Flagellar regulon studies
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ABSTRACT:
ORGANISM(S): Escherichia coli K-12 Escherichia coli
PROVIDER: GSE5818 | GEO | 2009/05/01
SECONDARY ACCESSION(S): PRJNA97205
REPOSITORIES: GEO
Similar Datasets
Project description:This study examined the genes under the control of FlhDC and sigmaF in E. coli. Keywords: wild-type, deletion and overexepression strains Under defined steady-state growth condition, we used two different genetic approaches to alter the modulator concentration in cells; (1) moderately expressing FlhDC or sigmaF from anhydrotetracycline (aTc) inducible and Tet repressor-controlled PLtet promoter in a plasmid-borne flhDC or fliA gene; (2) disrupting the expression of FlhDC or sigmaF in flhDC or fliA deletion mutant strains. Samples were taken from culture with wild-type or deletion strains at mid log phase (OD=0.2) or from overexpression strains at mid log phase (OD=0.2) before or 5 minutes after moderate induction. Samples were then RNA-stabilized using Qiagen RNAProtect Bacterial Reagent (Qiagen). Total RNA was then isolated using MasterPure kits (Epicentre Technologies). Purified RNA was reverse-transcribed to cDNA, labeled and hybridized to Affymetrix GeneChip E. coli Antisense Genome Arrays as recommended in the technical manual (www.affymetrix.com).
2009-05-01 | E-GEOD-5818 | biostudies-arrayexpress
Project description:Expression and use of motility genes is a potentially beneficial but costly process in bacteria. Interestingly, many isolate strains of Escherichia coli possess motility genes but have lost the ability to activate them in conditions in which motile cells are advantageous, raising the question of how they respond to these situations. Through transcriptome profiling of strains in the E. coli single-gene knockout Keio collection, we noticed drastic upregulation of motility genes in many of the deletion strains as compared to its typically non-motile parent strain (BW25113). This switch to a motile phenotype is not a direct consequence of the genes deleted, but is instead due to a variety of secondary mutations that increase the synthesis of the major motility regulator, FlhDC. We found that a phenotypic switch to motility at a population level can be induced in non-motile E. coli strains by incubation in non-shaking liquid medium overnight but not in shaking media. Individual isolates after the overnight incubation acquired distinct mutations upstream of the flhDC operon, including different insertion sequence (IS) elements and, to a lesser extent, point mutations. The rapid sweep in the non-shaking population shows that non-motile strains without existing regulatory mechanisms can quickly adapt to a motile lifestyle by quickly acquired genetic changes.
2019-07-11 | GSE129161 | GEO
Project description:Substrains in Escherichia coli K-12 MG1655 can possess various swimming motility, which is mostly resulted from different expression levels of flhDC. Here, we studied the swimming motility of two MG1655 substrains, CY562 and CY570. Our results showed that CY562 had no insertion at the promoter region of flhDC and possessed no swimming motility. In contrast, CY570 had an IS-element insertion at the promoter region of flhDC and showed a hyper-motile phenotype. Transcriptomic data suggest that expression of flhDC and the other known flagella genes was much lower in CY562 than that in CY570. Moreover, CY562 possessed higher expression levels for genes involved in stress response, especially acid-stress response, than CY570. Consistently, CY562 showed a higher survival rate under acid stress than CY570. Our data indicate that there are mechanisms conversely regulating motility and stress response in E. coli.
2021-11-15 | GSE165438 | GEO
Project description:Bacterial motility shows a strong evolvable feature depending on the environment. Hyper-motile E. coli could be isolated by evolving non-motile E. coli due to the mutations that enhanced transcriptional expression of the master regulator of the flagellum biosynthesis, FlhDC. These hyper-motile isolates showed reduced growth fitness but with the molecular mechanisms unrevealed. Here we obtained a novel type of hyper-motile isolates by evolving a weakly-motile E. coli K12 strain on the soft agar plates. These isolates carried high accumulated FlhDC proteins and they shared one single point mutation of ClpXV78F. The V78F affected the ATP binding to ClpX via steric repulsive effect and the mutated ClpXP protease lost most of its ability to degraded FlhDC and some other of its known targets. The signal tag of FlhDC for ClpXP recognition was also characterized. Intriguingly, in the hyper-motile strains, the highly enhanced expression of the motility genes was accompanied by the reduced expression of stress resistance genes relating to the reduced fitness of these isolates. Hence, ClpX appeared to be a novel and hot locus during the evolution of bacterial motility and the molecular mechanism of the trade-off between motility and growth was proposed for the first time.
2021-11-25 | PXD023645 | Pride
Project description:Bacterial motility shows a strong evolvable feature depending on the environment. Hyper-motile E. coli could be isolated by evolving non-motile E. coli due to the mutations that enhanced transcriptional expression of the master regulator of the flagellum biosynthesis, FlhDC. These hyper-motile isolates showed reduced growth fitness but with the molecular mechanisms unrevealed. Here we obtained a novel type of hyper-motile isolates by evolving a weakly-motile E. coli K12 strain on the soft agar plates. These isolates carried high accumulated FlhDC proteins and they shared one single point mutation of ClpXV78F. The V78F affected the ATP binding to ClpX via steric repulsive effect and the mutated ClpXP protease lost most of its ability to degraded FlhDC and some other of its known targets. The signal tag of FlhDC for ClpXP recognition was also characterized. Intriguingly, in the hyper-motile strains, the highly enhanced expression of the motility genes was accompanied by the reduced expression of stress resistance genes relating to the reduced fitness of these isolates. Hence, ClpX appeared to be a novel and hot locus during the evolution of bacterial motility and the molecular mechanism of the trade-off between motility and growth was proposed for the first time.
2021-11-15 | GSE165151 | GEO
Project description:Expression profiling of wild type and purR deletion strains of E. coli K-12 MG1655 under both M9 minimal media and addition of adenine.
2011-06-14 | GSE26588 | GEO
Project description:Many neutralophilic bacterial species try to evade acid stress with an escape strategy, which is reflected in the increased expression of genes coding for flagellar components. Extremely acid-tolerant bacteria, such as Escherichia coli, survive the strong acid stress, e.g. in the stomach of vertebrates. Recently, we were able to show that the induction of motility genes in E. coli is strictly dependent on the degree of acid stress, i.e. they are induced under mild acid stress but not under severe acid stress. However, it was not known to what extent fine-tuned expression of motility genes is related to fitness and the ability to survive periods of acid shock. In this study, we demonstrate that the expression of FlhDC, the master regulator of flagellation, is inversely correlated with acid shock survival of E. coli. We encountered this phenomenon when analyzing mutants from the Keio collection in which the expression of flhDC was altered by an IS element. These results suggest a fitness trade-off between acid tolerance and motility.
2024-04-14 | GSE260455 | GEO
Project description:Total proteome analysis data for ABC-F (YheS, YbiT, EttA, and Uup) deletion strains in Escherichia coli.
2024-04-26 | PXD049710 | JPOST Repository
Project description:The use of whole genome microarrays for monitoring mutagenised or otherwise engineered genetic derivatives is a potentially powerful tool for checking genomic integrity. Using comparative genomic hybridization of a number of unrelated, directed deletion mutants in Escherichia coli K-12 MG1655 we identified unintended secondary genomic deletions in the flhDC region in fnr, crp, and creB mutants. These deletions were confirmed by PCR and phenotypic tests. Our findings show that non-motile progeny are found in some populations of MG1655 directed deletion mutants, and studies on the effects of gene knock-outs should be viewed with caution when the mutants have not been screened for the presence of secondary deletions, or confirmed by other methods. We used the CGH method to genetically characterize a series of regulatory gene deletion mutants we had made in MG1655 using the lamda-Red method of Datsenko and Wanner. A number of strains were tested using CGH, and each strain was tested only once. Genomic DNA isolated from wt MG1655 was used as a reference in all hybridisations.
2007-09-30 | E-GEOD-7695 | biostudies-arrayexpress
Project description:Expression profiling of wild type and purR deletion strains of E. coli K-12 MG1655 under both M9 minimal media and addition of adenine. An eight chip study with two different strains under two separate culture conditions.
2011-06-14 | E-GEOD-26588 | biostudies-arrayexpress