Project description:This Series involves two studies: 1) The gene expression of E. coli K-12 BW25113 ompA mutant strain vs. wild type strain glasswool biofilm cells and E. coli K-12 BW25113 ompA mutant vs. wild type polystyrene biofilm cells. 2) The gene expression of E. coli BW25113 ompA/pCA24N_ompA vs. ompA/pCA24N suspension cells.
Project description:Although protein acetylation is widely observed, it has been associated with few specific regulatory functions making it poorly understood. To interrogate its functionality, we analyzed the acetylome in Escherichia coli knockout mutants of cobB, the only known sirtuin-like deacetylase, and patZ, the best-known protein acetyltransferase. For four growth conditions, more than 2,000 unique acetylated peptides, belonging to 809 proteins, were identified and differentially quantified. Nearly 65% of these proteins are related to metabolism. The global activity of CobB contributes to the deacetylation of a large number of substrates and has a major impact on physiology. Apart from the regulation of acetyl-CoA synthetase, we found that CobB-controlled acetylation of isocitrate lyase contributes to the fine-tuning of the glyoxylate shunt. Acetylation of the transcription factor RcsB prevents DNA binding, activating flagella biosynthesis and motility, and increases acid stress susceptibility. Surprisingly, deletion of patZ increased acetylation in acetate cultures, which suggests that it regulates the levels of acetylating agents. The results presented offer new insights into functional roles of protein acetylation in metabolic fitness and global cell regulation. In this study we aimed to discover how the deregulation of protein acetylation could alter physiology in E. coli. We observed that the deletion of both cobB or patZ genes in E. coli altered gene expression, specially those genes related with motility, chemotaxis and acid stress response. We used three biological replicates in this study and each condition. The control in these experiments was E. coli BW25113
Project description:Acetylation of lysine residues is conserved in all three kingdoms; however, its role in prokaryotes is unknown. Here we demonstrate that acetylation enables the reference bacterium Escherichia coli to withstand environmental stress. Specifically, the bacterium reaches higher cell densities and becomes more resistant to heat and oxidative stress when its proteins are acetylated, as shown by deletion of the gene encoding acetyltransferase YfiQ and the gene encoding deacetylase CobB, as well as by overproducing YfiQ and CobB. Furthermore, we show that the increase in oxidative stress resistance with acetylation is due to the induction of catalase activity through enhanced katG expression. We also found that two-component system proteins CpxA, PhoP, UvrY, and BasR are associated with cell catalase activity and may be responsible as the connection between bacterial acetylation and the stress response. This is the first demonstration of a specific environmental role of acetylation in prokaryotes. Overnight cultures of cobB/pCA24N-cobB and cobB/pCA24N were cultured to a turbidity of 0.05 at 600 nm and grown 2 h. Then, 0.1 mM IPTG was added for another 4 h to induce cobB expression, and then the cells were exposed to 20 mM H2O2 for 10 min. Cell pellets were collected and resuspended in RNAlater (Ambion Inc., Austin, TX), and total RNA was isolated using the RNeasy Mini Kit (Qiagen Inc., Valencia, CA). The E. coli GeneChip Genome 2.0 array (Affymetrix, P/N 900551) was used, and cDNA synthesis, fragmentation, and hybridizations were performed as described previously. If the gene with the larger transcription rate did not have a consistent transcription rate based on the 11-15 probe pairs (P-value less than 0.05), these genes were discarded. A gene was considered differentially expressed when the P-value for comparing two chips was lower than 0.05 (to assure that the change in gene expression was statistically significant and that false positives arise less than 5%) and if their fold change is higher than the standard deviation for the whole genome.
Project description:To provide more evidence of the specificity of the RNase activity of GhoS, we performed a whole-transcriptome study for the production of GhoS vs. an empty plasmid so that we could investigate all of the cellM-bM-^@M-^Ys transcripts for cleavage with GhoS, in vivo (i.e., BW25113/pCA24N-ghoS vs. BW25113/pCA24N with 1 mM IPTG induction of ghoS for 90 min). Under these conditions, only 20 genes were found to be repressed by more than 4-fold; there were no induced genes. These GhoS-repressed genes were all involved in the biosynthesis/transport of purines and pyrimidines; among them, pyrI was most highly repressed (-20 fold). These results suggest that GhoS selectively cleaves only a few cellular targets. Overnight cultures of E. coli strains BW25113-pCA24N-ghoS and BW25113-pCA24N (emtpy plasmid) were inoculated into fresh LB medium to a turbidity of 0.05 at 600 nm and grown at 37M-BM-0C. IPTG (1 mM) induction was performed when turbidity reached 0.2 and continued for 90 min. Total RNAs were isolated from the cultures and converted to cDNA for the application on E. coli genome 2.0 array.
Project description:This Series involves two studies: 1) The gene expression of E. coli K-12 BW25113 ompA mutant strain vs. wild type strain glasswool biofilm cells and E. coli K-12 BW25113 ompA mutant vs. wild type polystyrene biofilm cells. 2) The gene expression of E. coli BW25113 ompA/pCA24N_ompA vs. ompA/pCA24N suspension cells. Strains: E. coli K-12 BW25113 wild type, ompA mutant Medium: LB Cell type: Biofilm cells grown on glasswool and polystyrene surfaces Time: 15 h Temperature: 37C Strains: BW25113 ompA/pCA24N_ompA and ompA/pCA24N Medium: LB Time: 7 h Temperature: 37C Cell type: suspension cells, induced by 0.1 mM IPTG
Project description:To provide more evidence of the specificity of the RNase activity of GhoS, we performed a whole-transcriptome study for the production of GhoS vs. an empty plasmid so that we could investigate all of the cell’s transcripts for cleavage with GhoS, in vivo (i.e., BW25113/pCA24N-ghoS vs. BW25113/pCA24N with 1 mM IPTG induction of ghoS for 90 min). Under these conditions, only 20 genes were found to be repressed by more than 4-fold; there were no induced genes. These GhoS-repressed genes were all involved in the biosynthesis/transport of purines and pyrimidines; among them, pyrI was most highly repressed (-20 fold). These results suggest that GhoS selectively cleaves only a few cellular targets.
Project description:gene expression profiles by overexpressing Hha from pCA24N-hha using 2 mM IPTG induction in BW25113 wild type suspension cells in LB medium at 37C relative to BW25113 carrying the empty vector plasmid in the same test conditions. Experiment Overall Design: Strains: E. coli K12 BW25113/pCA24N, BW25113/pCA24N-hha Experiment Overall Design: Growth conditions: grow culture in LB medium at 37C to OD600 0.1 and add 2 mM IPTG to induce, and grow to OD600 0.5 to collect cells. RNA was extraction, and gene expression profiles were evaluated.
Project description:The stress effect of 100 uM sodium tetrachloropalladate (II) was evaluated in Escherichia coli K-12 BW25113 strain on the transcriptome level
Project description:Although protein acetylation is widely observed, it has been associated with few specific regulatory functions making it poorly understood. To interrogate its functionality, we analyzed the acetylome in Escherichia coli knockout mutants of cobB, the only known sirtuin-like deacetylase, and patZ, the best-known protein acetyltransferase. For four growth conditions, more than 2,000 unique acetylated peptides, belonging to 809 proteins, were identified and differentially quantified. Nearly 65% of these proteins are related to metabolism. The global activity of CobB contributes to the deacetylation of a large number of substrates and has a major impact on physiology. Apart from the regulation of acetyl-CoA synthetase, we found that CobB-controlled acetylation of isocitrate lyase contributes to the fine-tuning of the glyoxylate shunt. Acetylation of the transcription factor RcsB prevents DNA binding, activating flagella biosynthesis and motility, and increases acid stress susceptibility. Surprisingly, deletion of patZ increased acetylation in acetate cultures, which suggests that it regulates the levels of acetylating agents. The results presented offer new insights into functional roles of protein acetylation in metabolic fitness and global cell regulation. In this study we aimed to discover how the deregulation of protein acetylation could alter physiology in E. coli. We observed that the deletion of both cobB or patZ genes in E. coli altered gene expression, specially those genes related with motility, chemotaxis and acid stress response.