Open AccessSynthesis of the NarP response regulator of nitrate respiration in Escherichia coli is regulated at multiple levels by Hfq and small RNAs
Author(s) -
Anaïs Brosse,
Pierre Boudry,
Anne Walburger,
Axel Magalon,
Maude Guillier
Publication year - 2022
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/gkac504
Subject(s) - biology , psychological repression , response regulator , transfer rna , small rna , transcription (linguistics) , eukaryotic translation , regulation of gene expression , oxygen tension , transcriptional regulation , rna , anaerobic respiration , gene expression , genetics , escherichia coli , translation (biology) , microbiology and biotechnology , gene , messenger rna , mutant , bacteria , oxygen , linguistics , philosophy , chemistry , organic chemistry
Two-component systems (TCS) and small RNAs (sRNA) are widespread regulators that participate in the response and the adaptation of bacteria to their environments. TCSs and sRNAs mostly act at the transcriptional and post-transcriptional levels, respectively, and can be found integrated in regulatory circuits, where TCSs control sRNAs transcription and/or sRNAs post-transcriptionally regulate TCSs synthesis. In response to nitrate and nitrite, the paralogous NarQ-NarP and NarX-NarL TCSs regulate the expression of genes involved in anaerobic respiration of these alternative electron acceptors to oxygen. In addition to the previously reported repression of NarP synthesis by the SdsN137 sRNA, we show here that RprA, another Hfq-dependent sRNA, also negatively controls narP. Interestingly, the repression of narP by RprA actually relies on two independent mechanisms of control. The first is via the direct pairing of the central region of RprA to the narP translation initiation region and presumably occurs at the translation initiation level. In contrast, the second requires only the very 5' end of the narP mRNA, which is targeted, most likely indirectly, by the full-length or the shorter, processed, form of RprA. In addition, our results raise the possibility of a direct role of Hfq in narP control, further illustrating the diversity of post-transcriptional regulation mechanisms in the synthesis of TCSs.