GLOBAL REGULATION OF VIRULENCE FACTOR IN BORDETELLA PERTUSSIS

百日咳博德特氏菌vir基因座是一个中心调控基因， 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。 到 在我们的遗传分析中，我们最近构建了B的菌株。 百日咳疫苗中的FHA表达， 就β-半乳糖苷酶的产生而言， 碱性磷酸酶产生。 这些菌株被证明是有用的 vir基因座中突变的影响的定量。 我们有 发现了几种遗传情况， 百日咳毒素和FHA的表达，表明不同水平的 这两个毒力决定因素的遗传控制。 我们的生化 对vir编码的蛋白质的分析：BvgS和BvgA，已经进展到 我们已经纯化了BvgA，以及MBP：BvgS融合体， 蛋白 这使我们能够开始体外研究的假设， 蛋白激酶/磷酸受体活性。 我们有 也开始分析B。百日咳染色体的目的是 构建物理地图。 这一分析几乎完成，并将 使我们能够确定B. 百日咳是以进化相关的方式联系在一起的。

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.