Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Gene expression of Francisella tularensis LVS treated with and without Dillapiole

ABSTRACT: RNA-seq analysis was conducted on F. tularensis incubated in the presence of dillapiole. We observed a significant decrease in virulence factor expression, specifically genes under the control of the master virulence regulators MglA and SspA, compared to bacteria treated with vehicle-alone.

ORGANISM(S): Francisella tularensis

PROVIDER: GSE306100 | GEO | 2025/10/06

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Structural basis of virulence activation in Francisella tularensis

Project description:The bacterium, Francisella tularensis (Ft), is one of the most infectious agents known and classified as a category A bioweapon. Ft virulence is controlled by a unique set of transcription regulators, the MglA-SspA heterodimer, PigR, and the stress signal, ppGpp. These factors activate Francisella pathogenicity island (FPI) gene expression, which is required for virulence. MglA-SspA is expressed during infection and constitutively associates with the σ70 associated RNAP holoenzyme (RNAPσ70), indicating that RNAPσ70-(MglA-SspA) is a virulence specific polymerase. How virulence activation is mediated by these components, however, is unknown. Here we report cryo-EM structures of FtRNAPσ70, FtRNAPσ70-(MglA-SspA) and RNAPσ70-(MglA-SspA)-ppGpp-PigR complexes with promoter DNA. FtRNAPσ70-DNA and FtRNAPσ70-(MglA-SspA)-DNA structures and RT-PCR analyses show MglA-SspA stabilizes σ70 binding to DNA to regulate FPI-independent, virulence-enhancing genes. Strikingly, an Escherichia coli RNAPσ70 complex with EcSspA suggests this is a general mechanism for SspA-like regulation of bacterial RNAPσ70. Finally, our FtRNAP-σ70-(MglA-SspA)-ppGpp-PigR-DNA structure reveals that ppGpp binds to MglA-SspA to tether the DNA-binding activator, PigR, to FPI promoters. PigR in turn recruits FtRNAP CTDs to two DNA upstream (UP) elements, generating stable FPI transcription complexes. Thus, these studies unveil a novel paradigm for pathogenesis in Ft involving a virulence-specific RNAP that employs two (MglA-SspA)-based strategies to activate virulence genes.

2020-11-05 | GSE150932 | GEO

Comprehensive transposon insertion sequencing screen in Francisella tularensis LVS

Project description:We used transposon insertion sequencing (Tn-Seq) to identify the genes that are required for in vitro growth and intramacrophage growth of the live vaccine strain of F. tularensis (LVS).

2020-07-15 | GSE138658 | GEO

Francisella tularensis subsp. holarctica LVS

Project description:Ubiquitous promoter-localization of essential virulence regulators in Francisella tularensis

| PRJNA275883 | ENA

qRT-PCR on Francisella tularensis LVS and ShuS4 strain during macrophage infection

Project description:Francisella tularensis is one of three bacterial species designated as a Category A select agent by the Centre for Disease Control (CDC), a category indicating agents most likely to be employed as a biological weapon. F. tularensis can be divided into four different subspecies, and it is well known that the type, severity and duration of the disease can differ substantially depending on what subspecies is responsible for the infection. Of the four subspecies, subsp. tularensis (Type A) and subsp. holartica (Type B) are of primary clinical significance, and account for nearly all recorded incidences of the disease in humans. Though Type A is considered to be more virulent than Type B, recent reports have shown that Type A can be further sub-divided into two genetically distinct populations, termed A.I and A.II, which differ with respect to geographical location, disease outcome and source of recovered isolates. Of these two subpopulations, clinical data suggests that Type A.I strains are significantly more virulent than Type A.II, and Type A.II strains appear to have a disease outcome similar to infections with Type B. During natural infections, host mononuclear phagocytes appear to be the primary target of all F. tularensis subsp. Despite the differences in disease outcome between different subspecies, the mechanisms involved in phagosomal escape, the modulation of phagosomal biogenesis, phagosomal disruption and bacterial egress appears to be indistinguishable between subspecies, at least at a physiological level. In collaboration with Dr. Patrick McGann at Walter Reed Army Institute of Research (WRAIR) we have been studying the differential gene expression of F. tularensis during macrophage infection. Dr. McGann provided the PFGRC with RNA samples from F. tularensis strains LVS and Shuh4 isolated from infected macrophages. Samples were interrogated using high throughput qRT-PCR using 1,067 primer pairs.

2011-06-08 | GSE29755 | GEO

Microarray analysis of human monocytes infected with Francisella tularensis

Project description:Differential expression in human peripheral blood monocytes between F. novicida-infected and uninfected, and between Francisella tularensis tularensis isolate Schu S4 and uninfected. The goal was to examine genomewide transcriptional reponses to these two strains, and identify differentially-regulated genes that may help explain the virulence of Schu S4. Keywords: Immune Response, Human Monocytes, Bacteria, Francisella

2008-08-13 | GSE12108 | GEO

Transcription profiling of Francisella tularensis LVS after heat shock

Project description:Effect of temperature upshift at 44°C for 30 minutes on transcription in Francisella tularensis LVS

2009-07-01 | E-MEXP-2037 | biostudies-arrayexpress

Intra-macrophage Expression data of Francisella tularensis novicida U112

Project description:These samples are part of an experiment comparing the expression profiles of Francisella tularensis novicida grown in chemically defined medium and bacteria isolated 24 hours post infection of J774 macrophages to identify virulence factors

2017-05-02 | GSE75689 | GEO

An AraC/XylS Family Transcriptional Regulator Modulates the Oxidative Stress Response of Francisella tularensis

Project description:Francisella tularensis is a Gram-negative bacterium that causes a fatal human disease known as tularemia. The Centers for Disease Control have classified F. tularensis as Category A Tier-1 Select Agent. The virulence mechanisms of Francisella are not entirely understood. Francisella possesses very few transcription regulators, and most of these regulate the expression of genes involved in intracellular survival and virulence. The F. tularensis genome sequence analysis reveals an AraC (FTL_0689) transcriptional regulator homologous to the AraC/XylS family of transcriptional regulators. In Gram-negative bacteria, AraC activates genes required for L-arabinose utilization and catabolism. The role of the FTL_0689 regulator in F. tularensis is not known. In this study, we characterized the role of FTL_0689 in gene regulation of F. tularensis and investigated its contribution to intracellular survival and virulence. The results demonstrate that FTL_0689 in Francisella is not required for L-arabinose utilization. Instead, FTL_0689 specifically regulates the expression of the oxidative and global stress response, virulence, metabolism, and other key pathways genes required by Francisella when exposed to oxidative stress. The FTL_0689 mutant is attenuated for intramacrophage growth, and mice infected with the FTL_0689 mutant survive better than wild-type F. tularensis LVS infected mice. Based on the deletion mutant phenotype, FTL_0689 was termed osrR (oxidative stress response regulator). Altogether, this study elucidates the role of the osrR transcriptional regulator in tularemia pathogenesis.

2021-10-13 | GSE183001 | GEO

Francisella tularensis subsp. holarctica LVS

Project description:Francisella tularensis subsp. holarctica LVS Genome sequencing

| PRJNA236485 | ENA

Francisella tularensis subsp. holarctica LVS

Project description:Francisella tularensis subsp. holarctica LVS Genome sequencing

| PRJNA390943 | ENA