Molecular basis of pyrethroid resistance

描述（由申请方提供）：本研究的长期目标是了解昆虫杀虫剂抗性的分子基础。蟑螂、蚊虫等害虫作为人类病原体的携带者，是人类健康的主要威胁。此外，蟑螂是室内过敏原的主要来源，也是急性哮喘的原因。大量使用拟除虫菊酯类杀虫剂来控制这些害虫，导致抗药性害虫种群的快速选择。抗药性的发展是有效控制害虫的主要障碍。钠通道蛋白（拟除虫菊酯的靶标）的突变是拟除虫菊酯抗性的主要原因，导致对所有拟除虫菊酯杀虫剂的交叉抗性。对天然存在的拟除虫菊酯耐药性相关钠通道突变和选择性剪接变体的分析表明，钠通道跨膜螺旋4（S4）和6（S6）在拟除虫菊酯耐药性中发挥关键作用。然而，这些突变如何赋予拟除虫菊酯抗性尚不清楚。在本研究中要检查的中心工作假设是拟除虫菊酯抗性突变影响拟除虫菊酯与S6中假定位点的结合，和/或在通道失活期间促进S4/S6向静息状态的移动，这被拟除虫菊酯抑制。将使用分子遗传学、电生理学和药理学方法的组合，通过分析天然和实验室产生的突变，在机制水平上了解拟除虫菊酯的作用/抗性。具体目标是：1.检测拟除虫菊酯抗性突变对拟除虫菊酯与蟑螂钠通道结合的影响.拟除虫菊酯抗性突变对蟑螂钠通道门控动力学影响的表征。3.第4和第6跨膜片段在拟除虫菊酯抗性中的作用的综合检查。

DESCRIPTION (provided by the applicant): The long-term goal of this research is to understand the molecular basis of insecticide resistance in insects. As carriers of human pathogens, insect pests, such as cockroaches and mosquitoes, are major threats to human health. In addition, cockroaches are a major source of indoor allergens and a cause of acute asthma. The intensive use of pyrethroid insecticides to control these pests has led to rapid selection of resistant pest populations. The development of resistance presents a major obstacle to the effective control of insect pests. Mutations in the sodium channel protein, the target of pyrethroids, are a major cause of pyrethroid resistance, resulting in cross-resistance to all pyrethroid insecticides. Analysis of naturally occurring pyrethroid resistance-associated sodium channel mutations and alternative-splicing variants suggests a critical role of sodium channel trans-membrane helixes 4 (S4) and 6 (S6) in pyrethroid resistance. However, how these mutations confer pyrethroid resistance is not understood. The central working hypothesis to be examined in this research is that pyrethroid-resistance mutations either affect pyrethroid binding to a putative site in S6, and/or facilitate the movement of S4/S6 to the resting state during channel deactivation, which is inhibited by pyrethroids. A combination of molecular genetic, electrophysiological and pharmacological approaches will be used to understand pyrethroid action/resistance at the mechanistic level by analyzing both natural and laboratory-created mutations. The specific aims are:1. Examination of the effect of pyrethroid resistance mutations on pyrethroid binding to cockroach sodium channels.2. Characterization of the effect of pyrethroid resistance mutations on cockroach sodium channel gating kinetics. 3. Comprehensive examination of the role of the 4th and 6th trans-membrane segments in pyrethroid resistance.