Stress sensing and processing by bacterial cytoplasmic megacomplexes

项目总结 细菌可以在非常广泛的快速变化的环境中生长和繁殖，适应恶劣的环境 通过感知外部应激源并应用该信息来做出适当的反应。压力- 感知过程与人类健康有关：具有激活应激反应的病原菌较少 容易受到许多抗菌治疗的影响，每年有近10万美国人死于疟疾感染 耐药细菌。事实上，环境中的抗生素是细菌细胞应激源之一。 随时准备好回应。一个持久的挑战是，尽管环境中的分子成分 应激反应系统是众所周知的，但关于这些应激反应的动力学还鲜有发现 随着时间的推移，特别是在单个细胞中。PI将细菌遗传学与微流控技术相结合， 直接观察单细胞谱系在严格控制的环境应激条件下的反应， 揭示了压力-反应系统能够以不同的方式引起几种不同的反应 取决于细胞中存在哪些应力传感器的动力学。这些结果提出了额外的基本原理 问题。位于细胞质中的压力敏感蛋白如何有效地对应激源的开始作出反应？ 都在牢房外吗？应激反应蛋白的哪些分子特征指定了它们的应激源 以及它们所引发的动态反应模式？不同的动态应激反应如何 模式有助于细胞的健康和在不利条件下的生存？拟议的研究旨在解决这些问题 利用枯草芽孢杆菌作为一种高度可处理的环境模型的问题 压力。通过将经典的细菌遗传学、分子技术、荧光显微镜和 微流控技术，这些研究将产生对原理的新的和更机械的理解 控制细菌细胞如何感知环境压力，处理这些感觉输入，并产生有效的 回应。这些结果将对理解应激反应的一般特征具有广泛的意义 横跨许多生物系统。他们还将提供对设计抗菌剂有用的知识 干扰环境压力感知的治疗策略。

PROJECT SUMMARY Bacteria can grow and divide in a remarkably wide range of quickly changing environments, adapting to harsh conditions by sensing external stressors and applying that information to mount an appropriate response. Stress- sensing processes are relevant to human health: pathogenic bacteria with activated stress responses are less susceptible to many antimicrobial treatments, and nearly 100,000 Americans die each year from infections with drug-resistant bacteria. Indeed, environmental antibiotics are one stressor (among many) to which bacterial cells readily respond. A persistent challenge has been that, although the molecular components of the environmental stress response system are well known, little has been discovered about the dynamics of these stress responses over time, particularly in individual cells. The PI has combined bacterial genetics with microfluidic technology to directly observe the responses of single-cell lineages under tightly controlled environmental stress conditions, revealing that the stress-response system is capable of eliciting several distinct responses with different dynamics that depend on which stress sensors are present in the cell. These results raise additional fundamental questions. How do stress-sensing proteins located in the cytoplasm effectively respond to the onset of stressors that are outside the cell? Which molecular features of stress-response proteins specify the stressors they respond to and the dynamic response patterns they instigate? How do different dynamic stress-response patterns contribute to cellular fitness and survival in adverse conditions? The proposed studies tackle these questions by taking advantage of the bacterium Bacillus subtilis as a highly tractable model for environmental stress. By bringing together classical bacterial genetics, molecular techniques, fluorescence microscopy, and microfluidic technology, these studies will yield a new and more mechanistic understanding of the principles that govern how bacterial cells sense environmental stress, process those sensory inputs, and produce an effective response. The results will have broad implications for understanding the general features of stress responses across many biological systems. They will also furnish knowledge that will be useful for devising antimicrobial treatment strategies that interfere with environmental stress sensing.