Eating worms: an unusual nicotinic acetylcholine receptor from the nematode pharynx as a potential drug target

 描述（由申请人提供）：被忽视的热带病（NTD）包括由不同肠道线虫引起的土壤传播蠕虫病（STH）。寄生虫包括蛔虫、鞭虫和钩虫。这些感染很常见。例如，蛔虫病影响全世界14亿人，在3至8岁的儿童中最常见。控制这些线虫寄生虫依赖于有效供应驱虫剂。以兽药为例，我们知道继续使用驱虫化合物进行大规模化疗会导致耐药性。需要鉴定用于驱虫剂开发的新靶位点。一旦这样的网站是烟碱乙酰胆碱受体的线虫咽。我们已经发现这种受体对目前使用的驱虫药没有反应。方法：本申请的具体目的是：1。优化C. elegans EAT-2和EAT 18和EAT 18表征所得受体。我们将研究受体表达的最佳条件，并使用一系列激动剂，拮抗剂和潜在的变构调节剂来表征所产生的受体反应。2.克隆表达A. suum eat-2和eat-18。咽部感受器是否需要其他亚单位？我们将从猪蛔虫中鉴定eat-2和eat-18的直系同源物，克隆，并在爪蟾卵母细胞中表达它们以进行表征。此外，我们将测试的假设，其他亚基基因需要形成受体。3. eat-2和eat 18联合收割机是否结合形成成熟受体？我们将检验eat-2和eat-18结合联合收割机形成功能性nAChR的新假设。在这个项目完成后，我们将在异源系统中表达一个重要的新的潜在的药物靶标寄生线虫。我们将描述一种非常新颖的nAChR（缺乏任何α亚基）。我们将在寄生线虫猪蛔虫中鉴定编码这些受体的基因。最后，我们将确定小（71 a.a.）成熟离子通道受体需要蛋白EAT-18。

 DESCRIPTION (provided by applicant): The Neglected Tropical Diseases (NTDs) include the soil-transmitted helminthiases (STHs) which are caused by diverse groups of intestinal nematodes. The parasites include Ascaris, Trichuris and hookworms. These infections are common. Ascariasis for example, affects 1.4 billion people worldwide and is most common in children between the ages of 3 and 8. Control of these nematode parasites relies on an effective supply of anthelmintics. Taking veterinary medicine as an example, we know that continued use of anthelmintic compounds for mass chemotherapy will lead to drug resistance. There is a need to identify novel target sites for anthelmintic development. Once such site is the nicotinic acetylcholine receptor on the nematode pharynx. We have discovered this receptor does not respond to currently used anrthelmintic drugs. Approach: The specific aims of this application are: 1. Optimize expression of C. elegans eat-2 and eat 18 and pharmacologically characterize the resulting receptor. We will investigate optimal conditions for receptor expression and characterize the resulting receptor responses using a range of agonists, antagonists and potential allosteric modulators. 2. Clone and express A. suum eat-2 and eat-18. Are other subunits required for the pharyngeal receptor? We will identify orthologs of eat-2 and eat-18 from Ascaris suum, clone, and express them in Xenopus oocytes for characterization. Additionally we will test the hypothesis that other subunit genes are required to form the receptor. 3. Do eat-2 and eat 18 combine to form the mature receptor? We will test the novel hypothesis that eat-2 and eat-18 combine to form a functional nAChR. On completion of this project we will have expressed in a heterologous system an important new potential drug target from a parasitic nematode. We will have characterized an extremely novel nAChR (one that lacks any alpha subunits). We will have identified the genes that encode these receptors in the parasitic nematode Ascaris suum. Finally, we will have determined whether the small (71 a.a.) protein eat-18 is required in the mature ion channel receptor.