University of Würzburg, Institute of Hygiene and Microbiology, Würzburg, Germany.
Int J Med Microbiol. 2011 Apr;301(4):325-33. doi: 10.1016/j.ijmm.2010.11.007. Epub 2011 Feb 2.
Transcriptional regulators play an important role for the survival of Neisseria meningitidis within its human host. We have recently shown that FarR acts as transcriptional repressor of the adhesin nadA in N. meningitidis. Here, we examined the FarR regulon by microarray analyses, qRT-PCR, and electrophoretic mobility shift assays, revealing that FarR is a highly specific repressor of nadA. We demonstrate by reporter gene fusion assays that alterations of the FarR binding site within the nadA promoter are sufficient to induce transcription of nadA. Furthermore, farR expression is growth phase-dependent. The highest transcription rate was observed in the late-exponential growth phase of meningococci. Upon contact with active components of the complement system in normal human serum, expression of farR is slightly downregulated. Concluding, we present FarR as an exquisitely specialized, growth phase-dependent, possibly complement-responsive transcriptional regulator in N. meningitidis.
转录调节因子在脑膜炎奈瑟菌在其人体宿主中的生存中起着重要作用。我们最近表明，FarR 作为脑膜炎奈瑟菌黏附素 nadA 的转录抑制剂。在这里，我们通过微阵列分析、qRT-PCR 和电泳迁移率变动分析检查了 FarR 调控子，结果表明 FarR 是 nadA 的高度特异性抑制剂。我们通过报告基因融合分析证明，nadA 启动子中 FarR 结合位点的改变足以诱导 nadA 的转录。此外，farR 的表达与生长阶段有关。在脑膜炎球菌的晚指数生长阶段观察到最高的转录速率。与正常人血清中补体系统的活性成分接触后，farR 的表达略有下调。总之，我们将 FarR 呈现为一种高度专业化、生长阶段依赖性、可能对补体有反应的转录调节剂。
