Quorum responses & regulated proteolysis in B. subtills

描述（由申请人提供）：某些细菌以密度依赖的方式调节基因表达，这种现象被称为“群体感应”。群体反应途径的关键调节蛋白之一是ComS，它控制脂肪酸代谢相关基因的表达，已知由备用sigma因子sigma- h和推定的转录因子LrpC调节的基因。本研究的总体重点是表征ComS控制的调控途径，重点是群体反应和受调节的蛋白质水解之间的可能联系。通过确定ComS影响IrpC表达的步骤，表征影响lrpC表达的顺式和反式因子，以及确定lrpC是否以ComS依赖的方式对其自身表达产生负面影响，将采用一种全球方法来确定ComS在调节IrpC表达中的作用。将使用一种机制方法来确定关键调节蛋白的稳定性是否由ComS控制，如果是，我将描述ComS如何影响这些蛋白的蛋白水解。了解控制群体反应的调节途径将有助于我们更好地理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.