Taste receptor type 1 member 1 + Taste receptor type 1 member 3 (T1R1+T1R3)

The Taste receptor type 1 member 1 + Taste receptor type 1 member 3 (T1R1+T1R3) is a heterodimeric class C G protein-coupled receptor that functions as the primary umami taste receptor in mammals, detecting L-amino acids (especially L-glutamate) and 5'-ribonucleotides such as inosine monophosphate (IMP)[1][2][3]. The receptor is broadly expressed in taste receptor cells of the tongue and is responsible for the perception of savory or "umami" taste, which is a key component of flavor in protein-rich foods. The T1R1 subunit plays a dominant role in determining ligand specificity, with significant species differences: human T1R1+T1R3 is highly selective for L-glutamate (L-Glu), while mouse T1R1+T1R3 responds to a wider range of L-amino acids[1]. The receptor contains a large extracellular ligand-binding domain (LBD) with an orthosteric binding site for intrinsic agonists, and ligand binding induces a conformational change that activates downstream signaling pathways[2][3]. In addition to the orthosteric site, non-orthosteric sites modulate receptor activity and ligand specificity[1]. Synergistic enhancement of receptor response occurs when both amino acids and nucleotides (e.g., IMP) are present, a hallmark of umami taste perception[1][3]. The T1R1+T1R3 receptor is not currently a direct therapeutic target but is of interest for understanding taste biology and potentially for modulating flavor perception in food and nutrition[1][2][3].

Other names

Umami receptorAmino acid taste receptorT1R1/T1R3T1r1/T1r3

Ligand binding induces receptor activation leading to G protein-coupled signal transduction