English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The AraC Negative Regulators (ANR) comprise a large family of virulence regulators distributed among diverse clinically important Gram-negative pathogens, including  Vibrio  spp.,  Salmonella  spp.,  Shigella  spp.,  Yersinia  spp.,  Citrobacter  spp., and pathogenic  E .  coli  strains. We have previously reported broad effects of the ANR members on regulators of the AraC/XylS family. Here, we interrogate possible broader effects of the ANR members on the bacterial transcriptome. Our studies focused on Aar ( A ggR- a ctivated  r egulator), an ANR family archetype in enteroaggregative  E .  coli  (EAEC) isolate 042. Transcriptome analysis of EAEC strain 042, 042 aar  and 042 aar (pAar) identified more than 200 genes that were differentially expressed (+/- 1.5 fold, p<0.05). Most of those genes are located on the bacterial chromosome (195 genes, 92.85%), and are associated with regulation, transport, metabolism, and pathogenesis, based on the predicted annotation; a considerable number of Aar-regulated genes encoded for hypothetical proteins (46 genes, 21.9%) and regulatory proteins (25, 11.9%). Notably, the transcriptional expression of three histone-like regulators, H-NS ( orf1292 ), H-NS homolog ( orf2834 ) and StpA, was down-regulated in the absence of  aar  and may explain some of the effects of Aar on gene expression. By employing a bacterial two-hybrid system, LacZ reporter assays, pull-down and electrophoretic mobility shift assay (EMSA) analysis, we demonstrated that Aar binds directly to H-NS and modulates H-NS-induced gene silencing. Importantly, Aar was highly expressed in the mouse intestinal tract and was found to be necessary for maximal H-NS expression. In conclusion, this work further extends our knowledge of genes under the control of Aar and its biological relevance  in vivo .

The AraC Negative Regulator family modulates the activity of histone-like proteins in pathogenic bacteria