GO:0007188 adenylate cyclase-modulating G protein-coupled receptor signaling pathway

The adenylate cyclase-modulating G protein-coupled receptor signaling pathway (GO:0007188) is a fundamental biological process that translates extracellular signals into intracellular responses via cyclic AMP (cAMP). This pathway is initiated when an agonist binds to a G protein-coupled receptor (GPCR) that couples to Gs or Gi proteins, leading to activation or inhibition of adenylyl cyclase and subsequent changes in cAMP levels. The cAMP second messenger then activates effectors such as protein kinase A (PKA) and exchange proteins directly activated by cAMP (EPAC), which regulate diverse cellular functions including metabolism, gene expression, and cell growth. Given its central role in physiology, this pathway is a major focus in drug discovery, particularly for metabolic disorders such as diabetes and obesity. For example, glucagon-like peptide-1 receptor (GLP1R) agonists, which activate this pathway, are widely used to treat type 2 diabetes and promote weight loss. Understanding the molecular components and regulatory mechanisms of GO:0007188 is therefore critical for developing targeted therapies and for interpreting disease-associated genetic variants. In this article, we provide a research-grade overview of GO:0007188, covering its definition, key genes, regulatory mechanisms, disease associations, and experimental models. We also highlight how CRISPR-based approaches can be used to study this pathway and identify novel therapeutic targets.

GO:0007188 is defined as a G protein-coupled receptor signaling pathway in which the signal is transmitted via the activation or inhibition of adenylyl cyclase activity and a subsequent change in the intracellular concentration of cyclic AMP (cAMP). This process encompasses the series of molecular events from ligand binding to a GPCR through G protein activation, modulation of adenylyl cyclase, and downstream cAMP-dependent effector activation.

GO:0007188 is critically important because it governs a vast array of physiological processes, from glucose homeostasis and appetite regulation to cardiac function and neuronal signaling. Dysregulation of this pathway contributes to major human diseases, including type 2 diabetes, obesity, heart failure, and various cancers. Moreover, many FDA-approved drugs, such as GLP-1 receptor agonists and beta-blockers, target components of this pathway, underscoring its therapeutic relevance. Understanding the precise molecular mechanisms and identifying genetic variants that alter pathway activity can lead to more effective and personalized treatments.

The following genes encode key components of the adenylate cyclase-modulating G protein-coupled receptor signaling pathway, including receptors, G proteins, adenylyl cyclases, and downstream effectors.

The adenylate cyclase-modulating G protein-coupled receptor signaling pathway is tightly regulated at multiple levels. Receptor desensitization is mediated by GPCR kinases (GRKs) and arrestins, which uncouple the receptor from G proteins and promote internalization. Phosphodiesterases (PDEs) hydrolyze cAMP, providing a major mechanism for signal termination. Additionally, regulators of G protein signaling (RGS) proteins accelerate the intrinsic GTPase activity of G alpha subunits, shortening the duration of G protein activation. Cross-talk with other signaling pathways, such as the MAPK/ERK cascade, can modulate cAMP responses. These regulatory mechanisms ensure that the pathway responds appropriately to physiological demands and prevents aberrant signaling that could lead to disease.

Dysregulation of GLP1R signaling, a key component of GO:0007188, is central to the pathogenesis of type 2 diabetes and obesity. GLP-1 receptor agonists, which activate this pathway, enhance glucose-dependent insulin secretion and promote weight loss. Genetic variants in GLP1R have been associated with altered glycemic control and response to therapy. Targeting this pathway with CRISPR-based models can help identify novel therapeutic strategies.

Beta-adrenergic receptors (ADRB1, ADRB2) signal through GO:0007188 to regulate heart rate and contractility. Chronic activation of this pathway contributes to heart failure, and beta-blockers are a mainstay of treatment. Polymorphisms in ADRB2 affect drug response and disease progression. Studying this pathway in cardiomyocytes using CRISPR knockout or knock-in models can elucidate mechanisms of cardiac dysfunction.

Constitutive activation of Gs-coupled receptors or mutations in GNAS can lead to increased cAMP signaling, promoting cell proliferation and tumorigenesis in certain tissues. For example, mutations in GNAS are found in McCune-Albright syndrome and various endocrine tumors. Conversely, Gi-coupled receptors may inhibit cAMP and affect cancer cell growth. CRISPR screens targeting pathway components can identify vulnerabilities in cancer cells.

Dopamine D2 receptors (DRD2) are Gi-coupled and inhibit adenylyl cyclase, modulating motor control and reward. Altered DRD2 signaling is implicated in schizophrenia, Parkinson's disease, and addiction. Additionally, cAMP signaling in neurons is critical for learning and memory, with ADCY1 and CREB1 playing key roles. CRISPR models can help dissect the contribution of specific pathway genes to these disorders.

cAMP levels can be measured using luminescence-based assays (e.g., GloSensor) or ELISA. These assays are used to assess receptor activity, G protein coupling, and adenylyl cyclase function in response to ligands or genetic perturbations. They are typically applied in high-throughput screening for drug discovery.

RNA-seq measures global gene expression changes following activation or inhibition of the pathway. It can identify cAMP-responsive genes and reveal transcriptional networks regulated by CREB. This method is useful for understanding downstream effects of pathway modulation in various cell types.

Mass spectrometry-based proteomics can quantify protein abundance and phosphorylation events mediated by PKA and other kinases. Phosphoproteomics identifies direct substrates of PKA, providing insights into signaling networks. This approach is applied to map pathway cross-talk and identify biomarkers.

Fluorescent biosensors (e.g., EPAC-based cAMP sensors) allow real-time visualization of cAMP dynamics in living cells. Imaging can track receptor internalization and subcellular localization of pathway components. This method is used to study spatiotemporal regulation of the pathway.

Researchers studying adenylate cyclase-modulating G protein-coupled receptor signaling pathway-related genes often need to determine whether a candidate gene is causally involved in pathway regulation, disease pathogenesis, or drug response. EDITGENE provides a comprehensive suite of CRISPR-based services to enable precise genetic manipulation and functional interrogation of this pathway.

The adenylate cyclase-modulating G protein-coupled receptor signaling pathway (GO:0007188) is a central biological process that controls diverse physiological functions through cAMP. Its dysregulation underlies major human diseases, and it remains a fertile ground for drug discovery. CRISPR-based models are indispensable for dissecting the causal roles of pathway components and for identifying new therapeutic targets. EDITGENE offers comprehensive services to support such research, from custom cell line generation to high-throughput screening and bioinformatics.