Browse
Submit Data
Databases
API
Help

Dataset Information

30 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

PG1659 functions as anti-sigma factor to extracytoplasmic function sigma factor RpoE in Porphyromonas gingivalis W83.

ABSTRACT: Anti-sigma factors play a critical role in regulating the expression of sigma factors in response to environmental stress signals. PG1659 is cotranscribed with an upstream gene PG1660 (rpoE), which encodes for a sigma factor that plays an important role in oxidative stress resistance and the virulence regulatory network of P. gingivalis. PG1659, which is annotated as a hypothetical gene, is evaluated in this study. PG1659, composed of 130 amino acids, is predicted to be transmembrane protein with a single calcium (Ca²⁺ ) binding site. In P. gingivalis FLL358 (ΔPG1659::ermF), the rpoE gene was highly upregulated compared to the wild-type W83 strain. RpoE-induced genes were also upregulated in the PG1659-defective isogenic mutant. Both protein-protein pull-down and bacterial two-hybrid assays revealed that the PG1659 protein could interact with/bind RpoE. The N-terminal domain of PG1659, representing the cytoplasmic fragment of the protein, is critical for interaction with RpoE. In the presence of PG1659, the initiation of transcription by the RpoE sigma factor was inhibited. Taken together, our data suggest that PG1659 is an anti-sigma factor which plays an important regulatory role in the modulation of the sigma factor RpoE in P. gingivalis.

SUBMITTER: Dou Y

PROVIDER: S-EPMC7940587 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Role of extracytoplasmic function sigma factor PG1660 (RpoE) in the oxidative stress resistance regulatory network of Porphyromonas gingivalis.

Project description:In Porphyromonas gingivalis, the protein PG1660, composed of 174 amino acids, is annotated as an extracytoplasmic function (ECF) sigma factor (RpoE homologue-?24). Because PG1660 can modulate several virulence factors and responds to environmental signals in P. gingivalis, its genetic properties were evaluated. PG1660 is co-transcribed with its downstream gene PG1659, and the transcription start site was identified as adenine residue 54-nucleotides upstream of the ATG translation start codon. In addition to binding its own promoter, using the purified rPG1660 and RNAP core enzyme from Escherichia coli with the PG1660 promoter DNA as template, the function of PG1660 as a sigma factor was demonstrated in an in vitro transcription assay. Transcriptome analyses of a P. gingivalis PG1660-defective isogenic mutant revealed that under oxidative stress conditions 176 genes including genes involved in secondary metabolism were downregulated more than two-fold compared with the parental strain. The rPG1660 protein also showed the ability to bind to the promoters of the highly downregulated genes in the PG1660-deficient mutant. As the ECF sigma factor PG0162 has a 29% identity with PG1660 and can modulate its expression, the cross-talk between their regulatory networks was explored. The expression profile of the PG0162PG1660-deficient mutant (P. gingivalis FLL356) revealed that the type IX secretion system genes and several virulence genes were downregulated under hydrogen peroxide stress conditions. Taken together, we have confirmed that PG1660 can function as a sigma factor, and plays an important regulatory role in the oxidative stress and virulence regulatory network of P. gingivalis.

| S-EPMC5823243 | biostudies-literature

Role of the Porphyromonas gingivalis extracytoplasmic function sigma factor, SigH.

Project description:Little is known about the regulatory mechanisms that allow Porphyromonas gingivalis to survive in the oral cavity. Here we characterize the sigma (?) factor SigH, one of six extracytoplasmic function (ECF) ? factors encoded in the P. gingivalis genome. Our results indicate that sigH expression is upregulated by exposure to molecular oxygen, suggesting that sigH plays a role in adaptation of P. gingivalis to oxygen. Furthermore, several genes involved in oxidative stress protection, such as sod, trx, tpx, ftn, feoB2 and the hemin uptake hmu locus, are downregulated in a mutant deficient in SigH designated as V2948. ECF ? consensus sequences were identified upstream of the transcriptional start sites of these genes, consistent with the SigH-dependent regulation of these genes. Growth of V2948 was inhibited in the presence of 6% oxygen when compared with the wild-type W83 strain, whereas in anaerobic conditions both strains were able to grow. In addition, reduced growth of V2948 was observed in the presence of peroxide and the thiol-oxidizing reagent diamide when compared with the W83 strain. The SigH-deficient strain V2948 also exhibited reduced hemin uptake, consistent with the observed reduced expression of genes involved in hemin uptake. Finally, survival of V2948 was reduced in the presence of host cells compared with the wild-type W83 strain. Collectively, our studies demonstrate that SigH is a positive regulator of gene expression required for survival of the bacterium in the presence of oxygen and oxidative stress, hemin uptake and virulence.

| S-EPMC3335748 | biostudies-literature

Studies of the extracytoplasmic function sigma factor PG0162 in Porphyromonas gingivalis.

Project description:PG0162, annotated as an extracytoplasmic function (ECF) sigma factor in Porphyromonas gingivalis, is composed of 193 amino acids. As previously reported, the PG0162-deficient mutant, P. gingivalis FLL350 showed significant reduction in gingipain activity compared with the parental strain. Because this ECF sigma factor could be involved in the virulence regulation in P. gingivalis, its genetic properties were further characterized. A 5'-RACE analysis showed that the start of transcription of the PG0162 gene occurred from a guanine (G) residue 69 nucleotides upstream of the ATG translation initiation codon. The function of PG0162 as a sigma factor was confirmed in a run-off in vitro transcription assay using the purified rPG0162 and RNAP core enzyme from Escherichia coli with the PG0162 promoter as template. As an appropriate PG0162 inducing environmental signal is unknown, a strain overexpressing the PG0162 gene designated P. gingivalis FLL391 was created. Compared with the wild-type strain, transcriptome analysis of P. gingivalis FLL391 showed that approximately 24% of the genome displayed altered gene expression (260 upregulated genes; 286 downregulated genes). Two other ECF sigma factors (PG0985 and PG1660) were upregulated more than two-fold. The autoregulation of PG0162 was confirmed with the binding of the rPG0162 protein to the PG0162 promoter in electrophoretic mobility shift assay. In addition, the rPG0162 protein also showed the ability to bind to the promoter region of two genes (PG0521 and PG1167) that were most upregulated in P. gingivalis FLL391. Taken together, our data suggest that PG0162 is a sigma factor that may play an important role in the virulence regulatory network in P. gingivalis.

| S-EPMC4729660 | biostudies-literature

Role of extracytoplasmic function sigma factors in biofilm formation of Porphyromonas gingivalis.

Project description:Porphyromonas gingivalis has been implicated as a major pathogen in the development and progression of chronic periodontitis. P. gingivalis biofilm formation in the subgingival crevice plays an important role in the ability of the bacteria to tolerate stress signals outside the cytoplasmic membrane. Some bacteria use a distinct subfamily of sigma factors to regulate their extracytoplasmic functions (the ECF subfamily). The objective of this study was to determine if P. gingivalis ECF sigma factors affect P. gingivalis biofilm formation.To elucidate the role of ECF sigma factors in P. gingivalis, chromosomal mutants carrying a disruption of each ECF sigma factor-encoding gene were constructed. Bacterial growth curves were measured by determining the turbidity of bacterial cultures. The quantity of biofilm growing on plates was evaluated by crystal violet staining.Comparison of the growth curves of wild-type P. gingivalis strain 33277 and the ECF mutants indicated that the growth rate of the mutants was slightly lower than that of the wild-type strain. The PGN_0274- and PGN_1740-defective mutants had increased biofilm formation compared with the wild-type (p?<?0.001); however, the other ECF sigma factor mutants or the complemented strains did not enhance biofilm formation.These results suggest that PGN_0274 and PGN_1740 play a key role in biofilm formation by P. gingivalis.

| S-EPMC4324044 | biostudies-literature

Role of an extracytoplasmic function sigma factor, PGN_0319, in hemin utilization by Porphyromonas gingivalis

Project description:Extracytoplasmic function (ECF) sigma factors are known to play an important role in the bacterial response to various environmental stresses. Porphyromonas gingivalis, a prominent etiological agent in human periodontitis, possesses six putative ECF sigma factors. So far, information is limited on an ECF sigma factor, PGN_0319. It has been recently reported that the expression of genes encoding some of the ECF sigma factors including PGN_0319 was affected by hemin availability. The aim of this study was to evaluate the role of PGN_0319 in hemin utilization by P. gingivalis. We evaluated the gene expression profile of the PGN_0319 mutant by DNA microarray, and then real-time reverse transcription PCR analysis was performed to assess genes with altered expression levels. The expressions level of hmuY and hmuR, which encode an outer-membrane protein involved in hemin utilization, and cdhR, a transcriptional regulator of hmuYR, were significantly decreased in the PGN_0319 mutant. The transcription of these genes was restored in the PGN_0319 complemented strain. We observed that the PGN_0319 mutant showed reduced growth in log phase compared with wild type under hemin-limiting condition. By electrophoretic mobility shift assay we demonstrated the recombinant PGN_0319 protein bound to the promoter region of hmuY and cdhR. In addition, we observed that PGN_0319 gene was upregulated in response to low cell density. These results demonstrate that PGN_0319 play an important role in the early growth of P. gingivalis, and directly regulates hmuYR and cdhR, thereby plays a role in the mechanisms involved in hemin utilization by P. gingivalis.

2017-01-01 | GSE78048 | GEO

Expression profiling analyses of ECF sigma factor of Porphyromonas gingivalis W83

Project description:This SuperSeries is composed of the SubSeries listed below.

2017-09-14 | GSE103839 | GEO

Expression profiling analyses of ECF sigma factor PG1660 mutant of Porphyromonas gingivalis W83

Project description:To study the expression profile of ECF sigma factor PG1660 mutant under anaerobic conditions and hydrogen peroxide stress conditions compared to the wild-type W83 by using DNA-microarray. The role of ECF sigma factor PG1660 involved in oxidative stress was published Yuetan Dou, Devon Osbourne, Rachelle McKenzie, Hansel M Fletcher. (2010) Involvement of extracytoplasmic function sigma factors in virulence regulation in Porphyromonas gingivalis W83. FEMS Microbiology Letter, 312(1):24-32.

2017-09-14 | GSE103838 | GEO

Effect of extracytoplasmic function sigma factors on autoaggregation, hemagglutination, and cell surface properties of Porphyromonas gingivalis.

Project description:Porphyromonas gingivalis is a bacterium frequently isolated from chronic periodontal lesions and is involved in the development of chronic periodontitis. To colonize the gingival crevice, P. gingivalis has to adapt to environmental stresses. Microbial gene expression is regulated by transcription factors such as those in two-component systems and extracytoplasmic function (ECF) sigma factors. ECF sigma factors are involved in the regulation of environmental stress response genes; however, the roles of individual ECF sigma factors are largely unknown. The purpose of this study was to investigate the functions, including autoaggregation, hemagglutination, gingipain activity, susceptibility to antimicrobial agents, and surface structure formation, of P. gingivalis ECF sigma factors encoded by SigP (PGN_0274), SigCH (PGN_0319), PGN_0450, PGN_0970, and SigH (PGN_1740). Various physiological aspects of the sigP mutant were affected; autoaggregation was significantly decreased at 60 min (p < 0.001), hemagglutination activity was markedly reduced, and enzymatic activities of Kgp and Rgps were significantly decreased (p < 0.001). The other mutants also showed approximately 50% reduction in Rgps activity. Kgp activity was significantly reduced in the sigH mutant (p < 0.001). No significant differences in susceptibilities to tetracycline and ofloxacin were observed in the mutants compared to those of the wild-type strain. However, the sigP mutant displayed an increased susceptibility to ampicillin, whereas the PGN_0450 and sigH mutants showed reduced susceptibility. Transmission electron microscopy images revealed increased levels of outer membrane vesicles formed at the cell surfaces of the sigP mutant. These results indicate that SigP is important for bacterial surface-associated activities, including gingipain activity, autoaggregation, hemagglutination, vesicle formation, and antimicrobial susceptibility.

| S-EPMC5607195 | biostudies-literature

Role of the extracytoplasmic function protein family sigma factor RpoE in metal resistance of Escherichia coli.

Project description:RpoE of Escherichia coli is a sigma factor of the extracytoplasmic function protein family and is required for the expression of proteins involved in maintaining the integrity of periplasmic and outer membrane components. RpoE of E. coli was needed for full resistance to Zn(II), Cd(II), and Cu(II). Promoter gene fusion and quantitative real time reverse transcription (RT)-PCR (qRT-PCR) assays demonstrated that expression of RpoE was induced by metals. Global gene expression profiles upon metal treatment of a DeltarpoE mutant strain and its wild-type strain were analyzed with microarrays, and selected genes were confirmed by qRT-PCR. The absolute number of genes that were changed in their expression upon metal stress was similar in both strains, but the increase or decrease in transcript levels upon metal treatment was smaller in the DeltarpoE mutant strain than in the wild type. Genes showing increased expression in the DeltarpoE mutant strain encoded proteins that belong to general defense systems against protein-denaturing agents. Genes showing decreased expression were part of the RpoE modulon itself plus the ompC gene, encoding a major outer membrane protein. A DeltaompC deletion strain was as sensitive to Cu(II) and Cd(II) as the DeltarpoE mutant or a DeltarpoE DeltaompC double mutant strain. In the case of Zn(II), the double mutant was more sensitive than either single mutant. This indicates that increased expression of OmpC contributes to the RpoE modulon-mediated response to metals.

| S-EPMC1065229 | biostudies-literature

Expression profiling analyses of ECF sigma factor PG0162-PG1660 mutant of Porphyromonas gingivalis W83 [RNA-Seq]

Project description:The role of ECF sigma factors PG0162, PG01660 were involved in virulence regulationin Porphyromonas gingivalis was published Yuetan Dou, Devon Osbourne, Rachelle McKenzie, Hansel M Fletcher. (2010) Involvement of extracytoplasmic function sigma factors in virulence regulation in Porphyromonas gingivalis W83. FEMS Microbiology Letter, 312(1):24-32.

2017-09-14 | GSE103739 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data