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 (By similarity). 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.