Transcriptional Profiles of Treponema denticola in Response to Environmental Conditions

Mchardy, Ian Howard; Keegan, Caroline; Sim, Jee Hyun; Shi, Wenyuan; Lux, Renate

doi:10.1371/journal.pone.0013655

Cited by 16 publications

(31 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The increased sensitivity of the Td 1078 M strain to air-saturated medium relative to the wild-type strain together with the efficient steady-state O 2 R activity for the isolated enzyme supports an O 2 -scavenging function for Td FDP in the likely sub-aerobic but fluctuating O 2 levels of the periodontal environment [5, 9]. A previous study did not observe upregulation of the FDP gene (TDE1078) transcription upon exposure of Td to air [9]. Our Western blotting (Fig.…”

Section: Resultsmentioning

confidence: 95%

“…Rds and Rd-like proteins can serve as efficient proximal electron donor to FDPs [24, 30, 37]. The Td genome encodes a single Rd gene, and its transcription was shown to be upregulated upon exposure of Td to dioxygen [9]. Although a Td NROR has not been characterized, a gene (TDE0096) encoding a homologous putative NADH oxidoreductase has been identified [7].…”

Section: Resultsmentioning

confidence: 99%

“…S3) and a previous proteomics study [51] instead showed constitutive expression of the FDP in T. denticola under anaerobic growth conditions. This constitutive expression could function as a pre-emptive defense in contrast to other oxidative stress protection enzymes, which are upregulated upon exposure of T. denticola to air [9]. FDPs could provide oxidative stress protection in many other oral bacteria.…”

Section: Resultsmentioning

confidence: 99%

“…Td is able to survive the redox stressful periodontal environment despite the absence of genes encoding classical superoxide dismutases or catalases in its genome [6, 7]. The Td genome does, however, encode homologs of peroxiredoxin and superoxide reductase [7, 8], and the transcripts for these two oxidative stress protection enzymes were shown to be upregulated upon exposure of Td to air [9]. Some of the authors recently showed that the superoxide reductase does indeed protect Td against intracellular superoxide generation [10].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Dioxygen and nitric oxide scavenging by Treponema denticola flavodiiron protein: a mechanistic paradigm for catalysis

et al. 2015

View full text Add to dashboard Cite

Flavodiiron proteins (FDPs) contain a unique active site consisting of a non-heme diiron carboxylate site proximal to a flavin mononucleotide (FMN). FDPs serve as the terminal components for reductive scavenging of dioxygen (to water) or nitric oxide (to nitrous oxide), which combats oxidative or nitrosative stress in many bacteria. Characterizations of FDPs from spirochetes or from any oral microbes have not been previously reported. Here, we report characterization of an FDP from the anaerobic spirochete, Treponema (T.) denticola, which is associated with chronic periodontitis. The isolated T. denticola FDP exhibited efficient four-electron dioxygen reductase activity and lower but significant anaerobic nitric oxide reductase activity. A mutant T. denticola strain containing the inactivated FDP-encoding gene was significantly more air-sensitive than the wild-type strain. Single turnover reactions of the four-electron-reduced FDP (FMNH2–FeIIFeII) (FDPred) with O2 monitored on the milliseconds to seconds time scale indicated initial rapid formation of a spectral feature consistent with a cis-μ-1,2-peroxo-diferric intermediate, which triggered two-electron oxidation of FMNH2. Reaction of FDPred with NO showed apparent cooperativity between binding of the first and second NO to the diferrous site. The resulting diferrous dinitrosyl complex triggered two-electron oxidation of the FMNH2. Our cumulative results on this and other FDPs indicate that smooth two-electron FMNH2 oxidation triggered by the FDPred/substrate complex and overall four-electron oxidation of FDPred to FDPox constitutes a mechanistic paradigm for both dioxygen and nitric oxide reductase activities of FDPs. Four-electron reductive O2 scavenging by FDPs could contribute to oxidative stress protection in many other oral bacteria.

show abstract

Section: Resultsmentioning

confidence: 95%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Dioxygen and nitric oxide scavenging by Treponema denticola flavodiiron protein: a mechanistic paradigm for catalysis

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Reverse transcription was performed using Superscript III (Invitrogen, NY, USA) as described previously [6]. RNA was hydrolyzed in the presence of 0.1 M EDTA and 0.2 N NaOH at 65°C for 10 mins.…”

Section: Methodsmentioning

confidence: 99%

Transcriptional Responses of Treponema denticola to Other Oral Bacterial Species

et al. 2014

Self Cite

View full text Add to dashboard Cite

The classic organization by Socransky and coworkers categorized the oral bacteria of the subgingival plaque into different complexes. Treponema denticola, Porphyromonas gingivalis and Tannerella forsythia are grouped into the red complex that is highly correlated with periodontal disease. Socransky's work closely associates red with orange complex species such as Fusobacterium nucleatum and Prevotella intermedia but not with members of the other complexes. While the relationship between species contained by these complexes is in part supported by their ability to physically attach to each other, the physiological consequences of these interactions and associations are less clear. In this study, we employed T. denticola as a model organism to analyze contact-dependent responses to interactions with species belonging to the same complex (P. gingivalis and T. forsythia), the closely associated orange complex (using F. nucleatum and P. intermedia as representatives) and the unconnected yellow complex (using Streptococcus sanguinis and S. gordonii as representatives). RNA was extracted from T. denticola alone as well as after pairwise co-incubation for 5 hrs with representatives of the different complexes, and the respective gene expression profiles were determined using microarrays. Numerous genes related to motility, metabolism, transport, outer membrane and hypothetical proteins were differentially regulated in T. denticola in the presence of the tested partner species. Further analysis revealed a significant overlap in the affected genes and we identified a general response to the presence of other species, those specific to two of the three complexes as well as individual complexes. Most interestingly, many predicted major antigens (e.g. flagella, Msp, CTLP) were suppressed in responses that included red complex species indicating that the presence of the most closely associated species induces immune-evasive strategies. In summary, the data presented here provide an in-depth understanding of the transcriptional responses triggered by contact-dependent interactions between microorganisms inhabiting the periodontal pocket.

show abstract

Novel transcriptional regulator OxtR1 regulates potential ferrodoxin in response to oxygen stress in Treponema denticola

Numata,

Kikuchi,

Sato

et al. 2024

Anaerobe

View full text Add to dashboard Cite

Transcriptional Profiles of Treponema denticola in Response to Environmental Conditions

Cited by 16 publications

References 44 publications

Dioxygen and nitric oxide scavenging by Treponema denticola flavodiiron protein: a mechanistic paradigm for catalysis

Dioxygen and nitric oxide scavenging by Treponema denticola flavodiiron protein: a mechanistic paradigm for catalysis

Transcriptional Responses of Treponema denticola to Other Oral Bacterial Species

Novel transcriptional regulator OxtR1 regulates potential ferrodoxin in response to oxygen stress in Treponema denticola

Contact Info

Product

Resources

About