Howery Kristen E, Clemmer Katy M, Rather Philip N
Department of Microbiology and Immunology, Emory University, 3001 Rollins Research Center, Atlanta, GA, USA.
Research Service, Atlanta VA Medical Center, Decatur, GA, USA.
Curr Genet. 2016 Nov;62(4):775-789. doi: 10.1007/s00294-016-0579-1. Epub 2016 Mar 2.
The overall role of the Rcs phosphorelay in Proteus mirabilis is largely unknown. Previous work had demonstrated that the Rcs phosphorelay represses the flhDC operon and activates the minCDE cell division inhibition system. To identify additional cellular functions regulated by the Rcs phosphorelay, an analysis of RNA-seq data was undertaken. In this report, the results of the RNA-sequencing are discussed with an emphasis on the predicted roles of the Rcs phosphorelay in swarmer cell differentiation, motility, biofilm formation, and virulence. RcsB is shown to activate genes important for differentiation and fimbriae formation, while repressing the expression of genes important for motility and virulence. Additionally, to follow up on the RNA-Seq data, we demonstrate that an rcsB mutant is deficient in its ability to form biofilm and exhibits enhanced virulence in a Galleria mellonella waxworm model. Overall, these results indicate the Rcs regulon in P. mirabilis extends beyond flagellar genes to include those involved in biofilm formation and virulence. Furthermore, the information presented in this study may provide clues to additional roles of the Rcs phosphorelay in other members of the Enterobacteriaceae.
Rcs磷信号转导系统在奇异变形杆菌中的整体作用很大程度上尚不清楚。先前的研究表明，Rcs磷信号转导系统可抑制flhDC操纵子并激活minCDE细胞分裂抑制系统。为了确定受Rcs磷信号转导系统调控的其他细胞功能，我们对RNA测序数据进行了分析。在本报告中，我们将讨论RNA测序的结果，重点关注Rcs磷信号转导系统在游动细胞分化、运动性、生物膜形成和毒力方面的预测作用。结果表明，RcsB可激活对分化和菌毛形成重要的基因，同时抑制对运动性和毒力重要的基因的表达。此外，为了跟进RNA测序数据，我们证明rcsB突变体形成生物膜的能力存在缺陷，并且在大蜡螟模型中表现出增强的毒力。总体而言，这些结果表明奇异变形杆菌中的Rcs调控子不仅包括鞭毛基因，还包括参与生物膜形成和毒力的基因。此外，本研究提供的信息可能为Rcs磷信号转导系统在肠杆菌科其他成员中的其他作用提供线索。
