Department of Molecular Microbiology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland.
Int J Mol Sci. 2023 Jul 6;24(13):11157. doi: 10.3390/ijms241311157.
Iron is both essential for and potentially toxic to bacteria, so the precise maintenance of iron homeostasis is necessary for their survival. Our previous study indicated that in the human enteropathogen , the regulator OmpR directly controls the transcription of the , and genes, encoding the ferric uptake repressor and two transporters of ferric siderophores, respectively. This study was undertaken to determine the significance of the RNA chaperone Hfq and the small RNAs OmrA and RyhB1 in the post-transcriptional control of the expression of these OmpR targets. We show that Hfq silences , and expression post-transcriptionally and negatively affects the production of FLAG-tagged Fur, FecA and FepA proteins. In addition, we found that the gene is under the negative control of the sRNA RyhB1, while and are negatively regulated by the sRNA OmrA. Finally, our data revealed that the role of OmrA results from a complex interplay of transcriptional and post-transcriptional effects in the feedback circuit between the regulator OmpR and the sRNA OmrA. Thus, the expression of , and is subject to complex transcriptional and post-transcriptional regulation in order to maintain iron homeostasis in .
铁既是细菌生存所必需的，又可能对其有毒，因此精确维持铁稳态对其生存是必要的。我们之前的研究表明，在人类肠道病原体 中，调节因子 OmpR 直接控制编码亚铁摄取阻遏物和两种亚铁载体转运蛋白的 、 和 基因的转录。本研究旨在确定 RNA 伴侣 Hfq 和小 RNA OmrA 和 RyhB1 在这些 OmpR 靶基因的转录后调控中的意义。我们表明 Hfq 沉默 、 和 的转录后表达，并负调控 FLAG 标记的 Fur、FecA 和 FepA 蛋白的产生。此外，我们发现 基因受到小 RNA RyhB1 的负调控，而 和 则受小 RNA OmrA 的负调控。最后，我们的数据显示，OmrA 的作用是由于调节因子 OmpR 和小 RNA OmrA 之间反馈回路中的转录和转录后效应的复杂相互作用所致。因此，为了维持 在铁稳态中， 的表达受到复杂的转录和转录后调控。
