Genetic Analysis of Conotoxin Targets

描述（由申请人提供）：拟议研究的目标是为突触和神经功能的研究提供基于遗传的药理学。来自肉食性芋螺属蜗牛物种毒液的毒素的巨大多样性提供了一种天然的基于组合的药理学，其可用于选择性地结合介导突触通信的大而多样的神经递质受体组的成员。我们建议使用C。这种新的毒素将引起广大神经生物学家的兴趣。我们有三个主要目标。第一个目的是鉴定和纯化芋螺毒液中干扰土壤线虫C. elegans通过扰乱神经系统功能。这一策略的长期目标是使用芋螺毒素作为特异性探针，这将允许识别有助于神经系统功能的新基因产物。第二个目标是鉴定和纯化阻断C.优雅这些毒素对C. elegans神经生物学家，并将允许在C.目前还不可能，因为缺乏特定的药理学试剂来急性阻断特定类别的电流。我们将使用遗传学和电生理学策略来确定纯化的芋螺毒素的作用部位和机制。我们还使用组织特异性启动子在转基因蠕虫中表达活性芋螺毒素。芋螺Im1毒素阻断神经肌肉接头处大约50%的乙酰胆碱门控电流。目前还没有确定的基因产物，有助于这Im1敏感电流。使用一种新的遗传策略，我们将确定这部分突触胆碱能电流所需的基因产物。芋螺肽固有的巨大多样性，特异性和有效的受体相互作用，以及这些肽可以以组织特异性方式在转基因生物中表达的事实，可能在未来为设计神经系统疾病的遗传疗法提供框架。

DESCRIPTION (provided by applicant): The goal of the proposed research is to provide a genetic-based pharmacology for the study of synaptic and neural function. The tremendous diversity of toxins from the venoms of predatory Conus snail species provide a natural combinatorial-based pharmacology that can be used to selectively bind to the members of the large and diverse group of neurotransmitter receptors that mediate synaptic communication. We propose to use C. elegans to rapidly purify new toxins that will be of interest to the broad community of neurobiologists. We have three major aims. The first aim is to identify and purify peptide toxins from the venoms of Conus snails that disrupt the behavior of the soil nematode C. elegans by perturbing nervous system function. A long-term goal of this strategy is to use Conus toxins as specific probes that will permit the identification of new gene products that contribute to nervous system function. The second aim is to identify and purify peptide toxins that block specific ligand-gated currents in muscles and neurons of C. elegans. These toxins will be invaluable for C. elegans neurobiologists and will allow for detailed mechanistic studies of synaptic transmission in C. elegans that currently are not possible because of the lack of specific pharmacological agents to acutely block specific classes of currents. We will use genetic and electrophysiological strategies to determine the site and mechanism of action of the purified Conus toxins. We have also used tissue-specific promoters to express active Conus toxins in transgenic worms. The Conus Im1 toxin blocks approximately 50% of the ACh-gated current at the neuromuscular junction. The gene products that contribute to this Im1-sensitive current have not yet been identified. Using a new genetic strategy, we will identify gene products that are required for this portion of the synaptic cholinergic current. The tremendous diversity inherent in Conus peptides, the specific and potent receptor interactions, and the fact that these peptides can be expressed in transgenic organisms in a tissue specific manner, may in the future provide a framework for designing genetic-based therapies for neurological disorders.