Methods of using T1R hetero-oligomeric taste receptors to screen for compounds which modulate sweet or umami taste signaling

A method of screening for compounds that modulate taste signaling transduction comprising:

• (i) contacting a first human cell co-expressing at least two different human T1R receptors or polypeptides, wherein one of said T1R receptors or polypeptides comprises human T1R3, with a known taste activating compound and a putative taste transduction modulating compound, wherein the expressed T1R receptors or polypeptides act as a hetero-oligomeric complex;
• (ii) contacting a second human cell co-expressing at least two different T1R receptors or polypeptides, wherein one of said T1R receptors or polypeptides comprises human T1R3, with a known taste activating compound alone, wherein the expressed T1R receptors or polypeptides act as a hetero-oligomeric complex;
• and
• (iii) comparing a first activity from the T1R receptors or polypeptides expressed on the cell surface of the first human cell with a second activity from the T1R receptors or polypeptides expressed on the cell surface of the second human cell, wherein a difference in the first activity and the second activity is indicative of a compound that modulates taste signaling transduction.