The Role of Odorant Binding Proteins in Anopheline Mosquito Odor Perception

这项建议的工作将研究冈比亚按蚊气味识别的特异性，并将气味刺激与可量化的生理和行为反应相关联。这项工作将整合不同相关领域的互补专业知识，以实现彻底了解冈比亚按蚊的化学感觉系统和化学感觉介导的行为的共同目标。气味识别的特异性很可能编码在气味结合蛋白(OBP)和气味受体(ORs)中。最近的证据表明，气味识别是一个协调的过程，需要OBP和ORS共同贡献的特异性。OBP是嗅觉系统中第一个遇到气味分子的蛋白质，来自我们和其他实验室的数据表明，OBP对冈比亚按蚊的嗅觉反应至关重要。这使得气味结合蛋白成为操纵气味感知的首选目标。因此，体外表达的OBP将用于高通量筛选分析，以鉴定天然配体并推断已知和新鉴定的配体的结合能力。计算机模拟研究使我们能够设计基于突变的实验，以定义与OBP结合口袋相关的氨基酸，并预测具有改进性质的修饰配体。所有体外研究的体内验证将通过使用雌性蚊子的电生理和行为测试来获得，这些雌性蚊子表达正常水平的OBP或由于RNA介导的基因表达下调而导致特定OBP缺乏。从这种多学科方法中获得的知识将导致识别可能干扰雌性蚊子寻找宿主行为的化学物质，减少人类宿主与寄生虫媒介之间的接触。

The work proposed here will investigate the specificity of odorant recognition in the malaria mosquito Anopheles gambiae and correlate odor stimuli with quantifiable physiological and behavioral responses. This work will integrate complementary expertise in various relevant fields toward the common goal of thoroughly understanding the chemosensory system and chemosensory-mediated behavior of A. gambiae. Odor recognition specificity is very likely encoded in both odorant binding proteins (OBPs) and odorant receptors (ORs). Recent evidence suggests that odor recognition is a coordinated process that requires the combined specificities contributed by OBPs and ORs. OBPs are the first proteins of the olfactory system to encounter odor molecules, and data from our and other laboratories demonstrate that OBPs are critical for the olfactory response in A. gambiae. This makes the odorant binding proteins a preferred target for manipulating odor perception. Thus, in vitro expressed OBPs will be used in high-throughput screening assays to identify natural ligands and deduce binding capacities for known and newly identified ligands. Computer modeling studies allow us to design mutagenesis-based experiments to define amino acids associated with the OBP binding pocket and predict modified ligands with improved properties. In vivo validation of all in vitro studies will be obtained through electrophysiological and behavioral assays employing female mosquitoes that express normal levels of OBPs or are deficient in a specific OBP as a result of RNAimediated gene expression knockdown. Knowledge gained from this multi-disciplinary approach will lead to the identification of chemicals that can interfere with host seeking behavior by female mosquitoes, reducing the incidence of contact between the human host and the parasite vector.