CELL-CELL SIGNALING AND COMPETENCE IN BACILLUS SUBTILIS

细胞-细胞信号控制着生物体内的许多过程。 世界，包括发育、发病机制、生长、交配和 转型。信号传递过程往往受各种因素的影响 (例如，激素、信息素、神经递质)由 一些细胞并被其他细胞感觉到。为了了解监管 涉及细胞-细胞信号传递的过程，识别 信号分子，决定它们是如何产生的，以及 并确定信号如何被传递以引发 监管回应。 这个项目的长期目标是了解细胞-细胞如何 信号转导控制芽孢杆菌的基因表达和分化 枯草杆菌。枯草杆菌产生胞外信号分子 至少部分是在培养中积累的寡肽 当细胞生长到高密度时，进行培养。这些细胞外信号 多肽刺激发育所需基因的表达 遗传能力。枯草杆菌的遗传能力是 能够被外源DNA转化的天然能力，是一种 基因交换的有效手段。我们的目标是净化和 从生物化学的角度描述信号分子诱导 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是为了 描述细胞感知和响应的机制 这些多肽因子，并确定信号因子是否 参与能力也会影响产孢量。 包括在这些目标中的是描述幽灵的角色 (OPP)操纵子在细胞对肽信号因子的反应中。 SPOCK基因突变导致能力缺陷(和产孢量) 并阻止细胞对多肽信号做出反应 刺激能力基因表达的分子。SPOCK编码 一种低聚肽渗透酶，是大家族中的一员 依赖于ATP的转运蛋白。这一系列的运输系统 包括多药耐药，参与多药耐药，CFTR，囊性 溶血素所需的纤维化跨膜调节因子和HLY 出口一些病原菌。也包括在这个家族中 转运蛋白是由细菌介导的各种渗透性物质。 摄取许多化合物，包括组氨酸、麦芽糖、磷酸盐、 二肽、维生素B12和铁。这样做的一个重要目的是 建议确定寡肽渗透酶是如何编码的 枯草杆菌spok参与调控枯草杆菌的表达 能力基因。我们对这一相对的分化的研究 简单的、可通过实验获得的微生物应该提供见解 细胞-细胞信号的一般机制，信号 基因表达的转导和调节 差异化。

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.