Por Secretion System of Porphyromonas gingivalis

Satô, Keiko

doi:10.1016/s1349-0079(11)80001-0

Cited by 8 publications

(5 citation statements)

References 26 publications

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“…We constructed single mutants in which one of the seven RR genes was disrupted by an erythromycin resistance cassette and observed their growth on a blood agar plate with enriched brain heart infusion medium (BHI). Consistent with the previous result (24), the porX deletion mutant (ΔporX mutant) produced a nonpigmented bacterial lawn (shown as beige, Fig. 1A).…”

Section: Resultssupporting

confidence: 91%

“…The P. gingivalis PorX/PorY system plays a major role in the accumulation of the iron source heme A porX null mutant of P. gingivalis 33277 strain displayed a nonpigmented phenotype due to disruption of T9SS, which subsequently reduced the accumulation of heme (24). We addressed the possibility of whether other TCSs could also influence the T9SS activity and then heme accumulation in P. gingivalis.…”

Section: Resultsmentioning

confidence: 99%

“…The PorX/PorY system is stimulated by hemin and can protect P. gingivalis cells from overloaded iron source hemin Although the PorX/PorY system contributed to the pigment phenotype of P. gingivalis for its utilization of the iron source (24), the underlying mechanism controlled by this regulatory system and associated physiological significance were not well known. We observed that the PorX/PorY system was important for P. gingivalis growth as hemin was the iron source.…”

Section: The Receiver and Effector Domains Of Porx Are Sufficient To Confer Its Function For Transcription Regulationmentioning

confidence: 99%

“…The PorX/PorY system was able to stimulate transcription of numerous genes, including many of those genes including porK , porL , porM , porN , porP , porT , and sov to encode the T9SS components ( 16 ). Consistently, a mutation at the porX locus, in a manner similar to disruption of T9SS, resulted in the accumulation of unprocessed gingipain proproteins, resulting in the reduction of Rgp and Kgp activities in bacterial cultures and a nonpigmented phenotype ( 24 ). It was once suggested that a chimeric HK-RR GppX also contributed to maturation and proper localization of gingipains to the outer membrane, thus influencing the activity of gingipains ( 25 ).…”

mentioning

confidence: 94%

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The PorX/PorY system is a virulence factor of Porphyromonas gingivalis and mediates the activation of the type IX secretion system

Yang

Jiang

Ning

et al. 2021

Journal of Biological Chemistry

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PorX/PorY is a two-component system (TCS) of Porphyromonas gingivalis that governs transcription of numerous genes including those encoding a type IX secretion system (T9SS) for gingipain secretion and heme accumulation. Here, an in vitro analysis showed that the response regulator PorX specifically bound to two regions in the promoter of porT , a known PorX-regulated T9SS gene, thus demonstrating that PorX/PorY can directly regulate specific target genes. A truncated PorX protein containing the N-terminal receiver and effector domains retained a wild-type ability in both transcription regulation and heme accumulation, ruling out the role of the C-terminal ALP domain in gene regulation. The PorX/PorY system was the only TCS essential for heme accumulation and concomitantly responded to hemin to stimulate transcription of several known PorX-dependent genes in a concentration-dependent manner. We found that PorX/PorY activated the sigH gene, which encodes a sigma factor known for P. gingivalis adaptation to hydrogen peroxide (H 2 O 2 ). Consistently, both Δ porX and Δ sigH mutants were susceptible to H 2 O 2 , suggesting a PorX/PorY-σ H regulatory cascade to confer resistance to oxidative stress. Furthermore, the Δ porX mutant became susceptible to high hemin levels that could induce oxidative stress. Therefore, a possible reason why hemin activates PorX/PorY is to confer resistance to hemin-induced oxidative stress. We also demonstrated that PorX/PorY was essential for P. gingivalis virulence because the Δ porX mutant was avirulent in a mouse model. Specifically, this TCS was required for the repression of proinflammatory cytokines secreted by dendritic cells and T cells in the P. gingivalis –infected mice.

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Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Section: The Receiver and Effector Domains Of Porx Are Sufficient To Confer Its Function For Transcription Regulationmentioning

confidence: 99%

mentioning

confidence: 94%

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The PorX/PorY system is a virulence factor of Porphyromonas gingivalis and mediates the activation of the type IX secretion system

Yang

Jiang

Ning

et al. 2021

Journal of Biological Chemistry

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“…Two of the three PorSS C-terminal domain-encoding genes (PGN_1770, PGN_0123, and PGN_2080) identified in the screen are adjacent to known pigment-or heme-affecting loci. The Por secretion system is a Bacteroides-specific secretion system that in P. gingivalis is responsible for gingipain protease secretion, and interruption of most PorSS genes leads to pigmentation defects (26). Since these PorSS C-terminal domain genes are located downstream of the previously identified pigment-affecting genes (omp28 and gppX), it is tempting to speculate that the effects on pigmentation are due to alterations in protein transport or localization.…”

Section: Discussionmentioning

confidence: 99%

Using Tn-seq To Identify Pigmentation-Related Genes of Porphyromonas gingivalis: Characterization of the Role of a Putative Glycosyltransferase

et al. 2017

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Cellular pigmentation is an important virulence factor of the oral pathogen Porphyromonas gingivalis. Pigmentation has been associated with many bacterial functions, including but not limited to colonization, maintaining a local anaerobic environment by binding oxygen molecules, and defense against reactive oxygen species (ROS) produced by immune cells. Pigmentation-associated loci identified to date have involved lipopolysaccharide, fimbriae, and heme acquisition and processing. We utilized a transposon mutant library of P. gingivalis strain ATCC 33277 and screened for pigmentation-defective colonies using massively parallel sequencing of the transposon junctions (Tn-seq) to identify genes involved in pigmentation. Transposon insertions at 235 separate sites, located in 67 genes and 15 intergenic regions, resulted in altered pigmentation: 7 of the genes had previously been shown to be involved in pigmentation, while 75 genes and intergenic regions had not. To further confirm identification, we generated a smaller transposon mutant library in P. gingivalis strain W83 and identified pigment mutations in several of the same loci as those identified in the screen in ATCC 33277 but also eight that were not identified in the ATCC 33277 screen. PGN_0361/ PG_0264, a putative glycosyltransferase gene located between two tRNA synthetase genes and adjacent to a miniature inverted-repeat transposable element, was identified in the Tn-seq screen and then verified through targeted deletion and complementation. Deletion mutations in PGN_0361/PG_0264 glycosyltransferase abolish pigmentation, modulate gingipain protease activity, and alter lipopolysaccharide. The mechanisms of involvement in pigmentation for other loci identified in this study remain to be determined, but our screen provides the most complete survey of genes involved in pigmentation to date. IMPORTANCE P. gingivalis has been implicated in the onset and progression of periodontal disease. One important virulence factor is the bacterium's ability to produce pigment. Using a transposon library, we were able to identify both known and novel genes involved in pigmentation of P. gingivalis. We identified a glycosyltransferase, previously not associated with pigmentation, that is required for pigmentation and determined its mechanism of involvement. A better understanding of the genes involved in pigmentation may lead to new insights into the complex mechanisms involved in this important virulence characteristic and could facilitate development of novel therapeutics.

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Deletion of the Riemerella anatipestifer type IX secretion system gene sprA results in differential expression of outer membrane proteins and virulence

Guo

et al. 2019

Avian Pathology

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Por Secretion System of Porphyromonas gingivalis

Cited by 8 publications

References 26 publications

The PorX/PorY system is a virulence factor of Porphyromonas gingivalis and mediates the activation of the type IX secretion system

The PorX/PorY system is a virulence factor of Porphyromonas gingivalis and mediates the activation of the type IX secretion system

Using Tn-seq To Identify Pigmentation-Related Genes of Porphyromonas gingivalis: Characterization of the Role of a Putative Glycosyltransferase

Deletion of the Riemerella anatipestifer type IX secretion system gene sprA results in differential expression of outer membrane proteins and virulence

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