QUORUM SENSING AND GENE EXPRESSION IN BACILLUS SUBTILIS

枯草芽孢杆菌中的群体感应和基因表达

• 批准号: 6180251
• 负责人: ALAN D GROSSMAN
• 金额: $ 31.11万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6180251
• 关键词: Bacillus subtilis; bacterial genetics; bacterial proteins; biological signal transduction; cell cycle; gene expression; genetic regulation; genetic regulatory element; molecular cloning; pheromone; protein biosynthesis; protein purification; protein structure function; site directed mutagenesis

DESCRIPTION: Cell-cell signaling controls many processes in the biological world, including development, pathogenesis, mating, and transformation. Signaling processes are often mediated by factors (e. g., hormones, pheromones, neurotransmitters) that are produced by some cells and sensed by others. In bacteria, the ability to sense and respond to high population density is a type of autocrine cell-cell signaling often referred to as quorum sensing. Cells produce extracellular signaling molecules that accumulate as population density increases, and a physiological response occurs at a critical density. The long term goal of this project is to understand how quorum sensing controls gene expression and differentiation in Bacillus subtilis. We will focus on two peptide signaling factors that contribute to quorum sensing in B. subtilis: (1) ComX pheromone, a 10 amino acid peptide with a hydrophobic modification on a tryptophan, and (2) competence and sporulation stimulating factor, CSF, an unmodified pentapeptide. Both signaling molecules accumulate in culture medium as cells grow to high density and contribute to the activation (phosphorylation) of the transcription factor ComA. There are many steps required for signaling by ComX pheromone and CSF, including production of the active signaling molecules and interaction with the appropriate target molecules. CSF is transported into the cell via a the oligopeptide permease Spo0K, a member of the large family of ATP-dependent transporters, whereas ComX pheromone probably interacts with a membrane receptor histidine protein kinase ComP. We plan to address the following questions relating to both ComX pheromone and CSF: What are the determinants of biological activity? What controls production? What are the mechanisms of the response and what are the direct targets of interaction? What genes are activated by the cellular response? Our studies on quorum sensing and gene expression in this relatively simple, experimentally accessible microbe should provide insights into general mechanisms of cell-cell signaling, signal transduction, and regulation.

描述：细胞细胞信号控制生物学中的许多过程 世界，包括发育，发病机理，交配和转变。 信号传导过程通常是由因素介导的（例如，激素， 信息素，神经递质），由某些细胞产生并被感应 其他的。 在细菌中，感知和回应高人口的能力 密度是一种自分泌细胞 - 细胞信号传导，通常称为 法定人数感应。 细胞产生细胞外信号传导分子 随着人口密度的增加而积聚，生理反应 发生在临界密度。 该项目的长期目标是了解法定人数如何感知 控制枯草芽孢杆菌中的基因表达和分化。 我们将 专注于两个有助于群体传感的肽信号传导因子 枯草芽孢杆菌：（1）昏迷的氧气，疏水性的10氨基酸肽 在色氨酸上进行修改，以及（2）刺激能力和孢子形成 因子，CSF，一种未修饰的五肽。 两个信号分子 随着细胞生长至高密度，积聚在培养基中，并有助于 转录因子昏迷的激活（磷酸化）。 那里 是通过昏迷信息素和CSF发出信号所需的许多步骤，包括 产生活性信号分子并与 适当的靶分子。 CSF通过A运输到电池中 寡肽渗透酶SPO0K，大型ATP依赖性家族的成员 转运蛋白，而粘液信息素可能与膜相互作用 受体组氨酸蛋白激酶成分。 我们计划解决以下内容 与昏迷信息素和CSF有关的问题：什么是 生物活性的决定因素？ 什么控制生产？ 什么是 响应的机制以及什么是直接目标 相互作用？ 细胞反应激活了哪些基因？ 我们的 在这个相对简单的研究中，研究法定人数传感和基因表达 实验可访问的微生物应提供一般的见解 细胞 - 细胞信号传导，信号转导和调控的机制。