Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The PAS domain of the Polarly-Localized Histidine Kinase FlrB in Vibrio cholerae Controls Class III Flagellar Transcription and Contributes to Intestinal Colonization

ABSTRACT: FlrB is a histidine kinase and along with FlrC it represents the two-component system that regulates flagellar transcription within Vibrio cholerae. FlrB autophosphorylates the conserved histidine at amino acid position 135, then transfers the phosphate to the conserved aspartate residue at position 54 in FlrC. FlrC-P binds promoter regions and activates sigma54-dependent transcription of class III flagellar genes. By mutating the histidine at position 135 to an asparagine (H135N), FlrB is unable to undergo autophosphorylation, prohibiting phosphorylation of FlrC and transcription of FlrC-dependent genes. Mutating the leucine residue at position 36 in the PAS domain of FlrB to a phenylalanine (L36F) results in increased FlrC-dependent transcription. We hypothesize that V. cholerae with the FlrB L36F mutant form produces significantly higher amounts of FlrC-dependent transcripts. Conversely, FlrB H135N mutants will be significantly downregulated for the same genes.

ORGANISM(S): Vibrio cholerae O395

PROVIDER: GSE302736 | GEO | 2025/08/07

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Characterization of Two Outer Membrane Proteins, FlgO and FlgP, that Influence Vibrio cholerae Motility

Project description:Vibrio cholerae is highly motile by the action of a single polar flagellum. The loss of motility reduces the infectivity of V. cholerae, demonstrating that motility is an important virulence factor. FlrC is the sigma-54-dependent positive regulator of flagellar genes. Recently, the genes VC2206 (flgP) and VC2207 (flgO) were identified as being regulated by FlrC by microarray analysis of an flrC mutant. FlgP is reported to be an outer membrane lipoprotein required for motility that functions as a colonization factor. The study reported here focuses on the characterization of flgO, the first gene in the flgOP operon. We show FlgO/P are important for motility, as these mutants have reduced motility phenotypes. The flgO/P mutant populations display fewer motile cells as well as reduced numbers of flagellated cells. The flagella produced by the flgO/P mutant strains are shorter in length than the WT flagella, which can be restored by inhibiting rotation of the flagellum. FlgO is an outer membrane protein that localizes throughout the membrane and not at the flagellar pole. Although FlgO/P do not specifically localize to the flagellum, they are required for flagellar stability. Due to the nature of these motility defects, we established that the flagellum is not sufficient for adherence, rather, motility is the essential factor required for attachment and thus colonization by V. cholerae O1 of the classical biotype. This study reveals a novel mechanism for which the OMPs FlgO and FlgP function in motility to mediate flagellar stability and influence attachment and colonization. Vibrio cholerae O395 vs. rpoN mutant

2010-05-16 | E-GEOD-17144 | biostudies-arrayexpress

Characterization of Two Outer Membrane Proteins, FlgO and FlgP, that Influence Vibrio cholerae Motility

2009-07-18 | GSE17144 | GEO

The polar flagellar transcriptional regulatory network in Vibrio campbellii deviates from known Vibrio species

Project description:Vibrio campbellii is a gram-negative bacterial pathogen that is both free-living and a pathogen of marine organisms and exhibits swimming motility via a single, polar flagellum. Swimming motility is a critical virulence factor in V. campbellii pathogenesis, and disruption of the flagellar motor significantly decreases host mortality. However, while V. campbelli encodes homologs of flagellar and chemotaxis genes conserved by other members of the Vibrionaceae, the regulatory network governing these genes have not been explored. We systematically deleted all 63 known flagellar and chemotaxis genes in V. campbellii and examined their effects on motility compared to their homologs in other Vibrios. We specifically focused on assessing the roles of the core flagellar regulators of the flagellar regulatory hierarchy established in other Vibrios: rpoN, flrA, flrC, and fliA. Although V. campbellii transcription of flagellar and chemotaxis genes is governed by a multi-tiered regulatory hierarchy similar to other Vibrios, we observed two critical differences: the σ54-dependent regulator FlrA is dispensable for motility, and Class II gene expression is independent of σ54 regulation. Our genetic and phenotypic dissection of the V. campbellii flagellar regulatory network highlights the differences that have evolved in flagellar regulation across the Vibrionaceae.

2021-07-26 | GSE167483 | GEO

Profiling oxidative stress in Saccharomyces cerevisiae by oxidation of transcription factor Swi6p

Project description:Cell cycle sensing of oxidative stress in Saccharomyces cerevisiae by oxidation of a specific cysteine residue in the transcription factor Swi6p. Yeast cells begin to bud and enter S phase when growth conditions are favourable during G1 phase. When subjected to oxidative stress, cells arrest at G1 delaying entry into the cell cycle allowing repair of cellular damage. Hence, oxidative stress sensing is coordinated with the regulation of cell cycle. We identified a redox sensing cysteine residue in the cell-cycle regulator of Saccharomyces cerevisiae, Swi6p, at position 404. Mutation of Cys404 to alanine abolished the ability of the cells to arrest at G1 upon treatment by lipid hydroperoxide. By constructing a truncated form of Swi6p, the Cys404 residue was found to be oxidised when cells were subjected to the oxidant. Furthermore, microarray analysis revealed that mutation of Cys404 to alanine led to loss of suppression of G1-cyclins CLN1 and PCL1 when the cells were exposed to lipid hydroperoxide. In conclusion, oxidation of Cys404 serves as a molecular sensor of oxidative stress and inhibits entry into the cell cycle by suppression of G1-cyclin expression. We used a gene expression approach to assess the involvement of Cys404 in oxidative stress by mutating this residue to alanine in order to study whether it contributes to Swi6p, a transcriptional factor, function for redox regulation of the cell cycle. Wild type, swi6-deletant, and swi6 C404A-mutated yeast cells were treated with either linoleic acid hydroperoxide (LoaOOH) or control. Three replicates per group/treatment.

2011-01-31 | E-GEOD-18334 | biostudies-arrayexpress

Molecular mechanisms of increased survival of Vibrio cholerae flrA mutant in amoeba

Project description:Mutation in flagellar transcriptional regulatory gene (flrA) result in increased V. cholerae growth and intracellular survival in the amoeba host Acanthamoeba castellanii. To identify molecular mechanisms behind the increased survival and growth of the flrA mutant transcriptomics assay was done.

2023-09-29 | GSE215287 | GEO

FOXC2 pH-dependent SELEX-seq

Project description:Intracellular pH (pHi) dynamics regulates diverse cell processes such as proliferation, dysplasia, and differentiation, often mediated by the protonation state of a functionally critical histidine residue in endogenous pH sensing proteins. How pHi dynamics can directly regulate gene expression and whether transcription factors can function as pH sensors has received limited attention. We tested the prediction that transcription factors with a histidine in their DNA binding domain (DBD) that forms hydrogen bonds with nucleotides can have pH-regulated activity, which is relevant to more than 85 transcription factors in distinct families, including FOX, KLF, SOX and MITF/Myc. Focusing on FOX family transcription factors, we used unbiased SELEX-seq to identify pH-dependent DNA binding motif preferences, then confirm pH-regulated binding affinities for FOXC2, FOXM1, and FOXN1 to a canonical FkhP DNA motif that are 2.5 to 7.5 greater at pH 7.0 compared with pH 7.5. For FOXC2, we also find greater activity for an FkhP motif at lower pHi in cells and that pH-regulated binding and activity are dependent on a conserved histidine (His122) in the DBD. RNA-seq with FOXC2 also reveals pH-dependent differences in enriched promoter motifs. Our findings identify pH-regulated transcription factor-DNA binding selectivity with relevance to how pHi dynamics can regulate gene expression for myriad cell behaviours.

2024-06-24 | GSE270316 | GEO

FOXC2-HIS122 and pH-dependent gene expression

2024-06-24 | GSE270232 | GEO

FOXC2 pH-dependent genome wide binding profile

2025-04-04 | GSE293822 | GEO

Interaction of CNOT3 with EBF1 regulates gene-specific transcription and mRNA stability in B lymphopoiesis

Project description:EBF1 interacts with CNOT3 and histidine 240 of EBF1 is a critical residue for this interaction. We studied H240 dependent EBF1 occupancy and gene expression regulation by genome-wide ChIP and microarray analysis. We also performed RNASeq analysis in pro-B cells to study the role of Cnot3 in early B cells development. This SuperSeries is composed of the SubSeries listed below.

2016-11-21 | GSE87637 | GEO

Position-dependent function of human sequence-specific transcription factors

Project description:Position-dependent function of human sequence-specific transcription factors

| PRJNA819990 | ENA