Project description:Phosphate is an essential ion for fungal growth, required for proper DNA and phospholipids biosyntesis, energetic metabolism and signal transduction. The systems for inorganic phosphate (Pi) acquisition in eukaryotic cells (PHO) have been characterized as a low-affinity (that assures a supply of Pi at normal or high external Pi concentrations) and a high-affinity (activated in response to Pi starvation). Here, as an initial step to understand the PHO pathway in A. fumigatus, we characterized the PHO80 homologue, phoB(PHO80). We showed that the delta phoB(PHO80) mutant has a severe polar growth defect and there is an interaction between PhoB(PHO80), calcineurin and calcium metabolism. Microarray hybridizations carried out with RNA obtained from wild type and delta phoB(PHO80) mutant cells showed that Afu4g03610 [phoD(PHO84)], Afu7g06350 [phoE9(PHO89)], Afu4g06020 [phoCPHO81)], and Afu2g09040 (vacuolar transporter Vtc4) were more expressed either in the delta phoB(PHO80) mutant background or in 11 mM Pi. Keywords: gene expression array-based (log2 ratio)
Project description:Phosphate is an essential ion for fungal growth, required for proper DNA and phospholipids biosyntesis, energetic metabolism and signal transduction. The systems for inorganic phosphate (Pi) acquisition in eukaryotic cells (PHO) have been characterized as a low-affinity (that assures a supply of Pi at normal or high external Pi concentrations) and a high-affinity (activated in response to Pi starvation). Here, as an initial step to understand the PHO pathway in A. fumigatus, we characterized the PHO80 homologue, phoB(PHO80). We showed that the delta phoB(PHO80) mutant has a severe polar growth defect and there is an interaction between PhoB(PHO80), calcineurin and calcium metabolism. Microarray hybridizations carried out with RNA obtained from wild type and delta phoB(PHO80) mutant cells showed that Afu4g03610 [phoD(PHO84)], Afu7g06350 [phoE9(PHO89)], Afu4g06020 [phoCPHO81)], and Afu2g09040 (vacuolar transporter Vtc4) were more expressed either in the delta phoB(PHO80) mutant background or in 0.1 mM Pi. Keywords: gene expression array-based (log2 ratio)
Project description:We used ChIP-seq to map the binding of of C-terminally FLAG3-tagged PhoB to the Escherichia coli K-12 genome during growth in MOPS minimal media with low phosphate or high phosphate (0.2 mM or 1.32 mM, respectively). As a control, we performed ChIP-seq in an untagged strain. We also used ChIP-seq to map Sigma 70 (associates with initiating RNA polymerase) binding across the E. coli K-12 genome in wild-type, ΔphoB, Δhns, and Δhns ΔphoB strains grown in low phosphate medium to determine whether PhoB modulates recruitment of RNA polymerase to promoters and whether this is modulated by H-NS.
Project description:In E. coli the phosphate homeostasis is regulated by the Pst system and the two-component system PhoB/R. Pathogens like E. coli O157:H7 are responsible for many outbreaks and can be found and survive in poor inorganic phosphate (Pi) environments. To understand global EHEC O157:H7 EDL933 strain responses to Pi-starvation, we compared the transcriptomes of EDL933 the WT strain grown in MOPS Pi rich medium and that grown in MOPS Pi poor medium, using the Affymetrix GeneChip® E. coli Genome 2.0 Array. Also we investigated the EDL933 global response to the absence of PhoB by comparing the transcriptomes of the WT strain the ΔphoB mutant both grown in Low Pi
Project description:Pathogens like E. coli O157:H7 are responsible for many outbreaks and can be found and survive in poor inorganic phosphate (Pi) environments. In E. coli the phosphate homeostasis is regulated by the Pst system and the two-component system PhoB/R. In a Δpst mutant, PhoB is constitutively activated and biofilm formation is increased. To understand how PhoB activation lead to biofilm increase, we compared the transcriptomes of EDL933 the WT strain and Δpst mutant both grown in MOPS Pi rich medium, using the Affymetrix GeneChip® E. coli Genome 2.0 Array.
Project description:In E. coli the phosphate homeostasis is regulated by the Pst system and the two-component system PhoB/R. Pathogens like E. coli O157:H7 are responsible for many outbreaks and can be found and survive in poor inorganic phosphate (Pi) environments. To understand global EHEC O157:H7 EDL933 strain responses to Pi-starvation, we compared the transcriptomes of EDL933 the WT strain grown in MOPS Pi rich medium and that grown in MOPS Pi poor medium, using the Affymetrix GeneChip® E. coli Genome 2.0 Array. Also we investigated the EDL933 global response to the absence of PhoB by comparing the transcriptomes of the WT strain the ΔphoB mutant both grown in Low Pi EDL933WT strain and its isogenic mutant ΔphoB were grown in Pi- and/or in Pi+ conditions until the OD600 reached respectively 0.55 to 0.6. Samples equal to 5.108 CFU were taken from this mid log phase and processed for transcriptomes analysis. Ten µg of RNAs were extracted and retro-transcripted. One µg of the fragmented and biotinylated cDNAs, were hybridized onto Affymetrix GeneChip® E. coli. The data were processed using the FlexArray® software; RMA normalization and the levels of transcription obtained from 3 biological replicates of each experimental condition were compared using the EB (Wright & Simon) algorithm. We then conducted comparisons between EDL933WT grown in Pi- and in Pi+ conditions (comparison A) and between EDL933WT and EDL933∆phoB strains both grown in Pi- (comparison B). The differentially expression conditions corresponded to 2-fold change (FC) cut-off and p-value < 0.05.
Project description:Comparison of transcriptional profiles of the wild-type (WT) and the phoB-mutant strain in B. fragilis strain YCH46 during phosphate (Pi) starvation. A four chip study using total RNA isolated from the WT culture and the phoB mutant culture under Pi-excess (6.6 mM) or Pi-limiting (0.0066mM) condition. Each sample contains duplicated data.
Project description:The main objective is to improve xylose fermentation by deletion of PHO80 gene in recombinant xylose-fermenting yeast strains. Microarray analysis was performed to investigate effects of PHO80 deletion on the gene expression profile of xylose-fermenting strains. Samples for 2 strains (wild-type control, PHO80-deleted strain) were taken after 6h of xylose fermentation. Each sample was triplicated, resulting in a total of 6 samples.