A third envelope stress signal transduction pathway in <i>Escherichia coli</i>

Raffa, Robert G.; Raivio, Tracy

doi:10.1046/j.1365-2958.2002.03112.x

Cited by 185 publications

(191 citation statements)

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“…Signal transduction pathways control the adaptive response to envelope stress in E. coli (10) and could influence the virulence phenotypes. We explored in this study how three different enve- lope stress responses in STEC affect Stx phage lysogenization.…”

Section: Discussionmentioning

confidence: 99%

“…Together with CpxAR, it activates spy, which encodes a periplasmic chaperone of proteins involved in envelope biogenesis (10,34). The role of BaeSR in envelope biogenesis could be linked to the up/down regulation of elements of the bacterial surface.…”

Section: Discussionmentioning

confidence: 99%

“…BaeSR is involved in cell envelope stress responses (10). These responses often result in the alteration of proteins in the cell envelope that may be involved in phage attachment to the bacterial surface.…”

Section: Role Of Envelope Stress Responses In the Generation Of Stx2 mentioning

confidence: 99%

“…CpxAR is involved in bacterial adhesion (6,7) and is activated during prophage induction in E. coli (9). Finally, BaeSR, which mediates increased resistance to toxic compounds (10), is related to envelope biogenesis (10) and could regulate the expression of surface elements (10). Moreover, BaeSR activates the promoter of the casA gene, which is part of the CRISPR/Cas response, conferring resistance against phages in bacteria and archaea (11,12).…”

mentioning

confidence: 99%

“…Moreover, BaeSR activates the promoter of the casA gene, which is part of the CRISPR/Cas response, conferring resistance against phages in bacteria and archaea (11,12). BaeSR consists of a histidine sensor kinase (BaeS) residing in the inner membrane and a response regulator (BaeR) in the cytoplasm (6,10).…”

mentioning

confidence: 99%

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BaeSR, Involved in Envelope Stress Response, Protects against Lysogenic Conversion by Shiga Toxin 2-Encoding Phages

et al. 2015

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Infection and lysogenic conversion with Shiga toxin-encoding bacteriophages (Stx phages) drive the emergence of new Shiga toxin-producing Escherichia coli strains. Phage attachment to the bacterial surface is the first stage of phage infection. Envelope perturbation causes activation of envelope stress responses in bacterial cells. Although many external factors are known to activate envelope stress responses, the role of these responses in the phage-bacterium interaction remains unexplored. Here, we investigate the link between three envelope signaling systems in E. coli (RcsBC, CpxAR, and BaeSR) and Stx2 phage infection by determining the success of bacterial lysogenic conversion. For this purpose, E. coli DH5␣ wild-type (WT) and mutant strains lacking RcsBC, CpxAR, or BaeSR signaling systems were incubated with a recombinant Stx2 phage (933W). Notably, the number of lysogens obtained with the BaeSR mutant was 5 log 10 units higher than with the WT, and the same differences were observed when using 7 different Stx2 phages. To assess whether the membrane receptor used by Stx phages, BamA, was involved in the differences observed, bamA gene expression was monitored by reverse transcription-quantitative PCR (RT-qPCR) in all host strains. A 4-fold-higher bamA expression level was observed in the BaeSR mutant than in the WT strain, suggesting that differential expression of the receptor used by Stx phages accounted for the increase in the number of lysogenization events. Establishing the link between the role of stress responses and phage infection has important implications for understanding the factors affecting lysogenic conversion, which drives the emergence of new pathogenic clones.T emperate phages are responsible for the conversion of nonpathogenic strains of bacteria to pathogenic strains by transduction of virulence genes (1). Well-known examples are Shiga toxin (Stx) phages, which carry the genes for Shiga toxin (stx). Stx phages can cause the conversion of Escherichia coli and bacteria of other genera to Shiga toxin-producing E. coli (STEC) and other Shiga-toxigenic pathogens (2). A recent example is the STEC outbreak in Germany in May 2011, where an enteroaggregative E. coli O104:H4 strain incorporated an Stx2 phage (3, 4). Because the lysogeny of E. coli by Stx phages has relevant implications for their pathogenicity, a better understanding of the molecular mechanisms underlying phage-host interaction is a challenge for researchers and could help in designing strategies to avoid lysogenization by Stx phages.The first step in phage infection is attachment to the specific receptor on the bacterial surface. The maintenance, adaptation, and protection of the bacterial envelope are essential for bacteria. Stresses that damage and alter the bacterial envelope can lead to activation of stress responses in bacteria by means of various phosphorelay signaling systems (5). In E. coli, five different envelope stress responses have been identified: BaeSR, CpxAR, RcsBC, Psp, and E (5, 6). Each response triggers a si...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Role Of Envelope Stress Responses In the Generation Of Stx2 mentioning

confidence: 99%