CONTROL OF SIGMA BETA ACTIVITY IN B SUBTILIS

AlphaBeta是枯草芽孢杆菌的二级α因子。 阿尔法贝塔- 含有RNA聚合酶识别几个基因的启动子， 在指数生长结束时和“热休克”期间表达。 alphaB的活性受到一种不寻常的负性级联反应的调节， 调节剂，其包括抗σ蛋白（RsbW），所述抗σ蛋白结合至 alphaB并阻断其与RNA聚合酶结合的能力。 的 调节子由三个基因（rsbV、rsbW和rsbX）编码， 与alphaB结构基因共转录。 我们建议确定 这些监管机构之间的职能关系及其 目标、对其实施控制的机制以及 他们回应的信号。 α B及其受体的免疫探针 监管机构已经制定，并将用于监测他们的 丰度、潜在状态变化和关联。 调节 α B依赖性转录将在体外重建并使用 直接测试监管者和目标之间的互动。 rsbV、W、X系统将以各种组合进行重构， 通过将一种或多种依赖性转录和 其他监管机构的状态。 使用不适当的激活 α依赖性报告基因作为筛选标准，基因突变 其产物影响rsbV，W，X系统的活性， 分离和分析，以确定信号的性质， RsbV、W和X响应。 最后，转座子产生的 报告基因融合将用于鉴定和表征 由alphaB系统控制的额外操纵子。 控制 辅助α因子活性对正常细胞是关键的 增长 不适当的激活alphaB会导致一个立即和 其调节子的致死诱导。 特别有趣的是， alphaB的控制是通过抗σ因子进行调节。 抗α 因子代表了原核生物中调节分子的“新类别”。 它们的作用模式、调节和它们所响应的信号 是未知的。 解开他们的财产不仅会提供新的 全球基因控制的见解，但也可能定义不可预见的目标 用于抗菌剂。

AlphaBeta is a secondary alpha factor of Bacillus subtilis. Alpha Beta- containing RNA polymerase recognizes the promoters of several genes that are expressed at the end of exponential growth and during "Heat Shock". The activity of alphaB is modulated by an unusual cascade of negative regulators which includes an anti-sigma protein (RsbW) that binds to alphaB and blocks its ability to associate with RNA polymerase. The regulators are encoded by three genes (rsbV, rsbW and rsbX) that are cotranscribed with the alphaB structural gene. We propose to determine the functional relationships between these regulators and their target(s), the mechanism by which the effect their control and the signals to which they respond. Immunological probes for alphaB and its regulators have been developed and will be used to monitor their abundance, potential change of state, and associations. Regulated alphaB-dependent transcription will be reconstituted in vitro and used to directly test the interactions among the regulators and their targets. The rsbV, W, X system will be reconstituted in various combinations and ratios in vivo by placing one or more of the dependent transcription and the state of the other regulators. Using inappropriate activation of a alpha-dependent reporter gene as a screening criteria, mutations in genes whose products influence the activity of the rsbV, W, X system will be isolated and analyzed to determined the nature of the signals to which RsbV, W, and X respond. Finally a transposon-generated collection of reporter gene fusions will be used to identify and characterize additional operons that are controlled by the alphaB system. Control of the activity of ancillary alpha factors is critical to normal cell growth. Inappropriate activation of alphaB leads to an immediate and lethal induction of its regulon. A particularly intriguing aspects of alphaB control is its regulation by anti sigma factor. Anti-alpha factors represent a "new class" of regulatory molecules in prokaryotes. Their mode of action, regulation and the signals to which they respond are unknown. Unraveling their properties will not only provide new insights for global gene control but may also define unforeseen targets for antimicrobial agents.