The role of cyclic-di-AMP in the regulation of Chlamydia cellular functions

描述（申请人提供）：沙眼衣原体是致盲性沙眼和许多性传播疾病的病原体，存在两种发育形式：感染性初级体（EB）和复制网状体（RB）。EB和RB形式之间的过渡是这种专性细菌病原体生命周期的重要步骤。然而，对这些发育变化背后的环境线索和分子机制知之甚少。我们最近确定沙眼衣原体EBs积累环二腺苷单磷酸腺苷（c-二磷酸腺苷），这是一种新发现的核酸代谢物，有助于革兰氏阳性细菌的细胞壁稳态。在革兰氏阴性菌中，结构相关的环二核苷酸c-di-GMP是对生物膜形成和微生物毒力重要的酶、基因表达和核糖开关的变构调节剂。我们假设c-di-AMP调节蛋白质和/或RNA功能，促进RB向EB的转化，并可能促进毒力。在这个探索性研究项目中，我们概述了一些实验，以确定调节衣原体二腺苷酸环化酶的蛋白质，以及可能是c-二磷酸腺苷酸介导调节靶点的蛋白质和RNA。我们将采用我们实验室开发的新的生化和遗传学方法来评估c-di-AMP及其鉴定的靶点在衣原体发育和发病机制中的作用。

DESCRIPTION (provided by applicant): Chlamydia trachomatis, the causative agent of blinding trachoma and many sexually transmitted diseases, exists in two developmental forms: an infectious elementary body (EB) and a replicative reticulate body (RB). The transition between EB and RB forms is an essential step in the life cycle of this obligate bacterial pathogen. However, remarkably little is known about the environmental cues and molecular mechanism underlying these developmental changes. We recently determined that C. trachomatis EBs accumulate cyclic di-adenosyl monophosphate (c-di-AMP), a newly identified nucleic acid metabolite that contributes to cell wall homeostasis in gram-positive bacteria. In gram-negative bacteria, the structurally related cyclic dinucleotide c-di-GMP is an allosteric regulator of enzymes, gene expression and riboswitches important for biofilm formation and microbial virulence. We hypothesize that c-di-AMP regulates protein and/or RNA functions to promote the RB to EB transition and possibly virulence. In this exploratory research program, we outline experiments to identify proteins that regulate the Chlamydia diadenylate cyclase, and protein(s) and RNA(s) that may be targets of c-di-AMP-mediated regulation. We will employ new biochemical and genetic methods developed in our laboratory to assess the role of c-di-AMP and its identified target(s) in chlamydial development and pathogenesis.