L-Glutamate or L-Aspartate and 5' nucleotide bind umami taste receptor (TAS1R1:TAS1R3)

Stable Identifier
Reaction [binding]
Homo sapiens
L-Glu or L-Asp and 5' nucleotide bind TAS1R1:TAS1R3:GNAT3:GDP:GNB1,3:GNG13
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L-glutamate or L-aspartate binds the umami taste receptor, TAS1R1:TAS1R3, which is associated with a G-protein heterotrimer comprising GNAT3 (gustducin), GNB1 or GNB3, and GNG13 (Li et al. 2002, Xu et al. 2004, Zhang et al. 2008, Shigemura et al. 2009, Raliou et al. 2011, Toda et al. 2013, Narukawa et al. 2014). Whereas the mouse umami receptor responds to several L-amino acids, the human umami receptor is activated by only L-glutamate and, at a lower level, L-aspartate (Toda et al. 2013). Ribonucleotides such as 5' IMP bind an allosteric site adjacent to the glutamate-binding site and stabilize the closed conformation of the receptor, resulting in a synergistic enhancement of signaling by the receptor (Zhang et al. 2008). Polymorphisms in TAS1R1 and TAS1R3 affect binding and threshold detection of monosodium glutamate (Shigemura et al. 2009, Raliou et al. 2011). The human umami receptor also binds L-theanine, an amino acid found in green tea (Narukawa et al. 2014). Knockout of Tas1r3 (Damak et al. 2003, Delay et al. 2006, Yasumatsu et al. 2009) or Tas1r1 (Kusuhara et al. 2013) in mice does not abolish the ability to taste umami compounds indicating that other receptors such as Grm1 (mGluR1) and Grm4 (mGluR4) also detect these compounds.
Literature References
PubMed ID Title Journal Year
11917125 Human receptors for sweet and umami taste

Xu, H, Zoller, M, Staszewski, L, Li, X, Adler, E, Durick, K

Proc Natl Acad Sci U S A 2002
21422378 Human genetic polymorphisms in T1R1 and T1R3 taste receptor subunits affect their function

Briand, L, Grauso, M, Nespoulous, C, Hoffmann, B, Bano, SP, Sigoillot, M, Wiencis, A, Schlegel-Le-Poupon, C, Raliou, M, Montmayeur, JP, Trotier, D, Pernollet, JC, D├ębat, H, Belloir, C, Faurion, A

Chem Senses 2011
15353592 Different functional roles of T1R subunits in the heteromeric taste receptors

Adler, E, Tang, H, Staszewski, L, Li, X, Zoller, M, Xu, H

Proc Natl Acad Sci U S A 2004
24214976 Two distinct determinants of ligand specificity in T1R1/T1R3 (the umami taste receptor)

Ishimaru, Y, Narukawa, M, Nakagita, T, Okada, S, Hayakawa, T, Misaka, T, Imai, H, Toda, Y

J Biol Chem 2013
19696921 Genetic and molecular basis of individual differences in human umami taste perception

Shigemura, N, Shirosaki, S, Yoshida, R, Ninomiya, Y, Sanematsu, K

PLoS One 2009
19104071 Molecular mechanism for the umami taste synergism

Klebansky, B, Liu, H, Fine, RM, Li, X, Pronin, A, Tachdjian, C, Xu, H, Zhang, F

Proc Natl Acad Sci U S A 2008
24633359 L-Theanine elicits umami taste via the T1R1 + T1R3 umami taste receptor

Nakagita, T, Narukawa, M, Hayashi, Y, Misaka, T, Toda, Y

Amino Acids 2014
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