Bitter taste receptor type 2 member 2 (TAS2R2)

Bitter taste receptor type 2 member 2 (TAS2R2) is one of ~25 human bitter taste receptors and is part of the G protein-coupled receptor (GPCR) family. Its primary role is the detection of bitter substances in the oral cavity, aiding in aversion to potentially harmful compounds. TAS2R2 was long believed to be a pseudogene—non-functional—in most populations but has been shown to exist as a functional variant among specific groups. The receptor is tuned to respond to a moderate number of bitter substances, including several pharmacological agents not typically considered food-related. Upon activation by agonists such as phenylbutazone, TAS2R2 initiates cellular signal transduction through calcium release and membrane depolarization, culminating in transmission of taste signals to the brain. The function and pharmacological relevance of TAS2R2 are limited primarily to taste biology, with little evidence supporting direct disease association or therapeutic modulation in current practice.

Other names

T2R2T2R02PS9TAS2R2Ptaste receptor Ps9 pseudogenetaste receptor, type 2, member 2, pseudogene"Taste 2 receptor member 2"

Agonists (e.g., phenylbutazone) bind to TAS2R2 and activate the canonical GPCR cascade: - Activation of heterotrimeric G protein (Gα-gustducin, Gβ3, Gγ13) - Phospholipase Cβ2 activation → IP3/DAG production - Release of calcium from ER via IP3 receptor - Activation of TRPM5 channel, cell depolarization, action potential, and neurotransmitter (ATP) release leading to signal transmission to the brainstem