Towards new elements involved in magnesium and cobalt trafficking in Salmonella serovar Typhimurium
Creators: name: NOREL, Françoise
name: MONTEIL Véronique
name: METAANE Selma
Publisher: name: Zenodo
Year: 2023
Subjects: Salmonella
CorA
corB
CorC
CorD
toxicity
magnesium
cobalt

description: Our recent publication has shed light on the importance of magnesium in the ability of quiescent Salmonella cells to resume growth (Metaane et al. 2022).

Salmonella imports magnesium via three known transporters, the widely conserved CorA transporter and the MgtA and MgtB P-type ATPases. CorA is expressed under various growth conditions whereas the other two magnesium transporters, MgtA and MgtB, are expressed under conditions of magnesium starvation under the positive control of the PhoP-PhoQ regulatory system (Groisman et al. 2021). CorA can perform magnesium influx and efflux and it is also able to import cobalt and nickel when these elements are present in high concentrations in the growth medium. Thus a corA mutant is more resistant to cobalt (cor stands for "cobalt resistant") and nickel than the wild-type strain. Our recent finding that corA is activated by the stress sigma factor sigmaS/RpoS in stationary phase Salmonella (Metaane et al. 2022, 2023) prompted us to assess the physiological impact of a ΔcorA mutation on quiescent Salmonella cells by analytical and global analyses (Metaane et al. 2023).

CorA proteins are a unique class of transporters and are widespread in the Bacteria and Archaea, with functional homologs in eukaryotes. Many questions about CorA and its full role in Salmonella physiology remain unanswered. During the study of magnesium and cobalt transport by CorA in Salmonella, three loci named corB, corC and corD, involved in resistance to cobalt and magnesium efflux have been discovered by Gibson et al. (1991). It was proposed that CorB, CorC and CorD contribute to the efflux of divalent cations by CorA, either by coupling the transport of cations by CorA to an energy source, or as a cation sensor for the CorA protein.  The corB, corC and corD genes have not been further characterized in Salmonella and their function remains unclear to date. We have identified the corB, corC and corD genes as corresponding to the yfjD, ybeX and possibly apaG genes, respectively, in Salmonella serovar Typhimurium strain ATCC14028. We have constructed deletions in these genes in order to study their physiological impact in Salmonella. In the present study, we report the construction of mutants and their resistance phenotype towards cobalt, nickel and magnesium toxicity. 

In other studies:



The bacterial two hybrid system (BACTH) was used to find out potential physical interactions between CorA, CorB(YfjD), CorC(YbeX) and ApaG. NOREL, F., METAANE Selma, & MONTEIL Véronique. (2023). Detection of physical interactions between the magnesium transporter CorA and other Cor proteins using the bacterial two hybrid system (BACTH). Zenodo. https://doi.org/10.5281/zenodo.7994619

The role of CorC was further characterized by analytical studies and global proteomics. NOREL, F., KUMAR, S., BOLARD, A., MONTEIL, V., & METAANE, S. (2023). Characterization of molecular determinants involved in magnesium homeostasis of Salmonella: Understanding the role of CorC protein. Zenodo. https://doi.org/10.5281/zenodo.10301612.The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD043903.


See also:

Phegnon, L., Uttenweiler-Joseph, S., & Létisse, F. (2024). EXTRAMETABOLOME ANALYSIS OF SALMONELLA corC MUTANTS BY NMR [Data set]. Zenodo. https://doi.org/10.5281/zenodo.10908203

This work was supported by the French National Research Agency (ANR-19-CE44-0005-01, PERIOMET project).



Gibson MM, Bagga DA, Miller CG, Maguire ME. Magnesium transport in Salmonella typhimurium: the influence of new mutations conferring Co2+ resistance on the CorA Mg2+ transport system. Molecular microbiology. 1991;5(11):2753-62.

Groisman EA, Duprey A, Choi J. How the PhoP/PhoQ System Controls Virulence and Mg(2+) Homeostasis: Lessons in Signal Transduction, Pathogenesis, Physiology, and Evolution. Microbiology and molecular biology reviews: MMBR. 2021; 85(3):e0017620.

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 Salmonella enterica serovar Typhimurium. PloS one. 2022;17(3):e0265511.

Metaane S, Monteil V, Douché T, Giai Gianetto Q, Matondo M, Maufrais C, Norel F. Loss of CorA, the primary magnesium transporter of Salmonella, is alleviated by MgtA and PhoP-dependent compensatory mechanisms. PloS one. 2023;18(9):e0291736.