Elucidating the structural determinants of odor specificity in insect olfactory receptors

项目摘要 嗅觉为动物提供了有关它们所处环境的重要信息。在分子水平上， 嗅觉刺激由成千上万个不同的小分子组成，这些小分子没有其他共同的化学特征 而不是反复无常。为了应对这种多样性，昆虫和哺乳动物都进化出了大家族 嗅觉受体(OR)以一种组合的方式工作，由此一些受体被广泛地激活 许多不同的香料和其他香料都精致地调节到一种特定的化合物中。分子机制 赋予ORs如此多样化的配体结合特性的原因仍不清楚，主要是因为分离和 ORs的结构表征一直是一个长达数十年的技术挑战。使用低温电子 在显微镜下，我最近确定了第一个与气味结合的昆虫的原子分辨结构。通过 确定具有广泛和特定配体结合特性的额外昆虫ORs的结构， 拟议的研究项目将阐明气味检测和识别的分子机制。 为此，K99指导阶段(目标1)将揭示两个原始昆虫ORO的原子结构 不同的配体特性自由结合，并与多个气味配体形成络合物，使分子发光 广泛的或特定的气味选择性的决定因素。接下来，R00独立阶段(目标2)将专注于 来自参与人类寻找宿主的携带疾病的蚊子的OR。这些OR显示的是小的 极大地影响它们检测人类气味的能力的多态。关于原子结构的阐明 这些与人类挥发物结合的蚊子OR将阐明使蚊子能够 侦测并捕食人类。总而言之，这项研究计划将为人们提供对正常情况的基本洞察 嗅觉信息的感觉加工功能。此外，由于昆虫ORO关键地参与了 这项工作将为人类寻找宿主，促进虫媒疾病的传播提供基础 开发新型驱虫剂，以遏制疟疾、寨卡病毒和登革热等疾病。 拟议的发展计划通过以下方式补充我在结构生物学和生物物理学方面的培训 果蝇受体-配体相互作用的计算机模拟和体内分析。在结束时， 导师阶段，我将配备必要的工具，进行全面的结构和功能 病媒昆虫气味检测与识别的研究。为了实现这些目标，我将采取 利用洛克菲勒大学的广泛资源，Vanessa Ruta博士和 任命一个咨询委员会，为项目和职业生涯的关键方面提供专门知识 发展。此外，有了MOSAIC/UE5网络的支持和资源，我将扩展我的 指导和领导技能，以成功过渡到独立的职位，同时继续我的 正在努力加强生物医学劳动力的多样性。

Project Summary The sense of smell provides animals with vital information about their environment. At the molecular level, olfactory stimuli consist of thousands of distinct small molecules that share no common chemical feature other than being volatile. To contend with this diversity, insects and mammals alike have evolved large families of olfactory receptors (ORs) that operate in a combinatorial way, whereby some receptors are broadly activated by many different odorants and others are exquisitely tuned to a specific compound. The molecular mechanisms that endow ORs with such diverse ligand-binding properties remain unknown, largely because the isolation and structural characterization of ORs has been a decades-long technological challenge. Using cryo-electron microscopy, I recently determined the first atomic-resolution structure of an insect OR bound to an odor. By determining the structures of additional insect ORs with broad and specific ligand-binding properties, the proposed research project will elucidate the molecular mechanism of odor detection and discrimination. To this end, the K99 mentored phase (Aim 1) will reveal the atomic structures of two primitive insect ORs with different ligand specificities unbound and in complex with multiple odor ligands, shedding light on the molecular determinants that underlie broad or specific odor selectivity. Next, the R00 independent phase (Aim 2) will focus on ORs from disease-carrying mosquitoes that participate in human host-seeking. These ORs exhibit small polymorphisms that drastically affect their ability to detect human odors. Elucidation of the atomic structure of these mosquito ORs bound to human volatiles will illuminate the molecular properties that enable mosquitoes to detect and prey on humans. Together, this research program will lend fundamental insight into the normal function of sensory processing of olfactory information. Additionally, as insect ORs are critically involved in human host-seeking that facilitates the spread of insect-borne diseases, this work will provide a foundation for the development of novel insect repellents that could curb diseases such as malaria, Zika, and dengue fever. The proposed development plan complements my training in structural biology and biophysics with computational modeling of receptor-ligand interactions and in vivo assays in Drosophila. At the end of the mentored phase, I will be equipped with the necessary tools to conduct comprehensive structural and functional studies of odor detection and discrimination by insect vectors of disease. To achieve these goals, I will take advantage of the extensive resources of the Rockefeller University, the mentorship of Dr. Vanessa Ruta and the appointment of an Advisory Committee that will lend expertise in key aspects of the project and career development. Additionally, with the support and resources from the MOSAIC/UE5 network I will expand my mentorship and leadership skills to successfully transition to an independent position while continuing my ongoing efforts to enhance diversity in the biomedical workforce.