fluorescent tags (e.g., GFP) into endogenous P2Y receptor loci enables real-time imaging of receptor trafficking and localization in live cells.
Overexpression and pharmacological profiling
Overexpression of P2Y receptors in heterologous systems (e.g., HEK293 cells) is used for pharmacological characterization of agonists and antagonists, and for studying downstream signaling.
How CRISPR Can Be Used to Study GO:0045028 G protein-coupled purinergic nucleotide receptor activity
Knockout
CRISPR knockout of P2Y receptor genes is used to create isogenic cell lines that lack the receptor, enabling the study of its specific contribution to signaling and disease. For example, P2RY12 knockout microglia show impaired motility.
Point Mutation
Point mutations can be introduced to mimic naturally occurring variants or to probe functional domains. For instance, mutating the ligand-binding pocket of P2RY1 can reveal residues critical for ATP recognition.
Knock-in
Knock-in of reporter genes or epitope tags allows for tracking endogenous P2Y receptors. This is particularly useful for studying receptor trafficking and oligomerization.
Overexpression
Overexpression of P2Y receptors in cell lines is a standard approach for pharmacological profiling and for studying downstream signaling pathways in a controlled background.
How EDITGENE Supports G protein-coupled purinergic nucleotide receptor activity Research
Researchers studying G protein-coupled purinergic nucleotide receptor activity-related genes often need to determine whether a candidate gene is causally involved in a specific signaling pathway or disease phenotype. EDITGENE provides a comprehensive suite of CRISPR-based services to enable precise genetic manipulation and functional interrogation of P2Y receptors and their signaling partners.
Contact EDITGENE today to design your custom CRISPR model for G protein-coupled purinergic nucleotide receptor activity research.
Frequently Asked Questions About G protein-coupled purinergic nucleotide receptor activity
What is GO:0045028?
GO:0045028 is the Gene Ontology term for G protein-coupled purinergic nucleotide receptor activity, a molecular function where a receptor binds purine nucleotides and activates heterotrimeric G-proteins.
What genes are involved in G protein-coupled purinergic nucleotide receptor activity?
The main genes are the P2Y receptor family, including P2RY1, P2RY2, P2RY4, P2RY6, P2RY11, P2RY12, P2RY13, and P2RY14, as well as G-protein subunits and downstream effectors.
Which nucleotides activate P2Y receptors?
P2Y receptors are activated by purine nucleotides such as ATP, ADP, UTP, and UDP, with specificity depending on the receptor subtype.
What diseases are associated with P2Y receptors?
P2Y receptors are implicated in depression, kidney disease, hearing loss, and rheumatological conditions, among others.
How can I study P2Y receptor function using CRISPR?
CRISPR knockout, point mutation, knock-in, and overexpression models allow precise manipulation of P2Y receptor genes to study their roles in signaling and disease.
What is the role of P2RY12 in microglia?
P2RY12 is a Gi-coupled receptor for ADP that regulates microglial motility and process extension, and is a key marker for homeostatic microglia.
How does P2Y receptor oligomerization affect signaling?
Oligomerization can change ligand binding affinity, G-protein coupling, and downstream signaling, adding a layer of pharmacological complexity.
What experimental models are available for P2Y receptor research?
Common models include knockout mice, knockout cell lines, knock-in reporter cells, and overexpression systems, often combined with pharmacological tools.
What is the clinical relevance of purinergic signaling in the kidney?
Purinergic signaling via P2Y receptors contributes to renal injury and fibrosis, and targeting these receptors may offer therapeutic benefits.
How does ATP act as a neurotransmitter via P2Y receptors?
Astrocyte-derived ATP can activate neuronal P2Y receptors, modulating synaptic activity and behaviors such as depression-like symptoms.
Conclusion
G protein-coupled purinergic nucleotide receptor activity (GO:0045028) is a fundamental molecular function that mediates cellular responses to extracellular purine nucleotides. The P2Y receptor family and its downstream G-protein signaling pathways are critical for numerous physiological processes and are implicated in a wide range of diseases. Understanding the mechanisms, regulation, and genetic basis of this activity is essential for developing targeted therapies. EDITGENE's CRISPR services provide powerful tools to dissect these pathways and accelerate discovery in purinergic signaling research.
References
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- 2. Guo X et al.. 2021. G protein-coupled purinergic P2Y receptor oligomerization: Pharmacological changes and dynamic regulation.. Biochem Pharmacol 192:114689 PMID: 34274353
- 3. Mundt N et al.. 2022. Purinergic Signaling in Spermatogenesis.. Front Endocrinol (Lausanne) 13:867011 PMID: 35480481
- 4. von Kügelgen I. 2019. Pharmacology of P2Y receptors.. Brain Res Bull 151:12-24 PMID: 30922852
- 5. Cao X et al.. 2013. Astrocyte-derived ATP modulates depressive-like behaviors.. Nat Med 19(6):773-7 PMID: 23644515
- 6. Neumann E et al.. 2014. G protein-coupled receptors in rheumatology.. Nat Rev Rheumatol 10(7):429-36 PMID: 24798574
- 7. Vlajkovic SM et al.. 2022. Purinergic Signalling in the Cochlea.. Int J Mol Sci 23(23) PMID: 36499200
- 8. Menzies RI et al.. 2017. Purinergic signaling in kidney disease.. Kidney Int 91(2):315-323 PMID: 27780585
