Northwestern University Feinberg School of Medicine, Department of Microbiology-Immunology, Chicago, Illinois, USA.
J Bacteriol. 2014 May;196(9):1659-70. doi: 10.1128/JB.01456-13. Epub 2014 Feb 14.
Small noncoding RNA (sRNA) molecules are integral components of the regulatory machinery for many bacterial species and are known to posttranscriptionally regulate metabolic and stress-response pathways, quorum sensing, virulence factors, and more. The Yop-Ysc type III secretion system (T3SS) is a critical virulence component for the pathogenic Yersinia species, and the regulation of this system is tightly controlled at each step from transcription to translocation of effectors into host cells. The contribution of sRNAs to the regulation of the T3SS in Yersinia has been largely unstudied, however. Previously, our lab identified a role for the sRNA chaperone protein Hfq in the regulation of components of the T3SS in the gastrointestinal pathogen Yersinia pseudotuberculosis. Here we present data demonstrating a similar requirement for Hfq in the closely related species Yersinia pestis. Through deep sequencing analysis of the Y. pestis sRNA-ome, we found 63 previously unidentified putative sRNAs in this species. We identified a Yersinia-specific sRNA, Ysr141, carried by the T3SS plasmid pCD1 that is required for the production of multiple T3SS proteins. In addition, we show that Ysr141 targets an untranslated region upstream of yopJ to posttranscriptionally activate the synthesis of the YopJ protein. Furthermore, Ysr141 may be an unstable and/or processed sRNA, which could contribute to its function in the regulation of the T3SS. The discovery of an sRNA that influences the synthesis of the T3SS adds an additional layer of regulation to this tightly controlled virulence determinant of Y. pestis.
小非编码 RNA (sRNA) 分子是许多细菌物种调控机制的组成部分，已知它们可以对代谢和应激反应途径、群体感应、毒力因子等进行转录后调控。Yop-Ysc 型 III 型分泌系统 (T3SS) 是致病性耶尔森氏菌的关键毒力成分，该系统的调节从转录到效应子易位到宿主细胞都受到严格控制。然而，sRNA 对耶尔森氏菌 T3SS 的调节作用在很大程度上尚未得到研究。此前，我们实验室发现 sRNA 伴侣蛋白 Hfq 在胃肠道病原体假结核耶尔森氏菌 T3SS 组件的调节中起作用。在这里，我们提出的数据表明 Hfq 在密切相关的物种鼠疫耶尔森氏菌中也有类似的要求。通过对鼠疫耶尔森氏菌 sRNA 组的深度测序分析，我们在该物种中发现了 63 个以前未识别的假定 sRNA。我们鉴定了一种 Yersinia 特异性 sRNA，Ysr141，由 T3SS 质粒 pCD1 携带，是多种 T3SS 蛋白产生所必需的。此外，我们表明 Ysr141 靶向 yopJ 上游的非翻译区，以转录后激活 YopJ 蛋白的合成。此外，Ysr141 可能是一种不稳定和/或加工的 sRNA，这可能有助于其在 T3SS 调节中的功能。发现一种影响 T3SS 合成的 sRNA 为鼠疫耶尔森氏菌这种严格控制的毒力决定因素增加了一个额外的调节层。
