Comprehensive determination of transcription factor location in Francisella

描述（由申请方提供）：土拉热弗朗西斯菌是土拉菌病的病原体，是目前已知的最具传染性的细菌病原体之一，由于其可用作生物武器，因此是NIAID A类优先病原体。与许多其他细胞内病原体不同，弗朗西斯菌编码相对较少的转录调节因子。虽然这些转录调节因子中的一些已知在细胞内存活所需的毒力基因的控制中发挥关键作用，但对于其中的大多数，尚不知道它们是否在毒力基因表达的控制中发挥作用。在这里，我们建议使用染色质免疫沉淀（ChIP）加上完全平铺的高密度DNA微阵列（ChIP芯片），以确定每个预测的转录调节因子在弗朗西斯的调控目标（即基因组位置）。以这种方式，我们将能够（i）理解已知在发病机制中起重要作用的某些调节因子如何实现对它们调节的基因的控制，（ii）全面确定弗朗西斯氏菌属中转录调节因子的哪个子集参与控制已知毒力基因的表达，和（iii）揭示弗朗西斯菌属中控制毒力基因表达的调控网络之间的任何假定联系如何允许细胞内生长所需的基因的协调表达。通过确定弗朗西斯菌中每个转录因子的基因组位置，我们将能够在转录水平上定义细胞中运行的所有毒力调控网络，从而确定可能的治疗干预点。 公共卫生相关性：F.土拉热病是土拉菌病的病原体，是一种潜在的生物武器，也是NIAID A类优先病原体。拟议的实验有望揭示一种重要的细胞内病原体如何调节引起疾病所需的基因表达。我们的工作对兔热症治疗方法的发展具有重要意义。

DESCRIPTION (provided by applicant): Francisella tularensis, the aetiological agent of tularemia, is one of the most infectious bacterial pathogens currently known and a NIAID category A priority pathogen because of its potential for use as a biological weapon. Unlike many other intracellular pathogenes Francisella encodes relatively few transcription regulators. Although some of these transcription regulators are known to play critical roles in the control of virulence genes required for intracellular survival, for the majority of them it is not known whether they play a role in the control of virulence gene expression. Here we propose to use chromatin immunoprecipitation (ChIP) coupled with fully tiled high density DNA microarrays (ChIP-on-chip) to identify the regulatory targets (i.e. genomic locations) for every predicted transcription regulator in Francisella. In this manner we will be able to (i) understand how certain regulators that are known to play an important role in pathogenesis achieve control over the genes they regulate, (ii) comprehensively determine which subset of the transcription regulators in Francisella are involved in controlling the expression of known virulence genes, and (iii) reveal how any putative connections between the regulatory networks governing virulence gene expression in Francisella allow for the coordinate expression of genes required for intracellular growth. By determining the genomic locations of every transcription factor in Francisella we will be able to define all of the virulence regulatory networks operating in the cell at the level of transcription, and thus identify possible points of therapeutic intervention. PUBLIC HEALTH RELEVANCE: F. tularensis, the causative agent of tularemia, is a potential bioweapon and a NIAID category A priority pathogen. The proposed experiments are expected to reveal how an important intracellular pathogen regulates the expression of genes that are required to cause disease. Our work has implications for the development of therapeutics for the treatment of tularemia.