Uncovering the Biophysical Mechanism of Receptor for Advanced Glycation Endproducts Molecular Function

该奖项将资助爱荷华州立大学的艾米丽·史密斯博士研究使一类膜蛋白发挥功能的化学物种，并详细了解这些蛋白如何在细胞膜中组织和运动。细胞膜中的蛋白质在细胞如何获得关于环境的信息以及对环境做出反应方面起着关键作用。这些蛋白质发挥作用的一种方式是在细胞膜上移动，以促进与其他蛋白质和细胞的相互作用。该项目通过光学光谱和显微镜测量提供信息，将促进对与细胞功能的许多方面相关的两种重要膜蛋白的理解。更广泛的影响活动针对初中生、高中生、本科生和研究生，以实现培养有科学素养的公众的社会目标；增加攻读科学学位的学生数量，包括来自科学领域代表性较低群体的学生；促进强大、多样化和有能力的科学劳动力，以提高美国的全球竞争力。这些活动是与Science Bound合作完成的，Science Bound是一个大学预科项目，旨在增加爱荷华州攻读理科学位的种族多样性学生的数量，当地的美国化学学会种子项目为经济困难的学生提供暑期研究机会。这项工作的首要目标是测量一类被称为模式识别受体(PRRs)的细胞膜蛋白质的聚集、扩散和纳米级组织。这些受体是先天免疫系统的一部分，它识别几种病原体相关的分子模式和损伤相关的分子模式。根据化学定义的配体结合事件，将测量两个PRR的膜内聚集和扩散的分子机制：晚期糖基化终产物受体(RAGE)和Toll样受体4(TLR4)。这两个PRR共享一个配基的子集，并已被证明表现出受体“串扰”，下游蛋白质磷酸化(即，信号)证明。该项目正在使用单粒子跟踪方法来测量TLR4的扩散，并阐明化学表征的配体在影响RAGE和TLR4扩散中的作用。用荧光共振能量转移法检测细胞膜上RAGE和TLR4的结合。这两种受体在细胞膜内相互作用的证据尚未见报道。推测RAGE和TLR4之间的直接相互作用可能是其作用的重要机制，而扩散是这些相互作用的重要调节因素。这项拟议的工作正在为理解PRRs分子功能的分子生物物理方面奠定基础，这将增加关于这些受体下游信号的现有数据。

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Emily Smith from Iowa State University to investigate the chemical species that allow a class of membrane proteins to function, and to develop a detailed understanding of how the proteins organize and move in a cell membrane. Proteins in the cell membrane have a critical role in how cells get information about their surroundings as well as respond to their environment. One way these proteins function is by moving throughout the cell membrane to facilitate interactions with other proteins and cells. This project is providing information, through optical spectroscopy and microscopy measurements that would advance the understanding of two important membrane proteins associated with many aspects of cellular function. Broader impact activities target middle school, high school, undergraduate and graduate students to meet the societal goals of cultivating a scientifically literate public; increasing the number of students pursuing science degrees including students from underrepresented groups in science; and promoting a strong, diverse and capable scientific workforce to increase America's global competitiveness. These activities are being accomplished in partnership with Science Bound, a pre-college program to increase the number of ethnically diverse Iowa students who pursue science degrees, and the local American Chemical Society SEED program that provides summer research opportunities for economically disadvantaged students.The overarching objective of this work is to measure the clustering, diffusion, and nanoscale organization of a class of cell membrane proteins termed pattern recognition receptors (PRRs). These receptors are part of the innate immune system that recognizes several pathogen-associated molecular patterns and damage-associated molecular patterns. The molecular mechanism of clustering and diffusion within the membrane upon chemically-defined ligand binding events will be measured for two PRRs: receptor for advanced glycation endproducts (RAGE) and Toll-like receptor 4 (TLR4). Both PRRs share a subset of ligands, and have been shown to exhibit receptor "cross talk," as evidenced by downstream protein phosphorylation (i.e., signaling). The project is using single particle tracking methods to measure the diffusion of TLR4 and elucidate the role of chemically-characterized ligands in affecting the diffusion of RAGE and TLR4. The RAGE and TLR4 association in the cell membrane is measured by fluorescence resonance energy transfer. Evidence for an association of these two receptors within the membrane has not been reported. It is hypothesized that a direct interaction between RAGE and TLR4 may be an important mechanism of their function, and that diffusion is an important regulator of these interactions. The proposed work is generating a foundation for understanding the molecular biophysical aspects of PRRs' molecular function that will add to the available data on the downstream signaling of these receptors.