GrgA: Key Regulator of Chlamydial Physiology and potential Antichlamydial Target

 描述（由申请人提供）：这项新的R21资助的目标是确定a）一种命名为GrgA的新型衣原体特异性转录因子如何通过调节基因表达来控制衣原体生长，以及B）GrgA是否是已被公认为新型抗衣原体药物的亚苄基酰肼的靶点。衣原体是一种专性细胞内细菌，具有独特的发育周期。它是最常见的性传播细菌病原体。性传播衣原体感染常导致不孕、流产， 宫外孕和盆腔炎。转录不仅控制衣原体的生长和致病性，而且代表衣原体感染的有效治疗靶点。我们发现了一种非常新颖的转录因子，我们称之为GrgA。GrgA仅由衣原体编码，通过与转录因子的非保守区相互作用，在体外激活启动子的转录，所述启动子需要命名为转录因子66的初级或管家转录因子（RNAP聚合酶的亚基）。进一步的证据支持这一假设，即GrgA在衣原体生长的调节中起着关键作用，并且是具有治疗和预防潜力的抗衣原体药物的潜在靶点。我们提出了两个具体目标来检验这一假设。在目标1中，我们将确定GrgA的调节子，并确定GrgA活性的改变如何影响转录组表达，以及衣原体的生长和发育特性。在目标2中，我们将确定GrgA在苯亚甲基酰肼抑制衣原体生长中的作用，苯亚甲基酰肼是一组新的抗衣原体药物，对宿主细胞和有益的乳酸杆菌具有不可检测的毒性，这些乳酸杆菌在健康育龄妇女的阴道微生物组中占主导地位。我们预计这项研究的三个重要成果：a）这项研究将产生对衣原体转录调控的见解; B）我们可以确认GrgA是苄叉酰肼的靶点; c）随着药物靶向机制的阐明，苄叉酰肼可以证明作为研究衣原体生物学的化学探针有价值。

 DESCRIPTION (provided by applicant): The goals of this new R21 grant are to determine a) how a novel Chlamydia-specific transcription factor designated GrgA controls chlamydial growth by regulating gene expression, and b) whether GrgA is a target for benzylidene acylhydrazides, which have been recognized as novel antichlamydials. Chlamydia is an obligate intracellular bacterium with a unique developmental cycle. It is the most common sexually transmitted bacterial pathogen. Sexually transmitted chlamydial infection often leads to infertility, abortion, ectopic pregnancy and pelvic inflammatory disease. Transcription not only controls chlamydial growth and pathogenicity, but also represents an effective therapeutic target for chlamydial infections. We have identified a highly novel transcription factor that we call GrgA. Encoded by chlamydiae only, GrgA activates transcription in vitro from promoters that require the primary or housekeeping  factor (a subunit of the RNAP polymerase) designated 66 by interacting with the non-conserved region of the  factor. Further evidence support the hypothesis that GrgA plays a critical role in the regulation of chlamydial growth, and is potentially a target for antichlamydials with therapeutic and prophylactic potentials. We propose two Specific Aims to test this hypothesis. In Aim 1, we will identify the regulon of GrgA, and determine how alterations in the GrgA activity affect the transcriptome expression, and growth and developmental properties in Chlamydia. In Aim 2, we will determine the role of GrgA in chlamydial growth inhibition by benzylidene acylhydrazides, a new group of antichlamydials with undetectable toxicity to host cells and beneficial lactobacilli that dominate the vaginal microbiome of healthy, reproductive-age women. We anticipate three significant outcomes from this study: a) this research will yield insights into transcription regulation in chlamydia; b) we may confirm that GrgA is a target of benzylidene acylhydrazides; and c) with an elucidation of the drug targeting mechanism, benzylidene acylhydrazides could prove valuable as chemical probes for studying chlamydial biology.