Analysis of the DksA regulon in the Lyme disease spirochete

摘要 严格反应是细菌用来适应营养缺乏和许多 其他压力。在莱姆病的病原体伯氏疏螺旋体(BB)中，严格的反应是介导的 由丙稀酮核苷酸(P)ppGpp和RNA聚合酶结合蛋白DksA共同作用。最近，我们发现 Dks A在调节BB的毒力方面起着重要作用。首先，dks A在受感染的动物中高度表达 并且是BB感染哺乳动物宿主所必需的。其次，Dks A对BB的最佳增长至关重要。第三, BB需要Dks A来应对代谢应激。最后，除了起到严格应对的作用 作为调节因子，DksA促进有助于BB在宿主中生存的基因的转录和/或翻译。 这些数据结合在一起，提出了我们的假设，即DksA是控制BB毒力基因的主调控因子 表情。这一假设将在两个具体目标中得到解决。在本提案的目标1中，我们将确定 Dks A对Bb在硬蜱体内的存活和持久性的贡献。在目标2中，我们将识别受 在不同的体外和体内条件下，Dks A。这些联合研究将(I)确定整个Dks A调节子； 以及(Ii)提供对Dks A和调节子在体内的重要性的变革性理解。由此产生的 这些发现可能会导致开发新的策略来预防和/或治疗莱姆病。

ABSTRACT Stringent response is a physiological mechanism utilized by bacteria to adapt to nutrient deprivation and many other stresses. In Borrelia burgdorferi (Bb), the etiological agent of Lyme disease, stringent response is mediated by both the alarmone nucleotides (p)ppGpp and the RNA polymerase-binding protein DksA. Recently, we found that DksA plays an essential role in regulating Bb's virulence. First, dksA is highly expressed in infected animals and is required by Bb to infect the mammalian hosts. Second, DksA is critical for Bb's optimal growth. Third, DksA is required by Bb to cope with metabolic stress. Finally, in addition to function as a stringent response regulator, DksA promotes the transcription and/or translation of genes contributing to Bb's survival in the host. These combined data give rise to our hypothesis that DksA is a master regulator governing Bb's virulence gene expression. This hypothesis will be addressed in two Specific Aims. In Aim 1 of this proposal, we will determine the contribution of DksA to Bb's survival and persistence in ticks. In Aim 2, we will identify genes regulated by DksA under various in vitro and in vivo conditions. These combined studies will (i) define the entire DksA regulon; and (ii) provide a transformative understanding of the in vivo importance of DksA and the regulon. Resultant findings could lead to the development of new strategies to prevent and/or treat Lyme disease.