Complex Traits Group, Department of Microbiology, McGill University Montreal, QC, Canada.
Front Microbiol. 2011 May 6;2:98. doi: 10.3389/fmicb.2011.00098. eCollection 2011.
Legionella pneumophila is a gram-negative bacterial species that is ubiquitous in almost any aqueous environment. It is the agent of Legionnaires' disease, an acute and often under-reported form of pneumonia. In mammals, L. pneumophila replicates inside macrophages within a modified vacuole. Many protein regulators have been identified that control virulence-related properties, including RpoS, LetA/LetS, and PmrA/PmrB. In the past few years, the importance of regulation of virulence factors by small regulatory RNA (sRNAs) has been increasingly appreciated. This is also the case in L. pneumophila where three sRNAs (RsmY, RsmZ, and 6S RNA) were recently shown to be important determinants of virulence regulation and 79 actively transcribed sRNAs were identified. In this review we describe current knowledge about sRNAs and their regulatory properties and how this relates to the known regulatory systems of L. pneumophila. We also provide a model for sRNA-mediated control of gene expression that serves as a framework for understanding the regulation of virulence-related properties of L. pneumophila.
嗜肺军团菌是一种革兰氏阴性细菌，几乎存在于任何水相环境中。它是军团病的病原体，一种急性且常常被低估的肺炎形式。在哺乳动物中，嗜肺军团菌在经过修饰的空泡内的巨噬细胞内复制。已经鉴定出许多控制毒力相关特性的蛋白质调节剂，包括 RpoS、LetA/LetS 和 PmrA/PmrB。在过去的几年中，越来越多的人认识到小调控 RNA（sRNA）对毒力因子的调控的重要性。嗜肺军团菌也是如此，最近有研究表明三种 sRNA（RsmY、RsmZ 和 6S RNA）是毒力调节的重要决定因素，并且鉴定出了 79 个活跃转录的 sRNA。在这篇综述中，我们描述了关于 sRNA 及其调控特性的最新知识，以及这与嗜肺军团菌已知的调控系统有何关联。我们还提供了一个 sRNA 介导的基因表达调控模型，作为理解嗜肺军团菌与毒力相关特性的调控的框架。
