Project description:The heat shock response is critical for organisms to survive at a high temperature. Heterologous expression of eukaryotic molecular chaperons protects Escherichia coli against heat stress. Here we report that expression of the plant E3 ligase BnTR1 significantly increase the thermotolerance of Escherichia coli. Different from eukaryotic chaperones, BnTR1 post-transcriptionally regulates the heat shock factor σ32 though zinc fingers of the RING domain, which interacts with DnaK resulting in stabilizing σ32 and subsequently up-regulating heat shock proteins. Our findings indicate the expression of BnTR1 confers thermoprotective effects on E. coli cells, and it may provide useful clues to engineer thermophilic bacterial strains.
Project description:The transcriptome of Escherichia coli K-12 has been widely studied over a variety of conditions for the past decade while such studies involving E. coli O157:H7, its pathogenic cousin, are just now being conducted. To better understand the impact of heat shock on E. coli O157:H7, global transcript levels of strain EDL933 cells shifted from 37°C to 50°C for 15 min were compared to cells left at 37°C using microarrays. Keywords: Stress Response
Project description:Heat-responsive and time-resolved changes in transcriptome of E. coli BL21(DE3) Experimentally mapped transcriptome structure of Escherichia coli BL21(DE3) by hybridizing total RNA (including RNA species <200 nt) to genome-wide high-density tiling arrays (60 mer probes tiled every 10 nt).
Project description:Responses of Escherichia coli W3110gyrb234 as they are upshifted to 42C Escherichia coli W3110gyrb234 cells sampled at several time points (2,5, 10, 40 min) as they are shifted to 42 C in LB, vs 0 min before upshift in LB
Project description:Recombinant Escherichia coli cultures are used to manufacture numerous therapeutic proteins and industrial enzymes, where many of these processes use elevated temperatures to induce recombinant protein production. The heat-shock response in wild-type E. coli has been well studied. In this study, the transcriptome profiles of recombinant E. coli subjected to a heat-shock and to a dual heat-shock recombinant protein induction were examined. Most classical heat-shock protein genes were identified as regulated in both conditions. The major transcriptome differences between the recombinant and reported wild-type cultures were heavily populated by hypothetical and putative genes, which indicates recombinant cultures utilize many unique genes to respond to a heat-shock. Comparison of the dual stressed culture data with literature recombinant protein induced culture data revealed numerous differences. The dual stressed response encompassed three major response patterns: induced-like, in-between, and greater than either individual stress response. Also, there were no genes that only responded to the dual stress. The most interesting difference between the dual stressed and induced cultures was the amino acid-tRNA gene levels. The amino acid-tRNA genes were elevated for the dual cultures compared to the induced cultures. Since tRNAs facilitate protein synthesis via translation, this observed increase in amino acid-tRNA transcriptome levels, in concert with elevated heat-shock chaperones, might account for improved productivities often observed for thermo-inducible systems. Most importantly, the response of the recombinant cultures to a heat-shock was more profound than wild-type cultures, and further, the response to recombinant protein induction was not a simple additive response of the individual stresses. The objective of the present work is to gain a better understanding of the heat-shock response in recombinant cultures and how this response might impact recombinant protein production. To accomplish this objective, the transcriptome response of recombinant cultures subjected to a heat-shock and a dual heat-shock recombinant protein induction were analyzed. The transcriptome levels were determined using Affymetrix E. coli Antisense DNA microarrays, such that the entire genome was evaluated. These two transcriptome responses were also compared to recombinant cultures at normal growth temperature that were not over-expressing the recombinant protein and a set of literature recombinant culture data that were chemically induced to over-express the recombinant protein. Additionally, the heat-shock response of the recombinant cultures was compared to the literature report of the heat-shock response in wild-type cultures. The results of the global transcriptome analysis demonstrated that recombinant cultures respond differently to a heat-shock stress than wild-type cultures, where the transcriptome response of the recombinant cultures is further modified by production of a recombinant protein.
Project description:Transcriptome analyses of the Escherichia coli cells acquired in the thermal adaptive evolution (Kishimoto et al, 2010, PLoS Genet) were performed. The ancestor strain (Anc) and the evolved strains (41B, 43B, 45L and 37L) were analyzed. The cells exponetially growing at the regular (37ºC) and/or evolutionary (41~45ºC) temperatures and in response to heat shock at 45ºC were collected for microarray analyses. Multiple transcriptome analyses identified the specific evolutionary direction and bias for thermal adaptation.
Project description:DNA array expression analysis comparing RNA transcripts in wild type and hho1 strains before and after a heat-shock from 25 to 37 degrees. Keywords: expression, heat shock
Project description:Escherichia coli and Staphylococcus aureus are two of the most common bacterial species responsible for severe sepsis. While it is observed that they have disparate clinical phenotypes, the signaling differences elicited by each bacteria that drive this variance remain unclear. Therefore, we utilized human whole blood exposed to heat-killed E. coli or S. aureus and measured the transcriptomic signatures. Relative to unstimulated control blood, heat-killed bacteria exposure led to significant dysregulation (up and down-regulated) of >5000 genes for each experimental condition, with a slight increase in gene dysregulation by S. aureus. While there was significant overlap regarding pro-inflammatory gene ontology pathways, heat-killed E. coli had a more considerable impact on purine metabolism than heat-killed S. aureus, which had a more significant effect on nitric oxide-mediated processes. Utilizing Ingenuity Pathway Analysis, it was predicted that nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, a main transcription factor in anti-oxidant responses, was predominately up-regulated in S. aureus relative to E. coli. Further, the use of pharmacologics that preferentially targeted the Nrf2 pathway led to differential cytokine profiles depending on the type of bacterial exposure. These findings reveal a significant inflammatory dysregulation between E. coli and S. aureus and provide insight into the potential of targeting unique pathways to curb the bacteria species-specific response.