CAREER: Elucidating the Mechanism and Role of Globin-Coupled Sensor Signaling

化学部生命过程化学项目颁发的这一职业奖将支持埃默里大学的Emily Weinert博士确定信号转导机制和珠蛋白偶联传感器信号在不同细菌中的作用。细菌形成被称为生物膜的三维群落，以响应环境信号，保护细菌免受捕食和环境压力。为了了解细菌如何感知和响应环境，需要详细了解影响细菌生长、新陈代谢和生物膜形成的环境信号、蛋白质和途径。这项研究的结果将阐明氧浓度在控制细菌表型中的作用，确定氧感应的分子机制，并可能突出改变氧依赖信号的新方法。更广泛的影响来自教师-学者活动，这些活动被纳入研究计划。这些活动将激发学生对科学过程的兴趣，并鼓励学生追求并保持在科学领域的职业生涯。建议的活动包括1)指导高中生、本科生和研究生，2)开发本科化学生物学课程，向学生介绍主要文献和补助金的撰写，以及3)在埃默里建立两个新的组织，一个是促进女性在科学中的研究生分会，一个是本科生化学研究荣誉学会。这项研究项目的中心是确定信号转导的机制和珠蛋白偶联传感器信号在不同细菌中的作用。珠蛋白偶联传感器(GCS)是含有血红素的信号蛋白，被认为是体内的氧气传感器。一些GCS被预测包含二鸟苷环化酶结构域，它催化c-di-GMP的产生，c-di-GMP是一种细菌第二信使，调节生物膜的形成。为了了解在环境中发现的复杂的、不同种类的生物膜，必须在分子和生物水平上了解调节生物膜形成的因素，如气体环境。虽然在许多细菌的基因组中已经发现了可能的氧敏感GCSs，但对蛋白质内的信号转导机制、中间结构域的作用以及氧信号的下游效应还知之甚少。因此，了解细菌感知氧气水平的机制将有助于阐明细菌如何对不断变化的环境条件做出反应，并有可能重新设计这些途径。本研究的目的是1)研究不同细菌不同中间结构域长度的GCS的配体依赖活性，2)确定中间结构域的信号转导机制和作用，3)表征体内受GCS信号控制的相互作用伙伴和下游表型。通过在分子水平上了解不同氧气水平对细菌表型的影响，将有可能阐明GCSs在各种生物体中依赖氧气的生物膜形成和代谢变化中的作用。该项目由分子和细胞生物科学分部的系统和合成生物学集群共同资助

This CAREER award from the Chemistry of Life Processes Program in the Division of Chemistry will support the work of Dr. Emily Weinert at Emory University to determine the mechanism of signal transduction and the role of globin-coupled sensor signaling in diverse bacteria. Bacteria form three-dimensional communities, termed biofilms, in response to environmental signals, which protect the bacteria from predation and environmental stress. To understand how bacteria sense and respond to their environment, a detailed knowledge of the environmental signals, proteins, and pathways that affect bacterial growth, metabolism, and biofilm formation is required. The results from the proposed research will elucidate the role of oxygen concentration in controlling bacterial phenotypes, determine the molecular mechanism of oxygen sensing, and potentially highlight novel methods to alter oxygen-dependent signaling. The broader impacts emanate from teacher-scholar activities, which are integrated into the research plan. These activities will pique student interest in the scientific process and encourage students to pursue and remain in careers within the sciences. Proposed activities include 1) mentoring of high school, undergraduate, and graduate students, 2) development of an undergraduate chemical biology class to introduce students to the primary literature and grant writing, and 3) establishment of two new organizations at Emory, a graduate chapter of Advancing Women in Science and an undergraduate Chemistry research honor society.This research project is centered on determining the mechanism of signal transduction and the role of globin-coupled sensor signaling in diverse bacteria. Globin-coupled sensors (GCS) are heme-containing signaling proteins proposed to serve as oxygen sensors in vivo. A number of GCSs are predicted to contain diguanylate cyclase domains, which catalyze production of c-di-GMP, a bacterial second messenger that regulates biofilm formation. To understand complex, heterogeneous biofilms found in the environment, the factors regulating biofilm formation, such as gaseous environment, must be understood at both the molecular and organismal level. Although putative oxygen-sensing GCSs have been identified in the genomes of many bacteria, the mechanism of signal transduction within the protein, the role of the middle domain, and the downstream effects of oxygen signaling are poorly understood. Therefore, understanding the mechanisms by which bacteria sense oxygen levels will help to illuminate how bacteria respond to changing environmental conditions and potentially allow for reengineering of these pathways. The aims of this research proposal are to 1) investigate the ligand-dependent activity of GCSs with varying middle domain lengths from diverse bacteria, 2) identify the mechanism of signal transduction and role of the middle domain, and 3) characterize interacting partners and downstream phenotypes controlled by GCS signaling in vivo. By understanding the effect of varying oxygen levels on bacterial phenotypes at the molecular level, it will be possible to elucidate the role of GCSs in oxygen-dependent biofilm formation and metabolic changes in a wide variety of organisms.This project is co-funded by the Systems and Synthetic Biology Cluster in the Division of Molecular and Cellular Biosciences