Chemical Tools to Probe the Activation of Bacterial Signaling

细菌可以感知并对周围的世界做出反应。例如，处于恶劣环境中的微生物会激活防御机制。然而，细菌如何能够区分它们遇到的许多化学刺激并做出相应的反应，目前还不是很清楚。明尼苏达大学的Carlson和Goodpaster教授使用化学合成和生化方法来了解细菌使用的反应途径，以及它们如何根据各种环境条件定制反应，如高温、低营养或抗生素等化合物的存在。这一知识最终使我们能够对细菌的行为进行有利的控制，包括生产生物燃料或可用作药物的天然产品。一系列教育活动向学生，特别是来自低社会经济群体和不同背景的女孩介绍微生物在我们生活中扮演的角色。这些努力包括多年来与同一群女孩和年轻女性进行互动，鼓励她们在未来的职业生涯中将自己视为科学家。该项目还为研究生提供了从六岁开始指导和教授学生的机会，并制作了广泛传播的材料，使其他人能够向年轻学生传授细菌及其对我们生活的许多功能，无论是好的还是坏的。通过这一奖项，生命过程化学计划资助明尼苏达大学的Carlson和Goodpaster教授研究微生物如何将它们生存的复杂环境转化为生存和茁壮成长所需的行动。对这种能力至关重要的是双组分系统(TCSs)，它由组氨酸激酶和反应调节蛋白对组成。单个生物体拥有数十到数百个单独的TCS，每个TCS对一个或少数化学信号具有高度的敏感性和选择性。每一种化学信息都被转化为特定的细菌活动，包括生长、运动、天然产物的生物合成和致病机理。虽然已经研究了许多单独的TCS，但目前的方法不能对其中许多TCS被诱导的条件进行全局评估，不能表征TCS信号转导与表型结果之间的关系，或多个TCS之间的反应调节。要更深入地了解TCS介导的信号转导，需要：1)分子的合成和评估，以了解如何将含磷分子内化到细菌中；2)开发化学蛋白质组学方法，将TCS与其刺激分子(S)配对，并在活细胞中定位环境应激源对HK的激活。首要目标是定义一般性应激反应所需的一套TCS，以及那些特定于刺激的TCS。这些信息促进了对细菌如何能够利用其相对有限的基因组来协调对几乎无限的刺激的反应的更深入的理解。这个目标与NSF十大想法之一--理解生活规则--是一致的。阐明了一套预测生物体的可观察特征及其表型的规则，因为它与TCS的作用有关。与这些研究目标相辅相成的是教育和推广活动，重点是来自低社会经济群体和不同背景的女孩，向她们介绍微生物在我们日常生活中扮演的角色。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Bacteria can sense and respond to the world around them. For example, a microbe in a hostile environment activates mechanisms of defense. However, it is not well understood how bacteria are able to differentiate between the many chemical stimuli that they encounter and respond accordingly. Professors Carlson and Goodpaster of the University of Minnesota uses chemical synthesis and biochemical methods to gain an understanding of the response pathways that bacteria use and how their responses are customized to a variety of environmental conditions, such as high temperature, low nutrients, or the presence of chemical compounds, such as antibiotics. This knowledge ultimately enables us to control the behaviors of bacteria to our advantage, including for the production of biofuels or natural products that can be used as drugs. A collection of educational activities introduces students, especially girls from low socioeconomic groups and diverse backgrounds, to the roles that microbes play in our lives. These efforts include interactions with the same cohort of girls and young women over multiple years, encouraging them to see themselves as scientists in their future careers. This program also provides opportunities for graduate students to mentor and teach students starting from age six and generates materials that are broadly disseminated to enable others to teach young students about bacteria and their many functions on our lives, both bad and good. With this award, the Chemistry of Life Processes Program is funding Professors Carlson and Goodpaster at the University of Minnesota to study how microbes translate the complex environment in which they live into the actions required to survive and thrive. Essential to this capability are the two-component system (TCSs), which consist of a histidine kinase and response regulator protein pair. A single organism possesses tens to hundreds of individual TCSs, each reacting with high sensitivity and selectivity to one or a small number of chemical signals. Each chemical message is converted into a defined bacterial action, ranging from growth, motility, biosynthesis of natural products, and pathogenesis. Although numerous individual TCSs have been studied, current methodologies do not enable global assessment of the conditions under which many of them are induced, characterization of the relationship between TCS signal transduction and phenotypic results, or the regulation of response between multiple TCSs. A deeper understanding of TCS-mediated signaling is achieved by: 1) Synthesis and evaluation of molecules to develop an understanding of how to internalize phosphate-containing molecules into bacteria, and 2) Develop chemical proteomics methodologies to pair TCSs with their stimulating molecule(s) and to globally map HK activation by environmental stressors in live cells. The overarching goal is to define the suite of TCSs that are required for a generic stress response and those that are stimulus-specific. This information promotes a deeper understanding of how bacteria are able to utilize their relatively limited genome to orchestrate response to nearly limitless stimuli. This goal is aligned with one of the NSF 10 Big Ideas, Understanding the Rules of Life. A set of rules that predict an organism's observable characteristics and its phenotype, as it relates to the roles of the TCSs, is elucidated. These research goals are complemented with educational and outreach activities, focused on girls from low socioeconomic groups and diverse backgrounds, that introduce them to the roles that microbes play in our everyday lives.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.