Quorum responses & regulated proteolysis in B. subtills

描述（由申请人提供）：某些细菌以密度依赖性方式调节基因表达，这种现象称为“群体感应”。群体反应途径中的关键调节蛋白之一是ComS，其控制参与脂肪酸代谢的基因、已知由交替的σ因子σ-H和推定的转录因子LrpC调节的基因的表达。这项拟议的研究的总体重点是表征由ComS控制的调节途径，重点是群体反应和调节蛋白水解之间可能存在的联系。一个全球性的方法将被用来确定ComS在调节IrpC的表达的作用，通过确定的步骤，其中IrpC的表达受到ComS的影响，表征顺式和反式作用的因素，影响lrpC的表达，并确定LrpC是否负面影响其自身的表达在ComS依赖的方式。一个机械的方法将被用来确定是否稳定的关键调控蛋白控制的ComS，如果是这样，我将描述如何ComS影响这些蛋白质的蛋白水解。了解控制群体反应的调节途径将有助于我们更好地了解细菌如何相互交流。

DESCRIPTION (provided by applicant): Certain bacteria regulate gene expression in a density-dependent manner, a phenomenon referred to as "quorum sensing". One of the key regulatory proteins in the quorum response pathway is ComS, which controls the expression of genes involved in fatty acid metabolism, genes known to be regulated by the alternate sigma factor sigma-H, and the putative transcription factor LrpC. The overall focus of this proposed research is to characterize the regulatory pathways controlled by ComS with an emphasis on possible connections between the quorum response and regulated proteolysis. A global approach will be used to determine the role of ComS in regulating expression of IrpC by identifying the step at which the expression of IrpC is affected by ComS, characterizing cis- and trans-acting factors that affect lrpC expression, and determining whether LrpC negatively affects its own expression in a ComS-dependent manner. A mechanistic approach will be used to determine whether the stability of key regulatory proteins is controlled by ComS and, if so, I will characterize how ComS affects proteolysis of these proteins. Understanding the regulatory pathways governing the quorum response will aid in our better understanding of how bacteria communicate with one another.