Receptor that may play a role in the perception of bitterness and is gustducin-linked. May function as a bitter taste receptor for the phytonutrient beta glucopyranosides, some of which are toxic and some of which lower the risk of cancer and cardiovascular disease. The activity of this receptor may stimulate alpha gustducin, mediate PLC-beta-2 activation and lead to the gating of TRPM5 (By similarity). Interacts with RTP3 and RTP4. 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.