Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0235290 (bitter taste)
 1,408 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A complete understanding of bitterness perception requires identification of cognate bitter substances for all human bitter taste receptors (TAS2Rs). However, so far, no agonists have been identified for five of the 25 TAS2Rs, i.e., TAS2R41, TAS2R42, TAS2R45, TAS2R48 and TAS2R60. Due to substantial genetic variability several haplotypes exist for most bitter receptor genes. For some of the deorphaned TAS2Rs, haplotypes have been identified coding for proteins with severely impaired or even lacking receptor function, proposing that the use of non-functional receptor variants in previous investigations accounted for the failure to identify cognate bitter agonists for the orphan TAS2Rs. In the present report we reasoned that at least one out of the major genetically encoded TAS2R variants is functional. Therefore, we expressed the major haplotypes of the five orphan TAS2Rs in our functional assay and challenged the cells with 106 bitter compounds. Chloramphenicol was identified as agonist for TAS2R41. Further studies revealed that TAS2R41 is a 'specialist' receptor highly selective for this antibiotic. None of the other TAS2R variants responded to any of the 106 compounds, suggesting that the use of non-functional variants does not explain the failure to identify cognate agonists for the other four TAS2Rs. Probably, these TAS2Rs are highly selective for bitter substances absent in our compound library.
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PMID:Major haplotypes of the human bitter taste receptor TAS2R41 encode functional receptors for chloramphenicol. 2363 30

In the last decade, basic research in chemoreceptor genetics and neurobiology have revolutionized our understanding of individual differences in chemosensation. From an evolutionary perspective, chemosensory variations appear to have arisen in response to different living environments, generally in the avoidance of toxins and to better detect vital food sources. Today, it is often assumed that these differences may drive variable food preferences and choices, with downstream effects on health and wellness. A growing body of evidence indicates chemosensory variation is far more complex than previously believed. However, just because a genetic polymorphism results in altered receptor function in cultured cells or even behavioral phenotypes in the laboratory, this variation may not be sufficient to influence food choice in free living humans. Still, there is ample evidence to indicate allelic variation in TAS2R38 predicts variation in bitterness of synthetic pharmaceuticals (e.g., propylthiouracil) and natural plant compounds (e.g., goitrin), and this variation associates with differential intake of alcohol and vegetables. Further, this is only one of 25 unique bitter taste genes (TAS2Rs) in humans, and emerging evidence suggests other TAS2Rs may also contain polymorphisms that a functional with respect to ingestive behavior. For example, TAS2R16 polymorphisms are linked to the bitterness of naturally occurring plant compounds and alcoholic beverage intake, a TAS2R19 polymorphism predicts differences in quinine bitterness and grapefruit bitterness and liking, and TAS2R31 polymorphisms associate with differential bitterness of plant compounds like aristolochic acid and the sulfonyl amide sweeteners saccharin and acesulfame-K. More critically with respect to food choices, these polymorphisms may vary independently from each other within and across individuals, meaning a monolithic one-size-fits-all approach to bitterness needs to be abandoned. Nor are genetic differences restricted to bitterness. Perceptual variation has also been associated with polymorphisms in genes involved in odors associated with meat defects (boar taint), green/grassy notes, and cilantro, as well as umami and sweet tastes (TAS1R1/2/3). Here, a short primer on receptor genetics is provided, followed by a summary of current knowledge, and implications for human ingestive behavior are discussed.
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PMID:Do polymorphisms in chemosensory genes matter for human ingestive behavior? 2387 14