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Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes
Published on: September 20, 2013
A trans-acting riboswitch controls expression of the virulence regulator PrfA in Listeria monocytogenes
Edmund Loh1, Olivier Dussurget, Jonas Gripenland
1Department of Molecular Biology, Umeå University, 90187 Umeå, Sweden.
Abstract:
Riboswitches are RNA elements acting in cis, controlling expression of their downstream genes through a metabolite-induced alteration of their secondary structure. Here, we demonstrate that two S-adenosylmethionine (SAM) riboswitches, SreA and SreB, can also function in trans and act as noncoding RNAs in Listeria monocytogenes. SreA and SreB control expression of the virulence regulator PrfA by binding to the 5'-untranslated region of its mRNA. Absence of the SAM riboswitches SreA and SreB increases the level of PrfA and virulence gene expression in L. monocytogenes. Thus, the impact of the SAM riboswitches on PrfA expression highlights a link between bacterial virulence and nutrient availability. Together, our results uncover an unexpected role for riboswitches and a distinct class of regulatory noncoding RNAs in bacteria.
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