| Autor: |
Vézina Bédard, A.-S., Michaud, A., Quenette, F., Singh, N., de Lemos Martins, F., Wade, J.T., Guillier, M., Lafontaine, D.A. |
| Zdroj: |
RNA Biology; December 2024, Vol. 21 Issue: 1 p1171-1183, 13p |
| Abstrakt: |
ABSTRACTIn Escherichia coli, transport of magnesium ions across the cellular membrane relies on MgtA and CorA transporters. While the expression of mgtAis controlled by the two-component system PhoQ/PhoP and 5’ upstream region elements, corAexpression is considered to be constitutive and not to depend on cellular factors. Importantly, the 5’ upstream region of corAis predicted to fold into structures highly similar to the magnesium-sensing mgtA5‘ upstream region. Here using biochemical and genetic assays, we show that the intracellular concentration of magnesium ions affects corAexpression. Similarly to mgtA, we find that the effect of magnesium ions on corAexpression is mediated by the 5’ upstream region. We demonstrate that the RNA structure is important for regulation and that the Rho transcription factor is involved in the modulation of transcription termination. Consistent with previous studies, we find that translation of corL, a short ORF located within the 5’ upstream region, is important for corAregulation. Our data indicate that the efficiency of corLtranslation is inversely proportional to corAexpression, similar to what has been described for mgtAand corAin Salmonella enterica. Using a novel assay to control the import of magnesium ions, we show that while the expression of mgtAis regulated by both extra- and intracellular magnesium ions, corAis regulated by variations in intracellular magnesium ions. Our results support a model in which the expression of corAis regulated by the 5’ upstream region that senses variations of intracellular magnesium ions. |
| Databáze: |
Supplemental Index |
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