Receptor that may play a role in the perception of bitterness and is gustducin-linked. May play a role in sensing the chemical composition of the gastrointestinal content. The activity of this receptor may stimulate alpha gustducin, mediate PLC-beta-2 activation and lead to the gating of TRPM5. Expressed in subsets of taste receptor cells of the tongue and palate epithelium and exclusively in gustducin-positive cells. Expressed in 15% taste bud cells in circumvallate and foliate papillae but only in 2% in fungiform papillae. Expressed in the duodenum, antrum and fundus (part of the stomach). Most taste cells may be activated by a limited number of bitter compounds; individual taste cells can discriminate among bitter stimuli. Belongs to the G-protein coupled receptor T2R family. This protein was previously referred to as T2R7 but is now considered to be the ortholog of human TAS2R13.