CELL-CELL SIGNALING AND COMPETENCE IN BACILLUS SUBTILIS

枯草芽孢杆菌的细胞间信号传导和能力

• 批准号: 2189065
• 负责人: ALAN D GROSSMAN
• 金额: $ 23.73万
• 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 1998-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2189065
• 关键词: Bacillus subtilis; bacterial DNA; bacterial genetics; biological signal transduction; cell cell interaction; cystic fibrosis; gene expression; gene mutation; genetic regulation; hemolysin; molecular cloning; multidrug resistance; operon; permease; protein purification; site directed mutagenesis

Cell-cell signaling controls many processes in the biological world, including development, pathogenesis, growth, 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 order to understand regulatory process involving cell-cell signaling, it is essential to identify the signaling molecules, determine how they are produced and sensed, and determine how the signals are transduced to elicit a regulatory response. The long term goal of this project is to understand how cell-cell signaling controls gene expression and differentiation in Bacillus subtilis. B. subtilis produces extracellular signaling molecules that are at least in part oligopeptides that accumulate in culture medium as cells grow to high density. These extracellular signaling peptides stimulate expression of genes needed for the development of genetic competence. Genetic competence in B. subtilis is the natural ability to be transformed by exogenous DNA and is an efficient means of genetic exchange. Our aims are to purify and biochemically characterize the signaling molecules that induce competence gene expression and competence, to characterize how these extracellular signaling molecules are produced, to characterize the mechanisms by which cells sense and respond to these peptide factors, and to determine if the signaling factors involved in competence also affect sporulation. Included in these aims is to characterize the role of the spoOK (opp) operon in the cellular response to peptide signaling factors. Mutations in spoOK cause a defect in competence (and sporulation) and prevent cells from responding to the peptide signaling molecules that stimulate competence gene expression. spoOK encodes an oligopeptide permease that is a member of the large family of ATP-dependent transporters. This family of transport systems includes MDR, involved in multi-drug resistance, CFTR, the cystic fibrosis transmembrane regulator, and Hly, required for hemolysin export in some pathogenic bacteria. Also included in this family of transporters are a variety of permeases from bacteria that mediate uptake of many compounds, including histidine, maltose, phosphate, dipeptides, vitamin B 12, and iron. An important aim of this proposal is to determine how the oligopeptide Permease encoded by spoOK of B. subtilis is involved in controlling expression of competence genes. Our studies on differentiation in this relatively simple, experimentally accessible microbe should provide insights into general mechanisms of cell-cell signaling, signal transduction, and regulation of gene expression and differentiation.

细胞间信号传导控制生物体内的许多过程 世界，包括发育、发病机制、生长、交配和 转变。信号传导过程通常由因素介导 （例如激素、信息素、神经递质） 一些细胞并被其他细胞感知。为了了解监管 涉及细胞间信号传导的过程，因此必须确定 信号分子，确定它们的产生方式和 感测，并确定如何转换信号以引发 监管回应。 该项目的长期目标是了解细胞与细胞之间如何 信号传导控制芽孢杆菌的基因表达和分化 枯草芽孢杆菌。枯草芽孢杆菌产生细胞外信号分子 至少部分是在培养物中积累的寡肽 当细胞生长至高密度时使用培养基。这些细胞外信号传导 肽刺激发育所需基因的表达 的遗传能力。枯草芽孢杆菌的遗传能力是 被外源DNA转化的天然能力，是一种 遗传交换的有效手段。我们的目标是净化和 生化表征诱导的信号分子 能力基因表达和能力，以表征如何 这些细胞外信号分子的产生 表征细胞感知和响应的机制 这些肽因子，并确定信号因子是否 参与能力也影响孢子形成。 这些目标包括描述 spoOK 的角色 (opp) 操纵子在细胞对肽信号传导因子的反应中。 spoOK 突变导致能力（和孢子形成）缺陷 并阻止细胞对肽信号传导做出反应 刺激能力基因表达的分子。 spoOK 编码 寡肽通透酶，是寡肽通透酶大家族的成员 ATP 依赖性转运蛋白。该运输系统系列 包括MDR（涉及多重耐药性）、CFTR（囊性囊肿） 纤维化跨膜调节因子和溶血素所需的 Hly 输出一些致病菌。也被纳入这个大家庭 转运蛋白是介导细菌的多种渗透酶 吸收许多化合物，包括组氨酸、麦芽糖、磷酸盐、 二肽、维生素 B 12 和铁。此举的一个重要目的 提议是确定寡肽渗透酶是如何编码的 B. subtilis 的 spoOK 参与控制表达 能力基因。我们对这种相对差异化的研究 简单的、可通过实验获得的微生物应该提供见解 细胞间信号传导、信号传导的一般机制 基因表达的转导和调节 差异化。