GENERATION OF INOSITOL PHOSPHATES IN BITTER TASTE TRANSDUCTION
GENERATION OF INOSITOL PHOSPHATES IN BITTER TASTE TRANSDUCTION
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DOI：
10.1016/0031-9384(94)90359-x
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发表时间：
1994-12-01
影响因子：
2.9
通讯作者：
BRAND, JG
中科院分区：
文献类型：
--
作者：
SPIELMAN, AI;HUQUE, T;BRAND, JG
可能有多种机制参与苦味的转导。其中一种机制使用第二信使1，4，5-三磷酸肌醇(IP3)和二酰甘油(DAG)。经S孵育30天后，小鼠舌环味区和舌叶味区的部分膜制剂对已知的苦味刺激的反应是增加了肌醇磷酸的产生量。加入苦味刺激剂蔗糖八乙酸酯和G蛋白刺激剂GTP伽马S，与单独使用其中任何一种相比，肌醇磷酸酶的产量都有所增加。百日咳毒素预处理消除了对蔗糖八乙酸酯和GTP-伽马S的所有反应，而霍乱毒素预处理则不起作用。用几种G蛋白的α亚基抗体对环状和叶状区的溶解组织进行免疫印迹，发现与Gα(I1-2)和Gα(0)抗体反应的条带，而对Gα(I3)抗体没有明显的活性。根据免疫印迹和毒素实验的结果，我们认为，八醋酸蔗糖的苦味在小鼠体内的转导涉及受体介导的G(I)型蛋白的激活，该蛋白激活磷脂酶C来产生两个第二信使IP3和DAG。
It is probable that there is a diversity of mechanisms involved in the transduction of bitter taste. One of these mechanisms uses the second messengers, inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). Partial membrane preparations from circumvallate and foliate taste regions of mice tongues responded to the addition of known bitter taste stimuli by increasing the amount of inositol phosphates produced after 30 s incubation. Addition of both the bitter stimulus, sucrose octaacetate and the G-protein stimulant, GTP gamma S, led to an enhanced production of inositol phosphates compared with either alone. Pretreatment of the tissue samples with pertussis toxin eliminated all response to sucrose octaacetate plus GTP gamma S, whereas pretreatment with cholera toxin was without effect. Western blots of solubilized tissue from circumvallate and foliate regions probed with antibodies to the alpha-subunit of several types of G-proteins revealed bands reactive to antibodies against G alpha(i1-2), and G alpha(0),, with no apparent activity to antibodies against G alpha(i3). Given the results from the immunoblots and those of the toxin experiments, it is proposed that the transduction of the bitter taste of sucrose octaacetate in mice involves a receptor-mediated activation of a G(i)-type protein which activates a phospholipase C to produce the two second messengers, IP3 and DAG.