GPR132 (G protein-coupled receptor 132), also known as G2A, is a member of the proton-sensing GPCR family that functions as a cellular sensor of acidification. Originally identified as a receptor for lysophosphatidylcholine (LPC) and other lipid mediators, GPR132 has emerged as a versatile sensor of the tumor microenvironment, metabolic stress, and tissue acidosis [1][2].
GPR132 is expressed in various tissues including brain, immune cells, and metabolic organs. It plays critical roles in:
The receptor has attracted significant interest as a potential therapeutic target for cancer, metabolic disorders, and inflammatory conditions. Recent research has also revealed emerging roles in neurological diseases including Alzheimer's disease, Parkinson's disease, and stroke [3][4].
| Property | Value |
|---|---|
| Gene Symbol | GPR132 |
| Full Name | G protein-coupled receptor 132 |
| Aliases | G2A, GPR132 |
| Chromosomal Location | 14q24.2 |
| NCBI Gene ID | 29933 |
| OMIM | 616087 |
| Ensembl ID | ENSG00000168214 |
| UniProt ID | Q9Y5S2 |
| Gene Type | Protein coding |
| Gene Family | Proton-sensing GPCRs (GPR4 family) |
The GPR132 gene spans approximately 35 kb and consists of multiple exons encoding a 7-transmembrane domain GPCR of approximately 380 amino acids. The gene is located on chromosome 14q24.2, a region associated with some cancers. The promoter region contains binding sites for p53, NF-κB, and other transcription factors [5].
GPR132 is a Class A G protein-coupled receptor with unique features:
GPR132 belongs to the proton-sensing GPCR family that includes:
GPR132 activates multiple signaling pathways depending on the ligand and context:
pH-dependent signaling:
Lactate sensing:
Key downstream pathways:
GPR132 couples primarily to Gα_s, leading to cAMP production, but can also signal through Gα_i and Gα_q depending on context [6][7].
GPR132 functions as a cellular sensor of acidification:
Metabolic stress response: During hypoxia or intense metabolic activity, cells produce lactic acid and protons. GPR132 detects this acidification and triggers adaptive responses:
Tissue repair: GPR132 is activated during tissue damage when:
GPR132 is expressed in various immune cells:
| Cell Type | GPR132 Expression | Functional Significance |
|---|---|---|
| Macrophages | High | M1/M2 polarization, inflammation |
| T cells | Moderate | T cell activation and differentiation |
| NK cells | Moderate | NK cell function regulation |
| Neutrophils | Low | Some involvement in migration |
| Dendritic cells | Moderate | Antigen presentation |
Macrophage polarization: GPR132 drives macrophage M1 polarization and promotes inflammatory responses. This has implications for both host defense and inflammatory disease [8].
GPR132 plays roles in metabolic homeostasis:
Pancreatic function: GPR132 in islet-resident macrophages affects diabetes pathology through endogenous lipid mediators.
Atherosclerosis: Lactate-activated GPR132 promotes macrophage senescence and aggravates vascular complications in diabetes.
GPR132 is widely expressed:
| Tissue | Expression Level | Notes |
|---|---|---|
| Brain | Moderate | Neurons, astrocytes, microglia |
| Spleen | High | Immune cells |
| Lung | Moderate | Epithelial cells |
| Liver | Moderate | Hepatocytes, Kupffer cells |
| Kidney | Moderate | Tubular cells |
| Heart | Low-Moderate | Cardiomyocytes |
| Fat | Moderate | Adipocytes |
In the brain, GPR132 is expressed in:
Neurons: GPR132 is expressed in various neuronal populations, particularly in regions susceptible to metabolic stress:
Glial cells:
Brain regions:
GPR132 has emerging roles in Alzheimer's disease pathogenesis:
Metabolic stress: AD brains exhibit:
GPR132 may sense these changes and contribute to:
Therapeutic potential: GPR132 modulators may help:
In Parkinson's disease, GPR132 may play roles in:
Dopaminergic neuron survival: GPR132 activation may:
Microglial activation: GPR132 in microglia may contribute to:
GPR132 is strongly implicated in stroke pathophysiology:
Ischemic injury: Following stroke:
Neuroprotective potential: Studies suggest:
GPR132 plays complex roles in cancer:
Metastasis: GPR132 senses lactate and mediates tumor-macrophage interplay:
Differentiation: GPR132 activation can induce:
Diabetes: GPR132 in pancreatic islets contributes to diabetes pathology through lipid signaling in resident macrophages.
Atherosclerosis: GPR132 promotes macrophage senescence and worsens vascular complications in diabetes.
GPR132 drives macrophage M1 polarization and can:
Several GPR132-targeting strategies are in development:
Agonists:
Antagonists:
| Approach | Stage | Potential Application |
|---|---|---|
| Selective agonists | Preclinical | AML differentiation |
| Antagonists | Preclinical | Cancer, inflammation |
| Antibody-based | Discovery | Various |
| Lipid-based modulators | Preclinical | Metabolic disease |
For neurological diseases, GPR132 modulators could:
Gpr132 knockout mice (Gpr132-/-) exhibit:
GPR132 overexpression in mice leads to:
Stroke models: GPR132 is activated in ischemic tissue. Modulation affects inflammatory responses and potentially infarct size.
Cancer models: GPR132 deletion reduces metastasis in breast cancer models. Important for understanding tumor-microenvironment interactions.
EAE model: Used to study GPR132 in demyelination and neuroinflammation.