Evidence for a heterodimeric sweet receptor. The sensitivity to sweetness of mice with genes for T1R1 only, both T1R1 and T1R2, both T1R1 and T1R3, or both T1R2 and T1R3 was determined by observing the relative rates at which they licked solutions containing various amounts of sucrose. These studies revealed that both T1R2 and T1R3 were required for a full response to sucrose.
[Data from G. Q. Zhao et al., Cell 115:255–