LysR-type transcriptional regulators (LTTRs) are emerging as key circuit components in regulating microbial stress responses and are implicated in modulating oxidative stress in the human opportunistic pathogen Pseudomonas aeruginosa. The oxidative stress response encapsulates several strategies to overcome the deleterious effects of reactive oxygen species. However, many of the regulatory components and associated molecular mechanisms underpinning this key adaptive response remain to be characterised. Comparative analysis of publically available transcriptomic datasets led to the identification of a novel LTTR, PA2206, whose expression was altered in response to a range of host signals in addition to oxidative stress. PA2206 was found to be required for tolerance to H2O2 in vitro and lethality in vivo in the Zebrafish embryo model of infection. Transcriptomic analysis in the presence of H2O2 showed that PA2206 altered the expression of 58 genes, including a large repertoire of oxidative stress and iron responsive genes, independent of the master regulator of oxidative stress, OxyR. Contrary to the classic mechanism of LysR regulation, PA2206 did not autoregulate its own expression and did not influence expression of adjacent or divergently transcribed genes. The PA2214-15 operon was identified as a direct target of PA2206 with truncated promoter fragments revealing binding to the 5-ATTGCCTGGGGTTAT-3 LysR box adjacent to the predicted -35 region. PA2206 also interacted with the pvdS promoter suggesting a global dimension to the PA2206 regulon, and suggests PA2206 is an important regulatory component of P. aeruginosa adaptation during oxidative stress.
A non-classical LysR-type transcriptional regulator PA2206 is required for an effective oxidative stress response in Pseudomonas aeruginosa.
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View SamplesMany patients with Cystic Fibrosis suffer from Gastroeosphgeal Refux Disease (GERD). This disease may lead to the aspiration of bile into the lungs. We invesigated the effect of bile on the CF lung pathogen P. aeruginosa.
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View SamplesColistin is an important cationic antimicrobial peptide (CAMP) in the fight against Pseudomonas aeruginosa infection within the cystic fibrosis (CF) lungs. The effects of sub-inhibitory colistin on gene expression in P. aeruginosa were investigated by transcriptome microarray and functional analysis. Analysis revealed an alteration in the expression of 60 genes in total from a variety of pathways. Genes associated with bacterial chronic colonisation and virulence such as response to osmotic stress, motility, and biofilm formation, as well as those associated with LPS modification and quorum sensing are the most highly represented. Most striking among these is the upregulation of the PQS biosynthesis operon including pqsH, pqsE, and the anthranilate biosynthetic genes phnAB. Early activation of this central component of the QS-network may represent a switch to a more robust population, with increased fitness in the competitive environment of the CF-lung.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Retinoic acid is essential for Th1 cell lineage stability and prevents transition to a Th17 cell program.
Specimen part
View SamplesThe IRE1 Rnase domain has been implicated in the pathology of triple negative breast cancer (TNBC), a disease with limited treatment options. The IRE1 Rnase mediates it's effects on the transcriptome via activation of the trancription factor XBP1s and via direct cleavage of mRNA through a process called RIDD. The processes through which the RNase domain contributes to TNBC is not fully understood.
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Cell line, Treatment
View SamplesBackground: Exosomes are nanovesicles of endocytic origin believed to be involved in communication between cells. Recently, it has been shown that mast cell exosomes contain RNA named "exosomal shuttle RNA". The aim of this study was to evaluate whether exosomal shuttle RNA could play a role in the communication between human mast cells and between human mast cells and human CD34 positive progenitor cells. Results: Exosomes from the human mast cell line HMC-1 contain RNA. The exosomes contain no or very little ribosomal RNA compared to their donor cells. The mRNA and microRNA content in exosomes and their donor cells was examined using microarray analyses. We found 116 microRNA in the exosomes and 134 microRNA in the cells, from which some were expressed at different level. DNA microarray experiments revealed the presence of approximately 1800 mRNAs in the exosomes, which represent 15% of the donor cell mRNA content. Transfer experiments revealed that exosomes and their RNA can transfer to other HMC-1 cells and to CD34 positive progenitors. Conclusions: To conclude, HMC-1 exosomes contain mRNA and microRNA that can be transferred to other mast cells and to CD34 progenitors. This shuttle of exosomal RNA may represent a powerful mode of communication between cells where cells send genetic information to other cells over a distance via exosomes.
Characterization of mRNA and microRNA in human mast cell-derived exosomes and their transfer to other mast cells and blood CD34 progenitor cells.
Cell line
View SamplesOverexpression lines of MYB63 and MYB63/LAC17 were generated to test hypotheses of monolignol export. Transcriptomic analysis was performed to characterize the dwarf, monolignol-glucoside containing MYB63-OX lines, as well as the MYB63/LAC17-OX lines.
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Specimen part
View SamplesCD4+ T cells differentiate into phenotypically distinct T-helper cells upon antigenic stimulation. Regulation of plasticity between these CD4+ T-cell lineages is critical for immune homeostasis and prevention of autoimmune diseases. However, the factors that regulate lineage stability are largely unknown. Here we investigate a role for retinoic acid (RA) in the regulation of lineage stability using T helper 1 (Th1) cells, traditionally considered the most phenotypically stable Th subset. We found that RA, through its receptor RARa, sustains stable expression of Th1 lineage specifying genes as well as repressing genes that instruct Th17 cell fate. RA signaling is essential for limiting Th1 cell conversion into Th17 effectors and for preventing pathogenic Th17 responses in vivo. Our studies identify RA-RARa as a key component of the regulatory network governing Th1 cell fate and define a new paradigm for the development of pathogenic Th17 cells. These findings have important implications for autoimmune diseases in which dysregulated Th1-Th17 responses are observed.
Retinoic acid is essential for Th1 cell lineage stability and prevents transition to a Th17 cell program.
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View SamplesWe systematically investigated the impact of genetic variation and the environment on protein overproduction costs in Saccharomyces cerevisiae
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Specimen part
View SamplesS. reilianum triggered loss of organ and meristem identity, and loss of meristem determinacy in male and female inflorescences and flowers. Microarray analysis showed that these developmental changes were accompanied with transcriptional regulation of genes proposed to regulate floral organ and meristem identity, and meristem determinacy in maize.
Sporisorium reilianum infection changes inflorescence and branching architectures of maize.
Specimen part, Time
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