COORDINATE REGULATION OF BACTERIAL VIRULENCE FACTORS

我们将研究协调调节的遗传基础， 细菌毒力决定因子利用三个实验 微生物-霍乱弧菌、百日咳博德特氏菌和土杆菌 杆菌 我们的目标是确定 每种生物体中的毒力基因组都伴随着 表达或压抑。 实现这一目标的实验方法 将是类似的每一个遗传系统检查，并将 包括以下步骤：1.营养和物理分析 调节毒力的参数; 2. TnphoA基因的分离 由这些参数调节的融合体; 3.确认 预期的毒力调节基因控制着 这些TnphoA基因融合体的表达; 4.识别 选择的TnphoA融合体的启动子和控制位点， 标准方法（即，DNA测序、S1和引物延伸 mRNA定位、缺失、化学和阿托伐他汀指导 诱变和蛋白质-DNA结合研究）。 霍乱弧菌 我们将扩展我们对toxR协调监管的分析， 包括其他可能ToxR调节毒力的系统 特性（即，表达皮利、外膜蛋白、神经氨酸苷酶， 蛋白酶、溶血和运动性）。 在B。百日咳，我们将 继续分析vir的正负坐标 调控，包括启动子结构和遗传分析， 调制响应。 霍乱弧菌和E.我们将 研究铁的调节反应，重点是滋贺的基因， 如毒素1型（sltAB）以及其它毒力因子（例如， 溶血素、侵入性和粘附因子）可能 由每种动物的铁反应皮毛基因产物控制， 有机体 在可能的情况下，我们会将收集的数据应用于 开发和改进霍乱和百日咳疫苗。

We will study the genetic basis for the coordinate regulation of bacterial virulence determinants utilizing three experimental organisms-Vibrio cholerae, Bordetella pertussia and Escherchia coli. Our goal is to define the molecular mechanism by which groups of virulence genes in each organism are concomitantly expressed or repressed. The experimental approach to this goal will be similar for each of the genetic systems examined and will include the following steps: 1. Analysis of nutritional and physical parameters that regulate virulence; 2. Isolation of TnphoA gene fusions that are regulated by these parameters; 3. Confirmation that the expected virulence regulatory gene controls the expression of these TnphoA gene fusions; 4. Identification of the promoter and control sites for selected TnphoA fusions by standard methods (i.e., DNA sequencing, S1 and primer extention mRNA mapping, deletion, chemical, and oligonucleotide-directed mutagenesis, and protein-DNA binding studies). For V. cholerae we will expand our analysis of the toxR coordinate regulatory system to include other possible ToxR-regulated virulence properties (i.e., expression of pili, OMPs, neuraminadase, protease, hemolysis, and motility). In B. pertussis we will continue our analysis of vir positive and negative coordinate regulation to include promoter structure and genetic analysis of the modulation response. For V. cholerae and E. coli we will study iron-regulatory responses focusing on the genes for Shiga- like toxin type 1 (sltAB) as well as other virulence factors (e.g., hemolysin, invasive properties, and adherence factors) potentially controlled by the iron-responsive fur gene products of each organism. Where possible, we will apply data we collect to the development and improvement of cholera and pertussis vaccines.