GLOBAL REGULATION OF VIRULENCE FACTOR IN BORDETELLA PERTUSSIS

百日咳杆菌的vir基因座是一个中枢调控基因，它 控制百日咳毒素、FHA和所有其他蛋白质的表达 毒力决定因素对环境刺激的反应。我们的目标是 以了解这种调节发生的分子机制。至 在我们的遗传分析方面，我们最近构建了B。 包含基因融合的百日咳，这样FHA的表达在 产β-半乳糖苷酶术语和百日咳毒素术语 碱性磷酸酶的产生。事实证明，这些菌株在 VIR基因座突变影响的量化。我们有 确定了几种存在差异的遗传情况 百日咳毒素和FHA的表达，提示不同水平的 这两个毒力决定因素的遗传控制。我们的生物化学 对VIR编码的蛋白质BvgS和BvgA的分析已经进展到 我们已经提纯了BvgA，以及MBP：BvgS融合 蛋白。这使得我们能够开始对假说的体外研究 该蛋白对的蛋白激酶/磷受体活性。我们有 还开始了百日咳杆菌染色体的分析，目标是 构建一张物理地图。这项分析即将完成，并将 这使得我们能够确定B组杆菌毒力决定因素的基因。 百日咳以进化相关的方式联系在一起。

The vir locus of Bordetella pertussis is a central regulatory gene which controls the expression of pertussis toxin, FHA, and all other protein virulence determinants in response to environmental stimuli. Our goal is to understand the molecular mechansims by which this regulation occurs. To aid in our genetic analyses we have recently constructed strains of B. pertussis containing gene fusions such that FHA expression is measured in terms of b-galactosidase production, and pertussis toxin in terms of alkaline phosphatase production. These strains are proving useful in the quantitation of the effects of mutations in the vir locus. We have identified several genetic situations in which there is differential expression of pertussis toxin and FHA, suggesting different levels of genetic control of these two virulence determinants. Our biochemical analysis of the proteins encoded by vir: BvgS and BvgA, have advanced to the point where we have purified BvgA, as well as a MBP:BvgS fusion protein. This has allowed us to begin in vitro studies of the hypothesized protein kinase/phosphoacceptor activities of this protein pair. We have also begun an analysis of the B. pertussis chromosome with the goal of constructing a physical map. This analysis is almost complete and will allow us to determine if the genes for virulence determinants of B. pertussis are linked in an evolutionarily relevant fashion.