Amino acid residues of bitter taste receptor TAS2R16 that determine sensitivity in primates to β-glycosides.
Amino acid residues of bitter taste receptor TAS2R16 that determine sensitivity in primates to β-glycosides.
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DOI：
10.2142/biophysico.13.0_165
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发表时间：
2016
影响因子：
1.5
通讯作者：
Hirai H
中科院分区：
文献类型：
--
作者：
Imai H;Suzuki-Hashido N;Ishimaru Y;Sakurai T;Yin L;Pan W;Ishiguro M;Masuda K;Abe K;Misaka T;Hirai H
在哺乳动物中，苦味是由TAS2Rs介导的，TAS2Rs属于七个跨膜G蛋白偶联受体家族。由于TAS2Rs直接参与哺乳动物与其饮食来源之间的相互作用，这些基因很可能是为了反映哺乳动物进化过程中物种特有的饮食而进化的。在这里，我们使用培养的细胞表达系统分析了导致不同灵长类动物TAS2R16敏感性差异的氨基酸。我们发现TAS2R16对几个氨基酸残基的敏感性不同。人和语言中E86T、L247M和V260F的氨基酸残基突变以模拟猕猴TAS2R16的方式降低了受体的敏感性，这表明它可能通过直接相互作用对水杨素的效力做出贡献。然而，位于第4螺旋的人TAS2R16的125和133位氨基酸残基突变为猕猴序列，增加了受体的敏感性。这些结果表明，苦味敏感性可能是通过取代不同灵长类物种中TAS2Rs的特定氨基酸残基来适应特定物种的食物而独立进化的。
In mammals, bitter taste is mediated by TAS2Rs, which belong to the family of seven transmembrane G protein-coupled receptors. Since TAS2Rs are directly involved in the interaction between mammals and their dietary sources, it is likely that these genes evolved to reflect species-specific diets during mammalian evolution. Here, we analyzed the amino acids responsible for the difference in sensitivities of TAS2R16s of various primates using a cultured cell expression system. We found that the sensitivity of TAS2R16 varied due to several amino acid residues. Mutation of amino acid residues at E86T, L247M, and V260F in human and langur TAS2R16 for mimicking the macaque TAS2R16 decreased the sensitivity of the receptor in an additive manner, which suggests its contribution to the potency of salicin, possibly via direct interaction. However, mutation of amino acid residues 125 and 133 in human TAS2R16, which are situated in helix 4, to the macaque sequence increased the sensitivity of the receptor. These results suggest the possibility that bitter taste sensitivities evolved independently by replacing specific amino acid residues of TAS2Rs in different primate species to adapt to species-specific food.