Regulation of the Heat Shock Response in E. Coli

大肠杆菌热激反应的调节

• 批准号: 8610923
• 负责人: CAROL Anne GROSS
• 金额: $ 37.86万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8610923
• 关键词: Area; Bacteria; Binding; Binding Proteins; Binding Sites; Biological Assay; Biomass; Cell Wall; Cell membrane; Cells; Cleaved cell; Communication; Complex; Cytoplasm; Defect; Disease; Environment; Escherichia coli; Event; Failure; Gene Expression Process; Genes; Genetic Transcription; Genomics; Goals; Gram-Negative Bacteria; Grant; Growth; Heat-Shock Response; Heating; Homeostasis; In Vitro; Investigation; Life; Link; Lipopolysaccharides; Lipoprotein Binding; Lipoproteins; Logic; Longitudinal Studies; Mediating; Membrane; Membrane Proteins; Methods; Modeling; Molecular Chaperones; Monitor; Nucleotides; Oceans; Oral; Organism; Pattern; Peptide Hydrolases; Plants; Process; Prokaryotic Cells; Property; Proteins; Quality Control; Regulation; Reporting; Resolution; Ribosomes; Shock; Signal Recognition Particle; Signal Transduction; Stress; System; Techniques; Temperature; Testing; Translation Initiation; Translations; antitermination; biological adaptation to stress; cold temperature; combinatorial; coping; design; experience; fighting; in vivo; knowledge base; mRNA Transcript Degradation; macromolecule; new technology; periplasm; porin; protein expression; protein folding; public health relevance; reconstitution; research study; residence; response; tool; trafficking; transmission process

DESCRIPTION (provided by applicant): Bacteria live in diverse and variable environments and constitute about half of the world's biomass. Free-living bacteria must adapt to daily and seasonal temperature changes; those living in host organisms experience temperature change during their transmission cycles, which usually include transient residence in the external environment (e.g. fecal-oral transmission). On the other hand, 90% of the oceans are ¿ 5¿C, adaptations that enable bacterial growth in the cold are essential for many bacteria. In toto, adaptation to temperature change is one of the most pervasive challenges facing bacteria. We study the stress responses that enable adaptation to both heat and cold. Our long-term studies of thermal adaptation have consistently set new paradigms. We identified and are dissecting the two homeostatic circuits that monitor protein folding in all compartments of the bacterial cell. ¿3 monitors both cytoplasmic and inner membrane (IM) protein folding status, whereas ¿E monitors protein-folding stress in the envelope, and maintains outer membrane (OM) homeostasis, serving as a paradigm for intercompartmental communication in prokaryotes. Thus, we have identified and are studying the central protein quality control circuitry of gram-negative bacteria It is the underlying mechanisms and principles of process coordination that is the focus of our new studies. We will determine how the circuitry controlling s32 integrates protein folding status signals from both the IM and cytoplasmic compartment. Likewise, we will investigate how the circuitry controlling ¿32 integrates three signals of OM homeostasis. Higher order process integration is poorly understood in any organism. Importantly, the existing knowledge base and available tools permit us to carry out an incisive investigation of this critical issue. Additionaly, these studies may provide the first example of how unicellular organisms sense and integrate signals from their outer membranes or cell walls to maintain cellular integrity. In contrast to hea shock responses that are mediated by transcriptional homeostatic circuits, cold adaptation is centered around how the cell responds to critical failures in translation. This response is poorly understood, despite its universality. As cold shock perturbs central gene expression processes, it may expose critical, unanticipated interconnections between these processes. We study the cold shock response using a revolutionary new technology that enables us to detect instantaneous changes in translation at the genomic level with great sensitivity and near-nucleotide resolution. Our initial results modifying this technique for the bacterial CSR not only immediately identified the temporal pattern of the response but also revealed unexpected changes in global translational pausing and termination that were inaccessible by previous methods, thereby increasing the known repertoire of translational modulation. We will continue to dissect the process interconnections we have identified and also perform comparable studies in B. subtilis, to uncover common and unique strategies to this universal stress.

描述（由申请人提供）：细菌生活在多样化和可变的环境中，约占世界生物量的一半。自由生活的细菌必须适应每日和季节性的温度变化；那些生活在宿主生物中的细菌在其传播周期中会经历温度变化，这通常包括在外部环境中的短暂停留（例如粪便-口腔传播）。另一方面，90%的海洋都是摄氏温度，使细菌能够在寒冷中生长的适应性对许多细菌来说是必不可少的。总的来说，适应温度变化是细菌面临的最普遍的挑战之一。我们研究能够适应热和冷的应激反应。我们对热适应的长期研究一直在建立新的范例。我们确定并正在解剖两个监测细菌细胞所有隔室中蛋白质折叠的稳态电路。¿3监测细胞质和内膜（IM）蛋白质折叠状态，而¿E监测包膜中的蛋白质折叠压力，并维持外膜（OM）稳态，作为原核生物室间通信的范例。因此，我们已经确定并正在研究革兰氏阴性菌的中心蛋白质量控制电路，这是过程协调的潜在机制和原则，是我们新研究的重点。我们将确定控制s32的电路如何整合来自IM和细胞质室的蛋白质折叠状态信号。同样，我们将研究控制¿32的电路如何集成OM稳态的三个信号。在任何生物体中，人们对高阶过程整合都知之甚少。重要的是，现有的知识库和可用的工具使我们能够对这一关键问题进行深入的调查。此外，这些研究可能提供了单细胞生物如何感知和整合来自外膜或细胞壁的信号以维持细胞完整性的第一个例子。与由转录稳态回路介导的休克反应相反，冷适应主要围绕细胞如何对翻译中的关键失败作出反应。尽管这种反应具有普遍性，但人们对其了解甚少。由于冷休克扰乱了中心基因表达过程，它可能暴露出这些过程之间关键的、意想不到的相互联系。我们使用一种革命性的新技术研究冷休克反应，使我们能够以极高的灵敏度和近核苷酸分辨率检测基因组水平上翻译的瞬时变化。我们的初步结果修改了细菌CSR的技术，不仅立即确定了反应的时间模式，而且揭示了全球翻译暂停和终止的意想不到的变化，这是以前的方法无法实现的，从而增加了已知的翻译调节库。我们将继续剖析我们已经确定的过程相互联系，并在枯草芽孢杆菌中进行可比研究，以揭示这种普遍压力的共同和独特策略。