0000000001299602
AUTHOR
Birgitte H. Kallipolitis
LisRK is required for optimal fitness ofListeria monocytogenesin soil
ABSTRACTListeria monocytogenes is a food-borne pathogen responsible for the disease listeriosis. It is ubiquitously found in the environment and soil is one of its natural habitats. Listeria monocytogenes is highly capable of coping with various stressful conditions. We hypothesized that stress-responsive two-component systems such as LisRK might contribute to the adaptation of L. monocytogenes to the soil environment. Indeed, investigations of the population dynamics of wild-type and mutant strains suggest an important role of LisRK for optimal fitness of L. monocytogenes in sterile soil. Results from non-sterile soil showed that the parental strain was capable of surviving longer than mut…
The σ B -dependent regulatory sRNA Rli47 represses isoleucine biosynthesis in Listeria monocytogenes through a direct interaction with the ilvA transcript
International audience; The facultative intracellular pathogen Listeria monocytogenes can persist and grow in a diverse range of environmental conditions, both outside and within its mammalian host. The alternative sigma factor Sigma B (sigma(B)) plays an important role in this adaptability and is critical for the transition into the host. While some of the functions of the sigma(B) regulon in facilitating this transition are understood the role of sigma(B)-dependent small regulatory RNAs (sRNAs) remain poorly characterized. In this study, we focused on elucidating the function of Rli47, a sigma(B)-dependent sRNA that is highly induced in the intestine and in macrophages. Using a combinatio…
Sigma B-dependent regulatory sRNA Rli47 represses isoleucine biosynthesis in Listeria monocytogenes
International audience; Background: Small regulatory RNAs (sRNAs) can influence cellular processes by targeting mRNAs, leading to translation inhibition and mRNA degradation. Previous studies have shown that the σB-dependent sRNA Rli47 is induced in L. monocytogenes stationary phase cells, in the intestinal lumen and macrophages, but its function has remained elusive. Objectives: This study aimed to comprehensively characterize Rli47 and determine its biological function in L. monocytogenes. Methods: Besides in silico predictions, several molecular approaches such as DMS-MaPseq, northern blotting, EMSAs, RTqPCR, RNA-seq and phenotypic experiments were applied. Results: Rli47 was shown to ba…
The σB-dependent regulatory sRNA Rli47 represses isoleucine biosynthesis in Listeria monocytogenes through a direct interaction with the ilvA transcript
The facultative intracellular pathogen Listeria monocytogenes can persist and grow in a diverse range of environmental conditions, both outside and within its mammalian host. The alternative sigma factor Sigma B (σB) plays an important role in this adaptability and is critical for the transition into the host. While some of the functions of the σB regulon in facilitating this transition are understood the role of σB-dependent small regulatory RNAs (sRNAs) remain poorly characterized. In this study, we focused on elucidating the function of Rli47, a σB-dependent sRNA that is highly induced in the intestine and in macrophages. Using a combination of in silico and in vivo approaches, a binding…