XRE Family Transcriptional Regulator XtrSs Modulates Streptococcus Suis Fitness of Hydrogen Peroxide Stress

Abstract Streptococcus suis is an important emerging zoonosis that causes economic losses in the pig industry and severe threats to public health. Transcriptional regulators play essential roles in bacterial adaptation to host environments. In this study, we identified a novel XRE family transcriptional regulator in S. suis CZ130302, XtrSs, involved in the bacterial fitness to hydrogen peroxide stress. Based on electrophoretic mobility shift and β-galactosidase activity assays, we found that XtrSs autoregulated its own transcription and repressed the expression of its downstream gene psePs, a surface protein with unknown function in S. suis, by binding to a palindromic sequence from the promoter region. Furthermore, we proved that the deletion of the psePs gene attenuated bacterial antioxidant response. Phylogenetic analysis revealed that XtrSs and PsePs naturally co-existed as a combination in most S. suis genomes. Collectively, we demonstrated the binding characteristics of XtrSs in S. suis and provided a new insight that XtrSs played a critical role in modulating psePs to the hydrogen peroxide resistance of S. suis.

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Pseudomonas aeruginosa ExsA Regulates a Metalloprotease, ImpA, That Inhibits Phagocytosis of Macrophages

Infection and Immunity ◽

10.1128/iai.00695-19 ◽

2019 ◽

Vol 87 (12) ◽

Cited By ~ 3

Author(s):

Zhenyang Tian ◽

Sen Cheng ◽

Bin Xia ◽

Yongxin Jin ◽

Fang Bai ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Critical Role ◽

Surface Protein ◽

Host Cells ◽

Bacterial Cells ◽

Mobility Shift ◽

Content Type ◽

Direct Binding ◽

Mobility Shift Assay ◽

Opportunistic Pathogenic

ABSTRACT Pseudomonas aeruginosa is an opportunistic pathogenic bacterium whose type III secretion system (T3SS) plays a critical role in acute infections. Translocation of the T3SS effectors into host cells induces cytotoxicity. In addition, the T3SS promotes the intracellular growth of P. aeruginosa during host infections. The T3SS regulon genes are regulated by an AraC-type regulator, ExsA. In this study, we found that an extracellular metalloprotease encoded by impA (PA0572) is under the regulation of ExsA. An ExsA consensus binding sequence was identified upstream of the impA gene, and direct binding of the site by ExsA was demonstrated via an electrophoretic mobility shift assay. We further demonstrate that secreted ImpA cleaves the macrophage surface protein CD44, which inhibits the phagocytosis of the bacterial cells by macrophages. Combined, our results reveal a novel ExsA-regulated virulence factor that cooperatively inhibits the functions of macrophages with the T3SS.

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ArgR is an essential local transcriptional regulator of the arcABC operon in Streptococcus suis and is crucial for biological fitness in an acidic environment

Microbiology ◽

10.1099/mic.0.043067-0 ◽

2011 ◽

Vol 157 (2) ◽

pp. 572-582 ◽

Cited By ~ 44

Author(s):

Marcus Fulde ◽

Joerg Willenborg ◽

Astrid de Greeff ◽

Laurentiu Benga ◽

Hilde E. Smith ◽

...

Keyword(s):

Transcriptional Regulator ◽

Streptococcus Suis ◽

Arginine Deiminase ◽

Putative Virulence Factor ◽

Acidic Environment ◽

Mobility Shift ◽

Operon Expression ◽

Reporter Gene Analysis

Streptococcus suis is one of the most important pathogens in pigs and can also cause severe infections in humans. Despite its clinical relevance, very little is known about the factors that contribute to its virulence. Recently, we identified a new putative virulence factor in S. suis, the arginine deiminase system (ADS), an arginine catabolic enzyme system encoded by the arcABC operon, which enables S. suis to survive in an acidic environment. In this study, we focused on ArgR, an ADS-associated regulator belonging to the ArgR/AhrC arginine repressor family. Using an argR knockout strain we were able to show that ArgR is essential for arcABC operon expression and necessary for the biological fitness of S. suis. By cDNA expression microarray analyses and quantitative real-time RT-PCR we found that the arcABC operon is the only gene cluster regulated by ArgR, which is in contrast to the situation in many other bacteria. Reporter gene analysis with gfp under the control of the arcABC promoter demonstrated that ArgR is able to activate the arcABC promoter. Electrophoretic mobility shift assays with fragments of the arcABC promoter and recombinant ArgR, and chromatin immunoprecipitation with antibodies directed against ArgR, revealed that ArgR interacts with the arcABC promoter in vitro and in vivo by binding to a region from −147 to −72 bp upstream of the transcriptional start point. Overall, our results show that in S. suis, ArgR is an essential, system-specific transcriptional regulator of the ADS that interacts directly with the arcABC promoter in vivo.

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Molecular and Functional Characterization of One Odorant-Binding Protein Gene OBP3 in Bemisia tabaci (Hemiptera: Aleyrodidae)

Journal of Economic Entomology ◽

10.1093/jee/toz248 ◽

2019 ◽

Cited By ~ 1

Author(s):

Ran Wang ◽

Yuan Hu ◽

Peiling Wei ◽

Cheng Qu ◽

Chen Luo

Keyword(s):

Host Plant ◽

Bemisia Tabaci ◽

Binding Protein ◽

Insect Pest ◽

Critical Role ◽

Functional Characterization ◽

Odorant Binding Protein ◽

Binding Characteristics ◽

And Function ◽

Odorant Binding

Abstract Odorant binding proteins (OBPs) of insects play a critical role in chemical perceptions and choice of insect host plant. Bemisia tabaci is a notorious insect pest which can damage more than 600 plant species. In order to explore functions of OBPs in B. tabaci, here we investigated binding characteristics and function of odorant-binding protein 3 in B. tabaci (BtabOBP3). The results indicated that BtabOBP3 shows highly similar sequence with OBPs of other insects, including the typical signature motif of six cysteines. The recombinant BtabOBP3 protein was obtained, and the evaluation of binding affinities to tested volatiles of host plant was conducted, then the results indicated that β-ionone had significantly higher binding to BtabOBP3 among other tested plant volatiles. Furthermore, silencing of BtabOBP3 significantly altered choice behavior of B. tabaci to β-ionone. In conclusion, it has been demonstrated that BtabOBP3 exerts function as one carrier of β-ionone and the results could be contributed to reveal the mechanisms of choosing host plant in B. tabaci.

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iTRAQ-based quantitative proteomic analysis reveals new metabolic pathways of wheat seedling growth under hydrogen peroxide stress

PROTEOMICS ◽

10.1002/pmic.201300042 ◽

2013 ◽

Vol 13 (20) ◽

pp. 3046-3058 ◽

Cited By ~ 41

Author(s):

Pei Ge ◽

Pengchao Hao ◽

Min Cao ◽

Guangfang Guo ◽

Dongwen Lv ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Seedling Growth ◽

Proteomic Analysis ◽

Metabolic Pathways ◽

Wheat Seedling ◽

Quantitative Proteomic Analysis ◽

Peroxide Stress

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Thyroid hormones regulate phosphate homoeostasis through transcriptional control of the renal type IIa sodium-dependent phosphate co-transporter (Npt2a) gene

Biochemical Journal ◽

10.1042/bj20090671 ◽

2010 ◽

Vol 427 (1) ◽

pp. 161-169 ◽

Cited By ~ 15

Author(s):

Mariko Ishiguro ◽

Hironori Yamamoto ◽

Masashi Masuda ◽

Mina Kozai ◽

Yuichiro Takei ◽

...

Keyword(s):

Thyroid Hormone ◽

Thyroid Hormones ◽

Molecular Mechanisms ◽

Hormone Receptors ◽

Critical Role ◽

Serum Phosphate ◽

Luciferase Assay ◽

Mobility Shift ◽

Intron 1 ◽

Sodium Dependent

The type IIa renal sodium-dependent phosphate (Na/Pi) co-transporter Npt2a is implicated in the control of serum phosphate levels. It has been demonstrated previously that renal Npt2a protein and its mRNA expression are both up-regulated by the thyroid hormone T3 (3,3′,5-tri-iodothyronine) in rats. However, it has never been established whether the induction was mediated by a direct effect of thyroid hormones on the Npt2a promoter. To address the role of Npt2a in T3-dependent regulation of phosphate homoeostasis and to identify the molecular mechanisms by which thyroid hormones modulate Npt2a gene expression, mice were rendered pharmacologically hypo- and hyper-thyroid. Hypothyroid mice showed low levels of serum phosphate and a marked decrease in renal Npt2a protein abundance. Importantly, we also showed that Npt2a-deficient mice had impaired serum phosphate responsiveness to T3 compared with wild-type mice. Promoter analysis with a luciferase assay revealed that the transcriptional activity of a reporter gene containing the Npt2a promoter and intron 1 was dependent upon TRs (thyroid hormone receptors) and specifically increased by T3 in renal cells. Deletion analysis and EMSAs (electrophoretic mobility-shift assays) determined that there were unique TREs (thyroid-hormone-responsive elements) within intron 1 of the Npt2a gene. These results suggest that Npt2a plays a critical role as a T3-target gene, to control phosphate homoeostasis, and that T3 transcriptionally activates the Npt2a gene via TRs in a renal cell-specific manner.

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Sp1 mediates cell proliferation-dependent regulation of rat DNA topoisomerase IIα gene promoter

Biochemical Journal ◽

10.1042/bj3440367 ◽

1999 ◽

Vol 344 (2) ◽

pp. 367-374 ◽

Cited By ~ 7

Author(s):

Jeong Ho YOON ◽

Jeong Kee KIM ◽

Geun Bae RHA ◽

Misook OH ◽

Se-Ho PARK ◽

...

Keyword(s):

Cell Proliferation ◽

Promoter Activity ◽

Expression System ◽

Critical Role ◽

Minimal Promoter ◽

Mobility Shift ◽

Topoisomerase Iiα ◽

Dna Topoisomerase ◽

Specific Regulation ◽

Dna Topoisomerase Iiα

DNA topoisomerase IIα (topo IIα) is an essential nuclear enzyme required for chromosome segregation during mitosis. Consistent with its critical role in cell division is the fact that the expression of the gene for topo IIα is strongly regulated by the proliferation state of cells. Using a transient expression system, we determined the contribution of putative cis-acting elements in its promoter region to its basal level and cell proliferation-dependent transcription. Experiments with 5′ and/or 3′ serial deletion and site-directed mutation revealed that (1) maximal promoter activity resides in the fragment extending to position -663 bp from the ATG initiation codon, (2) minimal promoter activity is harboured at -195 bp, (3) the defined minimal promoter contains only two putative elements, inverted CCAAT box 4 (ICB4) (-166 to -162 bp) and the most proximal GC-rich box in the promoter (GC2) (-149 to -143 bp), and (4) ICB4 is most important in the basal-level transcription of the gene for rat topo IIα. The luciferase activities of the mutated reporter plasmids in G0-arrested and exponentially growing cells showed that proliferation-specific regulation is controlled mainly by GC2. Electrophoretic mobility-shift assays indicated that Sp1 binds specifically to the GC2 site. The extent of DNA-protein complex formation increases after the stimulation of cells to proliferate. These results indicate that the increased binding activity of Sp1 to GC2 is important in the up-regulation of the gene for topo IIα in growing cells.

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Streptococcus suis Induces Expression of Cyclooxygenase-2 in Porcine Lung Tissue

Microorganisms ◽

10.3390/microorganisms9020366 ◽

2021 ◽

Vol 9 (2) ◽

pp. 366

Author(s):

Muriel Dresen ◽

Josephine Schenk ◽

Yenehiwot Berhanu Weldearegay ◽

Désirée Vötsch ◽

Wolfgang Baumgärtner ◽

...

Keyword(s):

Lung Tissue ◽

Streptococcus Suis ◽

Cyclooxygenase 2 ◽

Economic Losses ◽

Biological Processes ◽

Alveolar Tissue ◽

Cox 2 ◽

Ciliated Epithelial Cells ◽

Immunohistological Analysis

Streptococcus suis is a common pathogen colonising the respiratory tract of pigs. It can cause meningitis, sepsis and pneumonia leading to economic losses in the pig industry worldwide. Cyclooxygenase-2 (COX-2) and its metabolites play an important regulatory role in different biological processes like inflammation modulation and immune activation. In this report we analysed the induction of COX-2 and the production of its metabolite prostaglandin E2 (PGE2) in a porcine precision-cut lung slice (PCLS) model. Using Western blot analysis, we found a time-dependent induction of COX-2 in the infected tissue resulting in increased PGE2 levels. Immunohistological analysis revealed a strong COX-2 expression in the proximity of the bronchioles between the ciliated epithelial cells and the adjacent alveolar tissue. The morphology, location and vimentin staining suggested that these cells are subepithelial bronchial fibroblasts. Furthermore, we showed that COX-2 expression as well as PGE2 production was detected following infection with two prevalent S. suis serotypes and that the pore-forming toxin suilysin played an important role in this process. Therefore, this study provides new insights in the response of porcine lung cells to S. suis infections and serves as a basis for further studies to define the role of COX-2 and its metabolites in the inflammatory response in porcine lung tissue during infections with S. suis.

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