Project description:We adapted thermal proteome profiling (TPP) to study the thermostability of Escherichia coli proteins in vivo. We monitored the E. coli meltome and proteome at different growth phases, in a tolC knock-out mutant and after drug treatment.
Project description:The purpose of this study is to investigate the changes of global gene expression in E. coli during an oxygen shift. All cultures were grown under aerobic or anaerobic conditions in M9 minimal media supplemented with glucose. Samples were RNA-stabilized using Qiagen RNAProtect Bacterial Reagent, and total RNA was isolated from exponentially growing cells using a Qiagen RNeasy mini kit (protocols available at www1.qiagen.com). The RNA (10 µg) was then used as the template for cDNA synthesis, the product of which was fragmented, labelled, and hybridized to an Affymetrix E. coli Antisense Genome Array, which was washed and scanned to obtain an image. All of these steps were performed according to Affymetrix protocols (available at www.affymetrix.com). This SuperSeries is composed of the following subset Series:; GSE1106: aerobic knock-out; GSE1107: anaerobic knock-out Experiment Overall Design: Refer to individual Series
Project description:In Escherichia coli, Lon is an ATP-dependent protease which degrades misfolded proteins and certain rapidly-degraded regulatory proteins. Given that oxidatively damaged proteins are generally degraded rather than repaired, we anticipated that Lon deficient cells would exhibit decreased viability during aerobic, but not anaerobic, carbon starvation. We found that the opposite actually occurs. Wild-type and Lon deficient cells survived equally well under aerobic conditions, but Lon deficient cells died more rapidly than the wild-type under anaerobiosis. Microarray analysis revealed that genes of the Clp family of ATP-dependent proteases were induced during aerobic growth but not during anaerobic growth. Thus, Clp may compensate for loss of Lon when cells are in an oxygen containing atmosphere. Under anaerobic carbon starvation conditions, Lon must be active to support survival. Keywords: Other
Project description:Escherichia coli strain MG1655 was grown to mid-log phase in defined aerobic media. One sample was treated with 30 µM CORM-3, the other sample was a control. The volume (30 ml), temperature (37oC) and shaking (200 rpm) were constant. After 15 min of exposure to CO-RM, samples were taken from treated and control cells, harvested into ice cold phenol ethanol (187 µl phenol, 3.56 ml ethanol) to stabilize RNA, and total RNA was purified using Qiagen’s RNeasy Mini kit as recommended by suppliers. RNA was quantified using a BioPhotometer (Eppendorf). Biological experiments were carried out four times, and a dye swap performed for each experiment, providing two technical repeats for each of the four biological repeats.
Project description:Mapping the occupancy of ArcA throughout the genome of Escherchia coli MG1655 K-12 using an affinity purified antibody under anaerobic and aerobic growth conditions. As a control, we also performed ChIP-chip onArcA in a ∆arcA mutant strain of Escherchia coli MG1655 K-12. Described in the manuscript The response regulator ArcA uses a diverse binding site architechture to globally regulate carbon oxidation in E. coli
Project description:A total of 4388/4385 genes' transcripts (under aerobic/microaerobic condition, respectively) were identified. Among them, 105 and 71 transcripts were confidently determined to be up- or down-regulated by more than 4 folds with false discovery rate (FDR) p value more than 1, respectively. Additionally, 49 known regulatory non-coding small RNAs (sRNAs) were detected, and 18 sRNAs were differentially abundant (more than 1.5 fold-change). Functional characterizations were revealed that the major differential expression genes were involved in (i) acid response/cation homeostasis (ex: gadAXW, and hdeAB-yhiD operons), (ii) cell adhesion/biofilm formation (ex; fimAICDFGH, and csgDEFG operons), (iii) electron transportation (ex: cydAB, and nrdHIEF operons), (iv) ion transporter (ex: efeU, and efeOB operons), (v) Iron-sulfur cluster assembly (ex: iscRSUA and sufABCDSE operons), and (vi) the undoubtable anaerobic respiration/fermentation (ex: hyaABCDEF and hybOABCDEFG operons) & aerobic respiration (ex: sdhDAB and sucABCDSE operons).