Identification of chemoattractant receptors and G-proteins in the vomeronasal system of garter snakes.
Identification of chemoattractant receptors and G-proteins in the vomeronasal system of garter snakes.
复制标题
袜带蛇犁鼻系统中化学引诱受体和 G 蛋白的鉴定。
DOI：
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发表时间：
1994
影响因子：
4.8
通讯作者：
M. Halpern
中科院分区：
文献类型：
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作者：
Y. Luo;S. Lu;P. Chen;D. Wang;M. Halpern
束带蛇对来自猎物的纯化化学引诱物有反应。这些化学引诱物之一，ES 20，在犁鼻器的特异性结合位点是饱和的和可逆的。ES 20的结合位点通过加热被消除或通过链霉蛋白酶消化被大大减少。ES 20的化学引诱活性和受体结合需要Ca 2+。与对照动物相比，ES 20与来自双极神经元因去神经支配而耗竭的动物的感觉上皮的结合减少了22-43%。然而，神经切断后，非感觉细胞中的ES 20受体群体上调。使用免疫反应性和ADP-核糖基化技术初步鉴定了三种G蛋白（Gs、Gi和G（o））。G（o）和G（i）蛋白与ES_（20）受体和效应物偶联，表现为：1）GTP γ S降低ES_（20）受体的亲和力，2）ES_（20）受体结合引起百日咳毒素敏感G蛋白ADP核糖基化减少，而ES_（20）受体对ADP核糖基化的抑制作用被GDP β S减弱;（3）ES_（20）受体对百日咳毒素敏感G蛋白ADP核糖基化的影响可被G蛋白激活剂如GTP γ S或AlF_3所模拟：（4）ES_（20）受体结合导致cAMP基础水平降低;（5）ES_（20）与受体结合后，D-肌醇1，4，5-三磷酸水平升高。
Garter snakes respond to purified chemoattractants derived from prey. The specific binding sites for one of these chemoattractants, ES20, in the vomeronasal organ was saturable and reversible. Binding sites for ES20 were abolished by heating or greatly reduced by Pronase digestion. ES20 chemoattractant activity and receptor binding required Ca2+. Binding of ES20 to sensory epithelium derived from animals with bipolar neurons depleted by denervation was reduced 22-43% as compared to control animals. However, there was an upregulation of the ES20 receptor population in the nonsensory cells following nerve cuts. Three G-proteins (Gs, Gi, and G(o)) were tentatively identified using immunoreactivity and ADP-ribosylation techniques. Gi and G(o) proteins were shown to be coupled with ES20-receptor and effectors as evidenced by: 1) the affinity of ES20-receptor was decreased by GTP gamma S; 2) ES20-receptor binding caused a reduction in ADP-ribosylation of pertussis toxin-susceptible G-proteins, and the inhibitory effect of ES20-receptor on ADP-ribosylation was attenuated by GDP beta S; 3) the effect of ES20-receptor on ADP-ribosylation of the pertussis toxin-susceptible G-proteins could be mimicked by G-protein activators, such as GTP gamma S or AlF3; 4) ES20-receptor binding resulted in a decrease of the basal level of cAMP; 5) the binding of ES20 to its receptors caused an increase in the level of D-myo-inositol 1,4,5-trisphosphate.