REGULATION OF PHARYNGEAL PUMPING IN PARASITIC NEMATODES

描述（由申请人提供）：生物胺，如血清素、酪胺、章鱼胺和多巴胺，调节寄生线虫的一些关键过程，包括进食、咽泵、运动、产卵和许多更复杂的行为。在之前的资助期间，我们已经开始表征自由生活和寄生线虫中许多生物胺受体的药理学，偶联和定位，目的是确定调节这些关键过程的特定受体。在这些研究过程中，我们还发现了一种新的酪胺能信号通路和突触前5-HT受体连接的信号复合物，这些信号复合物由含有支架蛋白的多pdz结构域定位，似乎对有效的信号转导至关重要。本研究的重点是确定寄生虫蛔虫（Ascaris suum）中调节咽泵的生物胺受体，假设干扰这些受体，特别是通过刺激抑制性输入，如伊维菌素和谷氨酸门控氯通道所描述的那样，将对蠕虫产生有害影响。此外，我们假设受体定位对于有效的信号转导可能与受体功能一样重要，并计划使用突变体和“显性阴性”方法来验证这一假设，一旦这些多蛋白信号复合物的其他成分通过直接蛋白质相互作用和体内共定位得到证实。

DESCRIPTION (provided by the applicant): Biogenic amines, such as serotonin, tyramine, octopamine and dopamine regulate a number of key processes in parasitic nematodes, including, feeding, pharyngeal pumping, locomotion, egg-laying and many more complex behaviors. During the previous grant period, we have begun to characterize the pharmacology, coupling and localization of a number of biogenic amine receptors in both free-living and parasitic nematodes with the goal of identifying the specific receptors regulating these key processes. During the course of these studies, we have also identified a novel tyraminergeric signaling pathway and presynaptic 5-HT receptor-linked signaling complexes that are localized by a multi-PDZ domain containing scaffolding protein that appear to be essential for efficient signal transduction. The present study is focused on the definitive identification of the biogenic amine receptors regulating pharyngeal pumping in the parasitic nematode, Ascaris suum, on the assumption that interference with these receptors, especially by stimulating inhibitory inputs, as has been described for ivermectin and glutamate-gated chloride channels, will have a deleterious effect of the worms. In addition, we hypothesize that receptor localization can be as important as receptor function for effective signal transduction and plan to test this hypothesis using mutants and a "dominant negative" approach, once the other components of these multi-protein signaling complexes have been confirmed by direct protein interaction and in vivo co-localization.