Taste receptor type 2 member 4 (TAS2R4) (TAS2R4)

Taste receptor type 2 member 4 (TAS2R4) is a G protein-coupled receptor (GPCR) that belongs to the T2R family, primarily responsible for the perception of bitter taste (UniProt P59535). While traditionally associated with the tongue's gustatory cells, TAS2R4 is also expressed in extra-oral tissues such as the airway smooth muscle, the gastrointestinal tract, and the brain (PubMed: 20972434). In the lungs, activation of TAS2R4 by bitter agonists like quinine or colchicine triggers a signaling pathway that leads to bronchodilation, suggesting its potential as a therapeutic target for asthma and chronic obstructive pulmonary disease (COPD) (PubMed: 26503065). In the gut, it may play a role in the release of satiety hormones, linking it to metabolic regulation and obesity (PubMed: 21415136). The receptor is characterized by its ability to bind a diverse range of bitter ligands, including denatonium and certain antihistamines like azelastine (PubChem CID 2267). Genetic polymorphisms in the TAS2R4 gene can lead to variations in bitter taste sensitivity among individuals, which may influence dietary habits and drug compliance (PubMed: 15640388). Beyond taste, TAS2R4 is involved in innate immunity by detecting bacterial metabolites, which can trigger protective airway clearance mechanisms (PubMed: 22976355). Therapeutic development targeting TAS2R4 focuses on developing potent agonists for respiratory relief while minimizing systemic side effects. Its role in cancer cell proliferation and apoptosis is also an emerging area of research, indicating its broad biological significance (PubMed: 30135122). Overall, TAS2R4 represents a versatile target with applications ranging from sensory science to respiratory and metabolic medicine.

Other names

T2R4BTR1Bitter taste receptor 1G-protein coupled receptor 58

Agonism of the receptor leading to G protein-coupled signaling, activation of phospholipase C beta-2, and increase in intracellular calcium levels (PubMed: 20972434).