B.SUBTILIS PHO REGULON SIGNAL TRANSDUCTION NETWORK

双成分信号是信号的主要形式 在原核生物中的转导，在真核生物中有独特的例子。年底 对数生长的“过渡状态”芽孢杆菌细胞接受多个 来自环境的信号同时报告条件， 如温度、细胞密度、营养可用性和氧张力。这些 处理信号以确定最合适的基因表达， 代谢反应来维持生存。B的表征。枯草芽孢杆菌 信号转导网络已经让假设，“处理的 多个信号是由涉及多个 两个组成部分的系统，其功能是建立依赖关系或层次结构 系统之间。调节子之间的这种重叠提供了一种机制， 整合和信号输入所经历的有机体在任何一个时间。" 该提案侧重于B。枯草杆菌Pho调节子信号 转导网络，以了解多个双组分系统如何相互作用 参与信号传导网络。PI计划：1） 确定调节子的重叠是否发生在转录水平， phoPR操纵子编码初级Pho双组分调节子， 蛋白质控制四种phoPR启动子中的每一种的表达; 2） 确定两个双组分调节器ResD和PhoP如何相互作用， 每一个都是必需的，但不足以转录操纵子编码 监管对之一，ResD和ResE; 3）确定其他监管机构 建议协助催化领域的phoR，使该领域足够 以控制Pho调节子的磷酸盐缺乏诱导; 4）确定 如果反应调节器之间域相互作用的差异解释了 靶DNA-应答调节剂相互作用或蛋白质寡聚 关于磷酸化。

Two-component signaling is the principal form of signal transduction in prokaryotes with distinctive examples in eukaryotes. At the end of logarithmic growth, the "transition state" Bacillus cell receives multiple signals from the environment that are simultaneously reporting conditions such as temperature, cell density, nutrition availability and oxygen tension. These signals are processed to determine the most appropriate gene expression and metabolic response for survival. The characterization of the B. subtilis Pho signal transduction network has let to the hypothesis that "The processing of the multiple signals is accomplished by regulatory networks involving multiple two-component systems that function to establish dependencies or hierarchies between systems. This overlap between regulons provides a mechanism for signal integration and signal input experienced by the organism at any one time." The proposal focuses on the B. subtilis Pho regulon signal transduction network to understand how multiple two-component systems interact to participate in a signal transduction network. The PI is planning to: 1) determine if overlap of regulons occurs at the level of transcription of the phoPR operon encoding the primary Pho two-component regulators by asking what proteins control the expression of each of the four phoPR promoters; 2) determine how two two-component regulators, ResD and PhoP, interact, such that each is essential but not sufficient for transcription of an operon encoding one of the regulatory pairs, ResD and ResE; 3) identify additional regulators proposed to assist the catalytic domain of PhoR, making that domain sufficient to control the phosphate deficiency induction of the Pho regulon; 4) determine if differences in domain interaction among response regulators explains differences in target DNA-response regulator interactions or protein oligomeric state with respect to phosphorylation.