Perceptual variation in umami taste and polymorphisms in TAS1R taste receptor genes

Qing Ying Chen, Suzanne Alarcon, Anilet Tharp, Osama M. Ahmed, Nelsa L. Estrella, Tiffani A. Greene, Joseph Rucker, Paul A.S. Breslin

Research output: Contribution to journalArticlepeer-review

115 Scopus citations

Abstract

Background: The TAS1R1 and TAS1R3 G protein-coupled receptors are believed to function in combination as a heteromeric glutamate taste receptor in humans. Objective: We hypothesized that variations in the umami perception of glutamate would correlate with variations in the sequence of these 2 genes, if they contribute directly to umami taste. Design: In this study, we first characterized the general sensitivity to glutamate in a sample population of 242 subjects. We performed these experiments by sequencing the coding regions of the genomic TAS1R1 and TAS1R3 genes in a separate set of 87 individuals who were tested repeatedly with monopotassium glutamate (MPG) solutions. Last, we tested the role of the candidate umami taste receptor hTAS1R1-hTAS1R3 in a functional expression assay. Results: A subset of subjects displays extremes of sensitivity, and a battery of different psychophysical tests validated this observation. Statistical analysis showed that the rare T allele of single nucleotide polymorphism (SNP) R757C in TAS1R3 led to a doubling of umami ratings of 25 mmol MPG/L. Other suggestive SNPs of TAS1R3 include the A allele of A5T and the A allele of R247H, which both resulted in an approximate doubling of umami ratings of 200 mmol MPG/L. We confirmed the potential role of the human TAS1R1-TAS1R3 heteromer receptor in umami taste by recording responses, specifically to L-glutamate and inosine 5′-monophosphate (IMP) mixtures in a heterologous expression assay in HEK (human embryonic kidney) T cells. Conclusions: There is a reliable and valid variation in human umami taste of L-glutamate. Variations in perception of umami taste correlated with variations in the human TAS1R3 gene. The putative human taste receptor TAS1R1-TAS1R3 responds specifically to L-glutamate mixed with the ribonucleotide IMP. Thus, this receptor likely contributes to human umami taste perception.

Original languageEnglish (US)
Pages (from-to)770S-779S
JournalAmerican Journal of Clinical Nutrition
Volume90
Issue number3
DOIs
StatePublished - Sep 1 2009

All Science Journal Classification (ASJC) codes

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

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