Molecular Biology of the Odorant Receptors

人类疾病的昆虫媒介每年感染数亿人，具有致命的传染性 疾病，包括疟疾、登革热和黄热病以及西尼罗河脑炎。昆虫被吸引到 人类依靠特定的感官线索，其中嗅觉线索起主导作用。《远大前程》 这项建议的目的是了解嗅觉系统允许昆虫 来磨练人类的宿主。这样的知识可以转化为一类新的化学试剂 在昆虫嗅觉系统上中断媒介昆虫寻找寄主的行为。响应PA-05-154， 这个具体项目的总体目标是增加对分子结构和功能的了解 在昆虫中介导气味识别的气味受体(ORs)。在初步研究中，我们有 记录了OR83b独特的伴随共受体功能。OR83b是共同表达的，形式为OR/ OR83b与常规ORs的异源二聚体在大多数活体嗅觉神经元中是必需的 气味转导的纤毛树突中ORs的靶向和维持。这些 初步研究表明，OR/OR83b复合体对昆虫的嗅觉是必不可少的 功能。为了验证这一假设，我们提出了三个具体目标： 1)鉴定介导OR83b靶向嗅觉纤毛的蛋白质结构域 2)定义介导形成异构体OR/OR83b复合体的蛋白质结构域 3)表征调节OR/OR83b复合体的翻译后修饰 研究设计涉及对OR83b进行有针对性的突变，以揭示贩运所必需的基序， OR/OR83b异构化和翻译后修饰。所使用的方法是表型的。 果蝇体内外功能的电生理、成像、细胞分析 生物、生化和行为技术。对昆虫OR功能的分子理解可能会 帮助设计新的化学试剂，选择性地扰乱昆虫的ORs，从而干扰宿主- 寻找蚊子等昆虫病媒的行为。这项建议与健康相关的是 这种化学制剂可能会在未来减少媒介昆虫传播传染病的作用。

Insect vectors of human disease infect hundreds of millions of individuals annually with deadly infectious diseases, including Malaria, Dengue and Yellow Fever, and West Nile Encephalitis. Insects are attracted to human hosts by specific sensory cues, with olfactory cues playing a dominant role. The Broad," Long-Term Objectives of this proposal are to understand the mechanisms by which the olfactory system allows insects to hone in on human hosts. Such knowledge could be translated to a new class of chemical agents that act on the insect olfactory system to interrupt vector insect host-seeking behavior. Responsive to PA-05-154, the overall goal of this specific project is to increase understanding of the molecular structure and function of the odorant receptors (ORs) that mediate odor recognition in insects. In preliminary studies, we have documented a unique chaperoning co-receptor function for OR83b. OR83b is co-expressed and forms OR/ OR83b heterodimers with conventional ORs in most olfactory sensory neurons in vivo and is necessary for the targeting and maintenance of ORs in ciliated dendrites where odor transduction occurs. These preliminary studies have led to the hypothesis that the OR/OR83b complex is essential for insect olfactory function. To test this hypothesis, three Specific Aims are proposed: 1) Identify protein domains that mediate OR83b targeting to olfactory cilia 2) Define protein domains that mediate the formation of heteromeric OR/OR83b complexes 3) Characterize post-translational modifications that modulate the OR/OR83b complex The Research Design involves targeted mutagenesis of OR83b to uncover motifs necessary for trafficking, OR/OR83b heteromerization, and post-translational modifications. The Methods used are phenotypic analysis of Drosophila OR function in vivo and in vitro employing electrophysiological, imaging, cell biological, biochemical, and behavioral techniques. A molecular understanding of insect OR function may aid in the design of novel chemical agents that selectively disrupt insect ORs and thus interrupt host- seeking behaviors of insect disease vectors such as mosquitoes. The Health-Relatedness of this proposal is that such chemical agents may act to reduce infectious disease transmission by vector insects in the future.