Investigating the new role of FlhF identifies novel interactions with genes involved in flagellar synthesis in Campylobacter jejuni
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ABSTRACT:
PROVIDER: PRJEB34440 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| ERR3523190_1.fastq.gz | Fastqsanger.gz | |||
| ERR3523190_2.fastq.gz | Fastqsanger.gz | |||
| ERR3523191_1.fastq.gz | Fastqsanger.gz | |||
| ERR3523191_2.fastq.gz | Fastqsanger.gz | |||
| ERR3523192_1.fastq.gz | Fastqsanger.gz |
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Project description:DksA is well-known for its regulatory role in the transcription of ribosomal RNA and genes involved in amino acid synthesis in many bacteria. DksA is also reported to control expression of virulence genes in pathogenic bacteria. Here, we elucidated the roles of the DksA-like protein (CJJ81176_0160, Cj0125c) in the pathogenesis of Campylobacter jejuni. Like in other bacteria, transcription of stable RNA was repressed by DksA under stressful conditions in C. jejuni. Transcriptomic and proteomic analyses of C. jejuni 81-176 and its isogenic dksA mutant showed differential expression of many genes involved in iron-related metabolism, flagellar synthesis and amino acid metabolism. Also the dksA mutant of C. jejuni demonstrated a decreased ability to invade into intestinal cells and to induce release of interleukin-8 from intestinal cells. These results suggest the DksA-like protein plays an important regulatory role in the physiology and virulence of C. jejuni. Keywords: dksA mutation of Campylobacter jejuni
2008-05-06 | GSE9866 | GEO
Project description:Surface appendages such as flagella and type IV pili mediate a broad range of bacterial behaviors including motility, attachment, and surface sensing. While many species harbor both flagella and type IV pili, little is known about how or if their synthesis is coupled. Here, we show that deletions of genes encoding different flagellum machinery components result in a reduction of pilus synthesis in Caulobacter crescentus. First, we show that different flagellar mutants exhibit different levels of sensitivity to a pilus-dependent phage and that less cells within populations of flagellar mutants make pili. Furthermore, we find that single cells within flagellar mutant populations produce less pili per cell. We demonstrate that these gene deletions result in reduced transcription of pilus-associated genes and have a broad effect on global transcription profiles. Finally, we show that the decrease in pilus production is due to a reduction in the pool of pilin subunits that are polymerized into pilus fibers. These data demonstrate that mutations in flagella gene components affect not only motility but can also have considerable and unexpected consequences on other aspects of cell biology.
2019-07-05 | GSE126478 | GEO
Project description:Flagellar mutants have reduced pilus synthesis in Caulobacter crescentus
| PRJNA522031 | ENA
Project description:FlhF is a key protein required for complete flagellar synthesis, and its deletion results in the complete absence of a flagella and thus motility in Campylobacter jejuni. However, the specific mechanism still remains unknown. In this study, RNA-Seq, EMSAs, ChIP-qPCR and β-Galactosidase assays were performed to elucidate the novel interactions between FlhF and genes involved in flagellar synthesis. Results showed that FlhF has an overall influence on the transcription of flagellar genes with an flhF mutant displaying down-regulation of most flagellar related genes. FlhF can directly bind to the flgI promoter to regulate its expression, which has significant expression change in an flhF mutant. The possible binding site of FlhF to the flgI promoter was explored by continuously narrowing the flgI promoter region and performing further point mutations. Meanwhile, FlhF can directly bind to the promoters of rpoD, flgS, and fliA encoding early flagellin regulators, thereby directly or indirectly regulating the synthesis of class I, II, and III flagellar genes, respectively. Collectively, this study demonstrates that FlhF may directly regulate the transcription of flagellar genes by binding to their promoters as a transcriptional regulator, which will be helpful in understanding the mechanism of FlhF in flagellar biosynthetic and bacterial flagellation in general.
| S-EPMC7105676 | biostudies-literature
Project description:We examined two variants of the genome-sequenced strain, Campylobacter jejuni NCTC11168, which show marked differences in their virulence properties including colonization of poultry, invasion of Caco-2 cells, and motility. Transcript profiles obtained from whole genome DNA microarrays and proteome analyses demonstrated that these differences are reflected in late flagellar structural components and in virulence factors including those involved in flagellar glycosylation, and cytolethal distending toxin production. We identified putative s28 and s54 promoters for many of the affected genes, and found that greater differences in expression were observed for s28-controlled genes. Inactivation of the gene encoding s28, fliA, resulted in an unexpected increase in transcripts with s54 promoters, as well as decreased transcription of s28-regulated genes. This was unlike the transcription profile observed for the attenuated C. jejuni variant, suggesting that the reduced virulence of this organism was not entirely due to impaired function of s28. However, inactivation of flhA, an important component of the flagellar export apparatus, resulted in expression patterns similar to that of the attenuated variant. These findings indicate that the flagellar regulatory system plays an important role in campylobacter pathogenesis and that flhA is a key element involved in the coordinate regulation of late flagellar genes and of virulence factors in C. jejuni. Furthermore, we provide a model for flagellar regulation, which forms a foundation for the study of the unique regulatory networks in this important human pathogen. Keywords: parallel sample
2004-03-03 | GSE708 | GEO
Project description:DksA is well-known for its regulatory role in the transcription of ribosomal RNA and genes involved in amino acid synthesis in many bacteria. DksA is also reported to control expression of virulence genes in pathogenic bacteria. Here, we elucidated the roles of the DksA-like protein (CJJ81176_0160, Cj0125c) in the pathogenesis of Campylobacter jejuni. Like in other bacteria, transcription of stable RNA was repressed by DksA under stressful conditions in C. jejuni. Transcriptomic and proteomic analyses of C. jejuni 81-176 and its isogenic dksA mutant showed differential expression of many genes involved in iron-related metabolism, flagellar synthesis and amino acid metabolism. Also the dksA mutant of C. jejuni demonstrated a decreased ability to invade into intestinal cells and to induce release of interleukin-8 from intestinal cells. These results suggest the DksA-like protein plays an important regulatory role in the physiology and virulence of C. jejuni. Keywords: dksA mutation of Campylobacter jejuni The design utilized a commercially available two color microarray slide for the enture transcriptome of Campylobacter jejuni. Six hybridizations were performed each with independently extracted samples of either C. jejuni wildtype of C. jejuni dksA mutant cDNA samples. A dye swap was utilized to help minimize dye dependent bias. Thus there were six biological replicates of each sample.
2008-05-05 | E-GEOD-9866 | biostudies-arrayexpress
Project description:Major foodborne bacterial pathogens, such as Campylobacter jejuni, have devised complex strategies to establish and foster intestinal infections. For more than two decades researchers have used immortalized cell lines derived from human intestinal tissue to dissect C. jejuni-host cell interactions. Known from these studies is that C. jejuni virulence is multifactorial, requiring a coordinated response to produce virulence factors that facilitate the bacterium’s host-cell interactions. This study was initiated to identify C. jejuni proteins that contribute to adaptation to the host cell environment and cellular invasion. We demonstrated that C. jejuni responds to INT 407 and Caco-2 cells in a similar fashion at the cellular and molecular levels. Active protein synthesis was found to be required for C. jejuni to maximally invade these host cells. Proteomic and transcriptomic approaches were then used to define the protein and gene expression profiles of C. jejuni co-cultured with cells. By focusing on those genes showing increased expression by C. jejuni when co-cultured with epithelial cells, we discovered that C. jejuni quickly adapts to co-culture with epithelial cells by synthesizing gene products that enable it to acquire specific amino acids for growth, scavenge for inorganic molecules including iron, resist reactive oxygen/nitrogen species, and promote bacteria-host cell interactions. Based on these findings, we selected a subset of the genes involved in chemotaxis and the regulation of flagellar assembly and generated C. jejuni deletion mutants for phenotypic analysis. Binding and internalization assays revealed significant differences in the interaction of C. jejuni chemotaxis and flagellar regulatory mutants. The identification of genes involved in C. jejuni adaptation to culture with host cells provides new insights into the infection process.
2019-04-11 | GSE114909 | GEO
Project description:Cj0440c encodes a putative transcriptional regulator. To determine the role of Cj0440c in C.jejuni, we knocked out Cj0440c in the wild-type strain (S) to obtain the Cj0440c mutants (SM). Then we compared the transcriptome of the Cj0440c mutant with that of the parent strain using DNA microarray. These comparisons identified 19 genes that showed aM-bM-^IM-%2-fold change in expression in SM. The differentially expressed genes in SM encode proteins involved in flagellar biosynthesis, O-linked glycosylation and hypothetical proteins with unknown fuctions. Cj0440c may regulate flagellar structural element expression or as a compenent of flagellar complex co-expressed with other flagellar genes. Subsequent experiments demonstrated that inactivation of Cj0440c affected corresponding phenotypes of C.jejuni, including broken flagella, weaker motility and reduced colonization ability in chickens. These findings indicate that Cj0440c governs the expression of multiple genes related to flagellar biosynthesis and O-linked glycosylation. This study provides favorable evidence for completing the information of the Campylobacter jejuni genome. An eight chip study using total RNA recoverd from four separate wild-type cultures of Campylobacter jejuni NCTC111168 (S) and four separate cultures of a mutant strain, Campylobacter jejuni NCTC11168 delta- Cj0440c (SM), in which Cj0440c is deleted. Each chip measures the expression level of 1634 genes from Campylobacter jejuni NCTC11168.
2013-08-13 | E-GEOD-49256 | biostudies-arrayexpress
Project description:Campylobacter jejuni produces a single flagellum on one or both poles of the cell, the polar flagella not only confer the bacterium darting motility but also involved in its virulence and metabolic processes. FlhF is a lately defined flagella biosynthesis regulator, but how it regulates flagella assembly isn’t clear at present. Previous research had indicated FlhF was associated with gene expression, to understanding its role in flagella system and its correlation with C. jejuni virulence, the global gene expression profiles of C. jejuni NCTC 11168 after inactivation of FlhF was analyzed. Transcriptome analysis revealed that ten genes were significantly differentially expressed with 6 down-regulated and 4 up-regulated, these genes are involved in diverse cellular functions including bacterial chemotaxis, flagellar assembly and two-component system, significance analysis revealed that the pathway of flagellar assembly was remarkable affected. Further studies were focused on the flagella system, FlhF was found play a global role as 63% (41/65) of the flagella genes were down-regulated, it influences flagella gene transcription from the early stage, this effect persists during the synthesis process and has a remarkable impact on the late part. The results above expand our cognition of this regulator, and also helpful for comprehensively and systematically reveal its role in flagella system.
2018-10-03 | GSE87852 | GEO
Project description:Cj0440c, a putative transcriptional regulator, was over-expressed in the high-level erythromycin-resistant (Eryr) Campylobacter jejuni strains. To determine the role of Cj0440c on the development and fitness of erythromycin resistance in C. jejuni, we knocked out Cj0440c in Eryr strain (R) to obtain the Cj0440c mutants (RM). Then we compared the transcriptome of the Cj0440c mutant with that of the parent strain using DNA microarray. These comparisons identified 9 genes that showed a ≥2-fold change in expression in RM. The differentially expressed genes in RM are related to flagellar biosynthesis and unknown functions. What's more, katA, encoding catalase, down-regulated in RM. Cj0440c may progress flagellar genes expression, help to escape drug pressure and disseminate and colonize smoothly, and Cj0440c in Eryr Campylobacter may protect bacteria from harmful oxygen stress from the host immune system, other microorganism in host intestinal and its own products. These findings indicate that Cj0440c is essential for the fitness (growth) of resistant C. jejuni by controlling the expression of several genes involved in flagellar assembly and catalase, enhancing cell motility for colonization and invasion under the pressure of drug. This study widened our understanding on the molecular mechanism of resistance and provides scientific reference for drug research and application.
2013-08-13 | GSE49255 | GEO