G-protein Coupled Neuropeptide Receptors in Ascaris suum

描述（由申请方提供）：寄生线虫仍然是全世界人类和牲畜发病和死亡的主要原因。控制的负担主要福尔斯在化疗药物上，但令人担忧的是，对许多抗线虫药物的耐药性正变得越来越普遍。迫切需要新的药物。FMRFamide样肽（FLP）是一个复杂的小家族，结构相关的无脊椎动物神经肽，普遍存在于所有线虫的神经系统中。大多数FLP对一系列线虫肌肉产生显著有效的作用，在低至1 pM的浓度下诱导深刻的收缩和舒张。它们的分布和生理效应表明FLP是控制线虫运动、摄食和繁殖的基础。因此，它们的受体是有吸引力的新型药物靶点。近年来，在秀丽隐杆线虫中发现了许多具有FLP配体的G蛋白偶联受体（GPCR）。在这里，它建议使用这些信息来确定FLP受体的寄生线虫，猪蛔虫。本研究的具体目的是：（1）验证与C.线虫FLP受体在A.（2）验证这些受体的配体是内源性A.我的FLPs双枝藻A.猪蛔虫FLP受体，通过使用C. elegans序列，将使用RACE PCR充分表征。这些受体将在异源系统中功能性表达，并用已知的A.我的FLPs将使用FLEXstation II（Molecular Devices）鉴定FLP配体，以监测与受体活化相关的升高的细胞内钙水平。这个为期两年的项目的成功完成将产生第一个寄生线虫神经肽受体的结构和功能信息。这将有助于进一步的实验，以提供一个更好地了解这个重要的神经递质家族在线虫的生物学。它还将为药物开发研究提供底物。

DESCRIPTION (provided by applicant): Parasitic nematodes remain a major cause of morbidity and mortality to humans and livestock throughout the world. The burden of control falls mainly on chemotherapeutics but alarmingly, resistance to many anti-nematode drugs is becoming increasingly prevalent. There is pressing need for new drugs. FMRFamide-like peptides (FLPs) are a complex family of small, structurally-related invertebrate neuropeptides that are ubiquitous in the nervous systems of all nematodes. Most FLPs elicit remarkably potent effects on a range of nematode muscles, inducing profound contractions and relaxations at concentrations as low as 1 pM. Their distribution and physiological effects indicate FLPs are fundamental to the control of nematode locomotion, feeding and reproduction. Their receptors are therefore attractive novel drug targets. Recently, a number of G protein-coupled receptors (GPCRs) with FLP ligands have been identified in Caenorhabditis elegans. Here, it is proposed to use this information to identify FLP receptors in the parasitic nematode, Ascaris suum. The specific aims of the proposal are (1) to test the hypothesis that GPCRs with high homology to the C. elegans FLP receptors are expressed in A. suum and (2) to test the hypothesis that the ligands for these receptors are endogenous A. suum FLPs. Candidiate A. suum FLP receptors, identified from the Ascaris EST database through BLAST searches using the C. elegans sequences, will be fully characterized using RACE PCR. These receptors will be functionally expressed in a heterologous system and screened with known A. suum FLPs. FLP ligands will be identified using FLEXstation II (Molecular Devices) to monitor elevated intracellular calcium levels associated with receptor activation. Successful completion of this two-year project would produce structural and functional information on the first parasitic nematode neuropeptide receptor. It would facilitate further experiments to provide a better understanding of the biology of this important family of neurotransmitters in nematodes. It would also provide a substrate for drug development studies.