Transcriptional profiling of an HtrA proteases knock-out compared to wild type
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ABSTRACT: Transcriptional profiling of an HtrA proteases knock-out compared to wild type on two different time points; logarithmic growth phase and stationary growth phase
Project description:Transcriptional profiling of an HtrA proteases knock-out compared to wild type on two different time points; logarithmic growth phase and stationary growth phase 3 Biological replicates per time point, two arrays
Project description:Transcription analysis of ΔpknK mutant (LIX11) versus wild type H37Rv during logarithmic and stationary phase growth. This will elucidate the genes regulated by PknK during transition from logarithmic growth to stationary phase growth.
Project description:Purpose: The goal of this study is to compare RNA-seq libraries of wildtype Caulobacter crescentus with two lon deletion strains (delta lon and delta lon clpX*). Methods: See Methods section of "Plasticity in AAA+ proteases reveals substrate specificity niches" for information regarding methods or contact lead correspondence. Briefly, Samples for RNAseq were extracted from wt and lon deletion strains grown to stationary phase. Conclusions: Our study represents the first detailed analysis of lon deletions (delta lon and delta lon clpX*) comparison to wt caulobacter transcriptomes, with biologic replicates, generated by RNA-seq technology in stationary phas
Project description:Specific Lactobacillus strains are marketed as probiotics i.e. health promoting organisms. As previously shown in vivo, L. plantarum WCFS1 modulates immune responses via nuclear factor (NF)kB in a growth phase dependent manner, likely caused by changed microbial cell surface characteristics. Here, we identified the differential cell-surface proteome composition of L. plantarum WCFS1 cells derived from the mid-logarithmic and late stationary growth phase by surface trypsination of intact bacterial cells, followed by a combined 1D- and 2D-LC-MS shotgun proteomics strategy, and growth phase dependent transcriptome analysis. Overall, these analyses led to the identification of 31 surface proteins differentially present in the logarithmic and stationary phase, whereas additional 17 and 33 proteins appeared solely present in stationary and logarithmic phase of growth, respectively. From 75% of predicted surface related genes displaying relatively high expression levels, the corresponding proteins were detected, demonstrating a high correlation between transcriptome and proteome profiles. The impact of cell-surface peptide fractions on cellular host responses was evaluated using NFkB promoter activation assays in intestinal epithelial cells, revealing that only late stationary phase derived peptides are capable of attenuating flagellin and cell envelope induced NFkB activation. Overall our data mechanistically expand earlier observations that revealed growth-phase dependent immunomodulation by L. plantarum WCFS1, leading to a typical adjuvant- or tolerance-like response after exposure to stationary phase harvested bacterial cells. Sub-fractionation of the late stationary phase peptide fraction revealed a sub-set of strong attenuator peptides able to manipulate NFkB related pathways to hereby attenuate pro-inflammatory signaling.
Project description:Brucellosis, an important bacterial zoonosis caused by Brucella species, has drawn increased attention around the world. As an intracellular pathogen, the ability of Brucella to deal with stress within the host cell is closely related to its virulence. The survival pressure on Brucella within a phagosome is considered similar to that during the stationary phase. Here, label-free proteomics approach was used to study the adaptive response of Brucella abortus (B. abortus) in the stationary stage. 182 down-regulated and 140 up-regulated proteins were found in the stationary-phase B. abortus. B. abortus adapted to adverse environmental changes by regulating virulence, reproduction, transcription, translation, stress response, and energy production. In addition, both logarithmic and stationary-phase B. abortus were treated with short-term starvation. The logarithmic-phase B. abortus restricted cell reproduction and energy utilization in response to nutritional stress. Additionally, the expression levels of some virulence-related proteins were identified as being significantly regulated during the transition from logarithmic to stationary phase or under starvation treatment, such as Type IV secretion system protein (T4SS), VjbR, and integration host factor (IHF). Altogether, we outlined adaptive mechanisms that B. abortus could employ during the growth and compared the differences between logarithmic and stationary-phase B. abortus in response to starvation.
Project description:In this study we report that B. melitensis at the late logarithmic phase of growth are more invasive for HeLa cells than at mid logarithmic or stationary growth phases. Microarray analysis of B. melitensis gene expression identified 414 up- and 40 down-regulated genes in late-log growth phase compared to the stationary growth phase. The vast majority of the up-regulated genes in late-log cultures were those associated with DNA replication, transcription and translation, intermediate metabolism, energy production and conversion, membrane transport and cell envelope, biogenesis and outer membrane, while the down-regulated genes were distributed among several functional categories. This first Brucella global gene expression study provides novel information on growth phase-specific gene regulation important not only for understanding Brucella physiology but also the initial molecular interactions between Brucella and its host. Keywords: Comparison bacterial growth phase normalized to genomic DNA
Project description:Expression profiles of wild type and gtaI mutant in logarithmic and stationary phase of growth. The objective was to search for differentially regulated genes potentially associated with EPS production in R. capsulatus.
Project description:Transcription analysis of M-NM-^TpknK mutant (LIX11) versus wild type H37Rv during logarithmic and stationary phase growth. This will elucidate the genes regulated by PknK during transition from logarithmic growth to stationary phase growth. Two color Experiment,Organism: Mycobacterium tuberculosis, Genotypic Technology designed Custom Mycobacterium tuberculosis H37Rv Whole Genome 8x15k GE Microarray (AMADID-26323 and AMADID-23057
Project description:<p>Enterotoxigenic <em>Escherichia coli</em> (ETEC) is a major cause of diarrhea in children and adults in endemic areas. Gene regulation of ETEC during growth <em>in vitro</em> and <em>in vivo</em> needs to be further evaluated, and here we describe the full transcriptome and metabolome of ETEC during growth from mid-logarithmic growth to early stationary phase in rich medium (LB medium). We identified specific genes and pathways subjected to rapid transient alterations in gene expression and metabolite production during the transition from logarithmic to stationary growth. The transient phase was found to be different from the subsequent induction of early stationary phase-induced genes. The transient phase was characterized by the repression of genes and metabolites involved in organic substance transport. Genes involved in fucose and putrescine metabolism were upregulated, and genes involved in iron transport were repressed. Expression of toxins and colonization factors were not changed, suggesting retained virulence from mid-logarithmic to the start of the stationary phase. Metabolomic analyses showed that the transient phase was characterized by a drop of intracellular amino acids, e.g., L-tyrosine, L-tryptophan, L-phenylalanine, L-leucine and L-glutamic acid, followed by increased levels at induction of stationary phase. A pathway enrichment analysis of the entire combined transcriptome and metabolome revealed that significant pathways during progression from logarithmic to early stationary phase are involved in the degradation of neurotransmitters aminobutyrate (GABA) and precursors of 5-hydroxytryptamine (serotonin). This work provides a comprehensive framework for further studies on transcriptional and metabolic regulation in pathogenic <em>E. coli</em>.</p>
Project description:Fis is a nucleoid-associated protein in E. coli that is abundant during early logarithmic growth in rich medium but is in short supply during stationary phase. Its role as a transcriptional regulator has been demonstrated for an increasing number of genes. In order to gain insight into the global effects of Fis on E. coli gene expression during different stages of growth in rich medium, DNA microarray analyses were conducted in fis and wild type strains during early log, mid log, late log, and stationary growth phases. We used microarrays to detail the global impact of Fis on gene expression in Escherichia coli Experiment Overall Design: E.coli cells were were grown and samples were taken at different times during growth: 90 min (early logarithmic phase), 150 min (mid-logarithmic phase), 240 min (late logarithmic phase), and 360 min (early stationary phase) for RNA extraction and hybridization on Affymetrix microarrays. This was done in triplicate and the raw data was analyzed using Microarray Analysis Suite version 5.0 (Affymetrix).