Global effects of deletions of the sitABCD, mntH, cbiMNQO and corA genes, encoding transporters for manganese, cobalt and magnesium on protein abundance in Salmonella enterica serovar Typhimurium grown to stationary phase in LB.

<p>The RpoS/σS sigma subunit of RNA polymerase is the master regulator of the general stress response in many Gram-negative bacteria.</p><p>We have shown that in <i>Salmonella enterica </i>serovar Typhimurium, RpoS activates transcription of the <i>sitABCD</i> and <i>mntH&nbsp;</i> genes, involved in iron and manganese transport, and that of <i>corA</i> encoding the main magnesium transporter (Levi-Meyrueis <i>et al</i>. 2014, Metaane <i>et al</i>. 2022, Metaane <i>et al. </i>2023). In addition, RpoS represses expression of the CbiO protein produced from the <i>cbiMNQO</i> operon encoding a high affinity cobalt uptake system (Lago <i>et al.</i> 2017, Metaane <i>et al</i>. 2022, Metaane <i>et al. </i>2023).&nbsp; Moreover, Inductively coupled plasma mass spectrometry analyses have revealed that the Δ<i>rpoS</i> mutation reduces the cellular concentration of manganese and magnesium and increases the concentration of cobalt of stationary phase <i>Salmonella </i>(Metaane <i>et al. </i>2022). These findings suggested that a tight control of uptake and availability of manganese, magnesium and cobalt might be critical for quiescent bacteria. Consistent with this hypothesis, our recent findings unraveled the importance of RpoS and magnesium in the regrowth potential of quiescent <i>Salmonella</i> cells (Metaane <i>et al</i>. 2022).</p><p>Unexpectedly, our recent work revealed that, under magnesium proficient environmental conditions, the absence of the housekeeping Mg2+ transporter CorA is sensed by the cell which induces compensatory mechanisms to minimize the impact of a Δ<i>corA</i> mutation on protein content, magnesium homeostasis, growth, and motility of <i>Salmonella </i>(Metaane <i>et al. </i>2023). In this study, we used a mass spectrometry-based proteomics approach to address the physiological impact of the SitABCD, MntH and CbiMNQO transporters on quiescent&nbsp; <i>Salmonella. </i>A comprehensive quantitative proteomic analysis was performed using wild-type and Δ<i>rpoS </i>strains of <i>Salmonella</i> ATCC14028 carrying deletions of these genes and grown to late stationary phase in nutrient-rich LB medium, <i>i.e</i>. the growth conditions previously used to characterize the RpoS- transcriptome, proteome and ionome (Levi-Meyrueis <i>et al.</i> 2014, Lago <i>et al. </i>2017, Metaane <i>et al. </i>2022). Since CorA can also import cobalt, a Δ<i>corA</i> mutation was included and combined with the Δ<i>cbiMNQO</i> mutation. &nbsp;&nbsp;&nbsp;&nbsp;</p><p><strong>Accession number</strong>.The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier <strong>PXD043760</strong>.</p><p><strong>This work was supported by the French National Research Agency (ANR-19-CE44-0005-01, PERIOMET project).</strong></p><p><strong>References</strong></p><p>Levi-Meyrueis C, Monteil V, Sismeiro O, Dillies MA, Monot M, Jagla B, Coppée J-Y, Dupuy B, Norel F. Expanding the RpoS/sigmaS-network by RNA sequencing and identification of sigmaS-controlled small RNAs in <i>Salmonella</i>. PloS one. 2014;9(5):e96918.</p><p>Lago M, Monteil V, Douche T, Guglielmini J, Criscuolo A, Maufrais C, Matondo M, Norel F. Proteome remodelling by the stress sigma factor RpoS/sigma(S) in <i>Salmonella</i>: identification of small proteins and evidence for post-transcriptional regulation. Scientific reports. 2017;7(1):2127.</p><p>Metaane S, Monteil V, Ayrault S, Bordier L, Levi-Meyreuis C, Norel F. The stress sigma factor sigmaS/RpoS counteracts Fur repression of genes involved in iron and manganese metabolism and modulates the ionome of <i>Salmonella enterica </i>serovar Typhimurium. PLoS one. 2022;17(3):e0265511.</p><p>Metaane S, Monteil V, Douché T, Giai Gianetto Q, Matondo M, Maufrais C, Norel F. Loss of CorA, the primary magnesium transporter of <i>Salmonella, </i>is alleviated by MgtA and PhoP-dependent compensatory mechanisms. PloS one 2023;18(9):e0291736.</p><p>NOREL, &amp; MONTEIL. (2023). Ionome analysis of Salmonella mutants by Inductively coupled plasma mass spectrometry (ICP-MS) (Version v1) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.8085835</p><p>&nbsp;</p><p>&nbsp;</p>