Molecular Biology of the Odorant Receptors

描述（由申请人提供）：人类疾病的昆虫媒介每年感染数亿人致命的传染病，包括疟疾、登革热和黄热病以及西尼罗河脑炎。昆虫是通过特定的感官线索被吸引到人类宿主身上的，其中嗅觉线索起着主导作用。该提案的长期目标是了解嗅觉系统允许昆虫在人类宿主上磨练的机制。这些知识可以转化为一类新的化学试剂，作用于昆虫的嗅觉系统，以中断媒介昆虫的寄主寻找行为。响应PA-05-154，这个特定项目的总体目标是增加对昆虫中介导气味识别的气味受体（OR）的分子结构和功能的理解。在初步研究中，我们已经记录了OR 83 b的独特伴侣辅助受体功能。OR 83 b在体内大多数嗅觉感觉神经元中共表达并与常规OR形成OR/OR 83 b异二聚体，并且对于发生气味转导的纤毛树突中的OR的靶向和维持是必需的。这些初步研究提出了OR/OR 83 b复合物对昆虫嗅觉功能至关重要的假设。为了验证这一假设，提出了3个具体目标：1）鉴定介导OR 83 b靶向嗅觉纤毛的蛋白质结构域; 2）定义介导异聚OR/OR 83 b复合物形成的蛋白质结构域; 3）表征调节OR/OR 83 b复合物的翻译后修饰。研究设计涉及OR 83 b的靶向诱变，以揭示运输、OR/OR 83 b异聚化和翻译后修饰所必需的基序。所使用的方法是采用电生理学、成像、细胞生物学、生物化学和行为学技术在体内和体外对果蝇OR功能进行表型分析。对昆虫OR功能的分子理解可以帮助设计新型化学试剂，其选择性地破坏昆虫OR，从而中断昆虫疾病媒介如蚊子的宿主寻找行为。这一建议的健康相关性在于，此类化学制剂可能会在未来减少病媒昆虫传播的传染病。

DESCRIPTION (provided by applicant): 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, 3 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.