Project description:Bacterial genomes encode in many instances more than one copy of genes coding for global modulators. The enteroaggregative E. coli strain 042 encodes, in addition to the hns and stpA genes, an additional hns-like gene, hns2. We have previously determined the patterns of the H-NS2 regulation in cells grown at 37ºC by using RNA-seq (see https://doi.org/10.1128/mSystems.00220-17). In this work, we used RNA-seq to compare the transcriptome of the wt strain and its hns and hns2 derivatives grown at 25ºC in LB medium.
Project description:Bacterial genomes encode in many instances more than one copy of genes coding for global modulators. In the Enterobacteriaceae, cells express the global modulator H-NS and its paralogue StpA. The enteroaggregative E. coli strain 042 encodes, in addition to the hns and stpA genes, an additional hns gene. We used RNA-seq to compare the transcriptome of the wt strain and its hns, hns2 and double hns hns2 derivatives, as well as of an hha null mutant (hhahha2). It is well known that the Hha protein co-modulates gene expression with H-NS. The results obtained have shown that the main role of H-NS2 is to modulate a subset of H-NS modulated genes, those that also are targeted by Hha, which are mainly HGT genes. When compared with H-NS, H-NS2 also shows a differential expression level and a different regulatory pattern.
Project description:Transcriptomic study of single mutants hns, hns2 and double mutans hhahha2 and hnshns2 from enteroaggregative E. coli 042 by RNA-seq
Project description:Transcriptome analysis of two independently derived hns mutants compared to an isogenic wild-type Salmonella (strain 14028s - lab ID# WN153). Note: both the wild-type and hns strains carry an additional mutation in the rpoS locus (encoding the stationary phase sigma factor) resulting in a deletion of amino acids 61-65 that diminish its activity. Keywords: cell type comparison
Project description:Members of the H-NS protein family play a role both in the chromosome architecture and in the regulation of gene expression in bacteria. The genomes of the enterobacteria encode an H-NS paralogue, the StpA protein. StpA displays specific regulatory properties and provides a molecular backup for H-NS. Some enterobacteria also encode third H-NS paralogues. This is the case of the enteroaggregative E. coli (EAEC) strain 042, which encodes the hns, stpA and hns2 genes. We provide in this paper novel information about the role of the H-NS2 protein in strain 042. A C > T transition in the hns2 promoter leading to increased H-NS2 expression is readily selected in hns mutants. Increased H-NS2 expression partially compensates for H-NS loss. H-NS2 levels are critical for the strain 042 fitness. Under some circumstances, high H-NS2 expression levels dictated by the mutant hns2 promoter can be deleterious. The selection of T > C revertants or of clones harboring insertional inactivations of the hns2 gene can then occur. Temperature also plays a relevant role in the H-NS2 regulatory activity. At 37 °C, H-NS2 targets a subset of the H-NS repressed genes contributing to their silencing. When temperature drops to 25 °C, the repressory ability of H-NS2 is significantly reduced. At low temperature, H-NS plays the main repressory role.
Project description:We mapped the genome-wide binding of sigma 70 in E. coli K-12 MG1655 and an hns mutant that is otherwise isogenic using ChIP coupled with deep sequencing (ChIP-seq). We show that intragenic binding of sigma 70 is increased in the hns mutant.
Project description:The hns gene was deleted from WP3 genome to construct the WP3Δhns strain. The two strains were cultured at 20°C and the transcriptional profiles were compared.
Project description:The hns gene was deleted from WP3 genome to construct the WP3Δhns strain. The two strains were cultured at 4°C and the transcriptional profiles were compared.