Gustducin-coupled receptor for denatonium and N(6)-propyl-2-thiouracil implicated in the perception of bitter compounds in the oral cavity and the gastrointestinal tract. Signals through PLCB2 and the calcium-regulated cation channel TRPM5. In airway epithelial cells, binding of denatonium increases the intracellular calcium ion concentration and stimulates ciliary beat frequency. In airway epithelial cells, localizes to motile cilia. Expressed in subsets of taste receptor cells of the tongue and palate epithelium and exclusively in gustducin-positive cells. Expressed on airway ciliated epithelium. Several bitter taste receptors are expressed in a single taste receptor cell. Belongs to the G-protein coupled receptor T2R family. A tail of protection - Issue 119 of July 2010