ChIP-seq for HrpR, HrpS, and HrpL
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ABSTRACT:
ORGANISM(S): Pseudomonas savastanoi pv. phaseolicola 1448A
PROVIDER: GSE103921 | GEO | 2018/06/30
REPOSITORIES: GEO
Similar Datasets
Project description:Pseudomonas syringae, a Gram-negative plant pathogen, infects more than 50 crops with its type III secretion system (T3SS) and causes severe economic losses around the world. Although the mechanisms of virulence-associated regulators of P. syringae T3SS have been studied for decades, the crosstalk and network underlying these regulators are still elusive. Previously, we have individually studied a group of T3SS regulators, including AefR, HrpS, and RhpRS. In the present study, we found 4 new T3SS regulator genes (envZ, ompR, tsiS and phoQ) via transposon-mediated mutagenesis. Two-component systems EnvZ and TsiS natively regulate T3SS. In order to uncover the crosstalk between 16 virulence-associated regulators, (including AefR, AlgU, CvsR, GacA, HrpL, HrpR, HrpS, MgrA, OmpR, PhoP, PilR, PsrA, RhpR, RpoN, TsiR and Vfr) in P. syringae, we mapped an intricate network named PSVnet (Pseudomonas syringae Virulence Regulatory Network) by combining differentially expression genes in RNA-seq and binding loci in ChIP-seq of all regulators.
2021-03-29 | GSE138204 | GEO
Project description:Pseudomonas syringae pv. tomato DC3000 is a model pathogen infecting tomato and Arabidopsis plants. Genes encoding the type III secretion system and substrate proteins (collectively called TTSS genes) of this bacterium are induced in plants and in minimal medium (MM). The induction of TTSS genes is mediated by HrpL, an alternative sigma factor recognizing the hrp box in the promoter of TTSS genes. The transcription of hrpL is activated by HrpR and HrpS, two homologous DNA binding proteins encoded by the hrpRS operon. Microarray analysis was conducted to evaluate the DC3000 genes regulated by hrpL and hrpRS in MM. The analysis identified a number of novel hrpLactivated genes with a putative TTSS-independent function. Genes regulated by hrpL were mostly regulated by hrpRS in the same manner, but a large number of genes regulated by hrpRS were hrpL-independent, indicating that hrpL represents one branch of the regulatory pathways downstream of hrpRS. The induction of the TTSS genes was associated with down-regulation of the house-keeping genes, indicating that the activation of the TTSS has a cost on the basic cellular activities. The novel genes/pathways identified by the microarray provide new insight into the bacterial functions coordinating with the TTSS.
2006-08-01 | GSE4848 | GEO
Project description:ChIP-seq for HrpR, HrpS, and HrpL
| PRJNA408144 | ENA
Project description:The bacterial Lon protease participates in a variety of biological processes. In Pseudomonas syringae, mutation of lon is known to activate hrpL and a few hrpL-regulated genes in the rich medium. The elevated expression of hrpL and hrpL-regulated genes results from of increased stability of HrpR, the transcriptional activator of hrpL, in the lon mutant. Here we conducted a microarray analysis to determine genes that are differently expressed in the lon- mutant of P. s. pv. tomato DC3000 grown in the rich medium KB. Most genes induced in the lon- mutant belong to the HrpL-regulon or are related to the transcription, protein synthesis, and energy metabolism. The major group of genes reduced in the lon- mutant is related to cell wall biogenesis. The HrpL-regulated genes exhibit different induction patterns in the lon- mutant, suggesting the involvement of regulators additional to HrpL in regulating these genes. Compared with the wild type bacteria, the lon- mutants exhibit elevated hrpL expression in KB medium but reduced hrpL expression in the minimal medium (MM). The reduced hrpL RNA is correlated with the reduced hrpR and hrpS RNAs, suggesting that the Lon-mediated regulation of hrpL involves different mechanisms in KB and MM. Consistent with the reduced expression of the hrpL in MM, the lon- mutants are less pathogenic on host plants. Keywords: Expression profiles of lonB mutant in KB three samples ( biological replicates) of mutation were analyzed
2007-10-14 | E-GEOD-6121 | biostudies-arrayexpress
Project description:The bacterial Lon protease participates in a variety of biological processes. In Pseudomonas syringae, mutation of lon is known to activate hrpL and a few hrpL-regulated genes in the rich medium. The elevated expression of hrpL and hrpL-regulated genes results from of increased stability of HrpR, the transcriptional activator of hrpL, in the lon mutant. Here we conducted a microarray analysis to determine genes that are differently expressed in the lon- mutant of P. s. pv. tomato DC3000 grown in the rich medium KB. Most genes induced in the lon- mutant belong to the HrpL-regulon or are related to the transcription, protein synthesis, and energy metabolism. The major group of genes reduced in the lon- mutant is related to cell wall biogenesis. The HrpL-regulated genes exhibit different induction patterns in the lon- mutant, suggesting the involvement of regulators additional to HrpL in regulating these genes. Compared with the wild type bacteria, the lon- mutants exhibit elevated hrpL expression in KB medium but reduced hrpL expression in the minimal medium (MM). The reduced hrpL RNA is correlated with the reduced hrpR and hrpS RNAs, suggesting that the Lon-mediated regulation of hrpL involves different mechanisms in KB and MM. Consistent with the reduced expression of the hrpL in MM, the lon- mutants are less pathogenic on host plants. Keywords: Expression profiles of lonB mutant in KB
2007-10-15 | GSE6121 | GEO
Project description:Background Dickeya dadantii is a necrotrophic pathogen causing disease in many plants. Previous studies have demonstrated that the type III secretion system (T3SS) of D. dadantii is required for full virulence. HrpL is an alternative sigma factor that binds to the hrp box promoter sequence of T3SS genes to up-regulate their expression. Methodology/Principal Findings To explore the inventory of HrpL-regulated genes of D. dadantii 3937 (3937), transcriptome profiles of wild-type 3937 and a hrpL mutant grown in a T3SS-inducing medium were examined. Using a cut-off value of 1.5, significant differential expression was observed in sixty-three genes, which are involved in various cellular functions such as type III secretion, chemotaxis, metabolism, regulation, and stress response. A hidden Markov model (HMM) was used to predict candidate hrp box binding sites in the intergenic regions of 3937, including the promoter regions of HrpL-regulated genes identified in the microarray assay. In contrast to biotrophic phytopathgens such as Pseudomonas syringae, among the HrpL up-regulated genes in 3937 only those within the T3SS were found to contain a hrp box sequence. Moreover, direct binding of purified HrpL protein to the hrp box was demonstrated for hrp box-containing DNA fragments of hrpA and hrpN using the electrophoretic mobility shift assay (EMSA). In this study, a putative T3SS effector DspA/E was also identified as a HrpL-upregulated gene, and shown to be translocated into plant cells in a T3SS-dependent manner. Conclusion/Significances We provide the genome-wide study of HrpL-regulated genes in a necrotrophic phytopathogen (D. dadantii 3937) through a combination of transcriptomics and bioinformatics, which led to identification of several effectors. Our study indicates the extent of differences for T3SS effector protein inventory requirements between necrotrophic and biotrophic pathogens, and may allow the development of different strategies for disease control for these different groups of pathogens. Analysis used aerobic steady state RNA from wild-type as control samples for comparison to the experimental samples of hrpL mutant taken 6 h post-inoculation in T3SS inducible minimum media. The microarray results are based on the geomean of ten normalized expression values derived from three biological replicates and two dye-swap experiments with a technology replicate for each array.
2010-10-21 | E-GEOD-17185 | biostudies-arrayexpress
Project description:Background Dickeya dadantii is a necrotrophic pathogen causing disease in many plants. Previous studies have demonstrated that the type III secretion system (T3SS) of D. dadantii is required for full virulence. HrpL is an alternative sigma factor that binds to the hrp box promoter sequence of T3SS genes to up-regulate their expression. Methodology/Principal Findings To explore the inventory of HrpL-regulated genes of D. dadantii 3937 (3937), transcriptome profiles of wild-type 3937 and a hrpL mutant grown in a T3SS-inducing medium were examined. Using a cut-off value of 1.5, significant differential expression was observed in sixty-three genes, which are involved in various cellular functions such as type III secretion, chemotaxis, metabolism, regulation, and stress response. A hidden Markov model (HMM) was used to predict candidate hrp box binding sites in the intergenic regions of 3937, including the promoter regions of HrpL-regulated genes identified in the microarray assay. In contrast to biotrophic phytopathgens such as Pseudomonas syringae, among the HrpL up-regulated genes in 3937 only those within the T3SS were found to contain a hrp box sequence. Moreover, direct binding of purified HrpL protein to the hrp box was demonstrated for hrp box-containing DNA fragments of hrpA and hrpN using the electrophoretic mobility shift assay (EMSA). In this study, a putative T3SS effector DspA/E was also identified as a HrpL-upregulated gene, and shown to be translocated into plant cells in a T3SS-dependent manner. Conclusion/Significances We provide the genome-wide study of HrpL-regulated genes in a necrotrophic phytopathogen (D. dadantii 3937) through a combination of transcriptomics and bioinformatics, which led to identification of several effectors. Our study indicates the extent of differences for T3SS effector protein inventory requirements between necrotrophic and biotrophic pathogens, and may allow the development of different strategies for disease control for these different groups of pathogens.
2010-10-21 | GSE17185 | GEO
Project description:The bacterial pathogen Erwinia amylovora is the causal agent of fire blight, an economically significant disease of apple and pear. Disease initiation by E. amylovora requires the translocation of effector proteins into host cells by the hypersensitive response and pathogenicity (hrp) type III secretion system (T3SS). The alternate sigma factor HrpL positively regulates the transcription of structural and translocated components of the T3SS via hrp promoter elements. To characterize genome-wide hrpL-dependent gene expression in E. amylovora Ea1189, wild-type and Ea1189hrpL strains were cultured in hrp-inducing minimal medium, and total RNA was compared using a custom microarray designed to represent the annotated genes of E. amylovora ATCC 49946. Results revealed 24 genes differentially-regulated in Ea1189hrpL compared to Ea1189 with fold-change expression ratios greater than 1.5; of these, the expression of 19 genes was up-regulated while five genes exhibited negative regulation. To expand our understanding of the HrpL regulon and to elucidate direct versus indirect hrpL-mediated effects on gene expression, the genome of E. amylovora ATCC 49946 was examined in silico using a hidden Markov model assembled from known Erwinia spp. hrp promoters. This technique identified 21 putative type III novel hrp promoters; of these, 8+ were validated with quantitative polymerase chain reaction based on expression analyses. In total, hrpL-regulated genes encode all known components of the hrp T3SS and 5 putative type III effectors. Eight genes displayed apparent indirect hrpL regulation suggesting that the hrpL regulon is connected to downstream signaling networks. Construction of deletion mutants of three novel hrpL-regulated genes has resulted in the identification of additional virulence factors in E. amylovora as well as mutants displaying abnormal motility and biofilm phenotypes.
2012-03-28 | E-TABM-1137 | biostudies-arrayexpress
Project description:We implemented transcriptional analysis methods using cDNA and high-throughput sequencing data to identify HrpL-regulated genes for six strains of Pseudomonas syringae
2014-01-01 | GSE46930 | GEO
Project description:We implemented transcriptional analysis methods using cDNA and high-throughput sequencing data to identify HrpL-regulated genes for six strains of Pseudomonas syringae Each Pseudomonas syringae strains was transformed with either pBAD::EV or pBAD containing native hrpL sequence. Strains were grown in MM media supplemented with arabinose and collected 1, 3, and 5 hours post arabinose treatment. RNA was extracted for each time point and mixed at a 1/3 ratio. After removal of rRNA, double stranded cDNA was generated and library prepared accordeing to Illumina protocols.
2014-01-01 | E-GEOD-46930 | biostudies-arrayexpress