Transduction of bitter and sweet taste by gustducin
Transduction of bitter and sweet taste by gustducin
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DOI：
10.1038/381796a0
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发表时间：
1996-06-27
期刊：
影响因子：
64.8
通讯作者：
Margolskee, RF
中科院分区：
文献类型：
--
作者：
Wong, GT;Gannon, KS;Margolskee, RF
SFVERAL 证据表明甜味和苦味都是通过与异三聚鸟嘌呤核苷酸结合蛋白（G 蛋白）偶联的受体转导的（参见参考文献 1、2）。味导素是一种味觉受体细胞 (TRC) 特异性 G 蛋白，与转导素密切相关 (3)。味导素和视杆转导素也在 TRC 中表达（参考文献 4），已提出将苦味反应受体与 TRC 特异性磷酸二酯酶偶联，以调节细胞内环核苷酸(2-5)。在这里，我们通过生成和表征缺乏味觉素α亚基（α味觉素）的小鼠来研究味觉素在味觉转导中的作用。正如预测的那样，突变小鼠对苦味化合物的行为和电生理反应减少，而它们对咸味和酸味刺激的反应与野生型对照没有区别。出乎意料的是，突变小鼠还表现出对甜味化合物的行为和电生理反应减少。我们的结果表明味素是苦味和甜味信号转导的主要介质。
SFVERAL lines of evidence suggest that both sweet and bitter tastes are transduced via receptors coupled to heterotrimeric guanine-nucleotide-binding proteins (G proteins) (reviewed in refs 1, 2). Gustducin is a taste receptor cell (TRC)-specific G protein that is closely related to the transducins(3). Gustducin and rod transducin, which is also expressed in TRCs (ref. 4), have been proposed to couple bitter-responsive receptors to TRC-specific phosphodiesterases to regulate intracellular cyclic nucleotides(2-5). Here we investigate gustducin's role in taste transduction by generating and characterizing mice deficient in the gustducin alpha-subunit (alpha gustducin). As predicted, the mutant mice showed reduced behavioural and electrophysiological responses to bitter compounds, whereas they were indistinguishable from wild-type controls in their responses to salty and sour stimuli. Unexpectedly, mutant mice also exhibited reduced behavioural and electrophysiological responses to sweet compounds. Our results suggest that gustducin is a principal mediator of both bitter and sweet signal transduction.