Project description:Transcriptional profiling of the wild-type and its htrA mutant. Identification of genes that are affected by the htrA mutation in P. gingivalis Keywords: Genetic modification
Project description:Porphyromonas gingivalis is a major pathogen associated with the microbial biofilm-mediated disease chronic periodontitis. P. gingivalis has an obligate requirement for iron and protoporphyrin IX which it satisfies by transporting heme and iron liberated from the human host. The level of cellular iron in P. gingivalis affects the expression of a distinct iron-associated regulon of 64 genes and low iron invokes an iron sparing response. Iron homeostasis is usually mediated in Gram-negative bacteria at the transcriptional level by the Ferric Uptake Regulator (Fur). There is a single predicted P. gingivalis Fur superfamily orthologue named Har (heme associated regulator) that lacks the conserved metal binding residues found in other Fur orthologues. We show that Har binds both heme and ferrous iron resulting in a conformational change in the protein. Har was unable to complement the Escherichia coli H1780 fur mutant and there was no change in cellular metal content in a P. gingivalis Har mutant compared with the wild-type. The Har regulon of 44 genes is not predicted to play a role in iron homeostasis. Together these data indicated that Har does not regulate iron homeostasis in P. gingivalis. However, Har was required for heme-responsive biofilm development and its regulon overlapped P. gingivalis regulons previously identified after growth in heme limitation or as a homotypic biofilm. P. gingivalis is unique as an iron-dependent Gram-negative bacterium with a single heme-binding Fur superfamily orthologue, Har, that does not regulate iron homeostasis.
Project description:Transcriptional profiling of the wild-type and its htrA mutant. Identification of genes that are affected by the htrA mutation in P. gingivalis Keywords: Genetic modification Two-condition experiment, W83 vs. htrA mutant late-log growth phase. Biological replicates: 4 control, 4 mutant, independently grown. One replicate per array.
Project description:Porphyromonas gingivalis is a major pathogen associated with the microbial biofilm-mediated disease chronic periodontitis. P. gingivalis has an obligate requirement for iron and protoporphyrin IX which it satisfies by transporting heme and iron liberated from the human host. The level of cellular iron in P. gingivalis affects the expression of a distinct iron-associated regulon of 64 genes and low iron invokes an iron sparing response. Iron homeostasis is usually mediated in Gram-negative bacteria at the transcriptional level by the Ferric Uptake Regulator (Fur). There is a single predicted P. gingivalis Fur superfamily orthologue named Har (heme associated regulator) that lacks the conserved metal binding residues found in other Fur orthologues. We show that Har binds both heme and ferrous iron resulting in a conformational change in the protein. Har was unable to complement the Escherichia coli H1780 fur mutant and there was no change in cellular metal content in a P. gingivalis Har mutant compared with the wild-type. The Har regulon of 44 genes is not predicted to play a role in iron homeostasis. Together these data indicated that Har does not regulate iron homeostasis in P. gingivalis. However, Har was required for heme-responsive biofilm development and its regulon overlapped P. gingivalis regulons previously identified after growth in heme limitation or as a homotypic biofilm. P. gingivalis is unique as an iron-dependent Gram-negative bacterium with a single heme-binding Fur superfamily orthologue, Har, that does not regulate iron homeostasis. Paired samples were compared on the same microarray using a two-colour system. A total of 6 paired microarray hybridizations were performed representing 6 biological replicates, where a balanced dye design was used, with the overall analysis including three microarrays where P. gingivalis 33277 samples were labeled with Cy3 and the paired ECR455 samples were labeled with Cy5 and three other microarrays where samples were labeled with the opposite combination of fluorophores.
Project description:Wild type Porphyromonas gingivalis strain ATCC33277 (V3176) and PG1626 - deficient mutant (V3177) were grown in iron replete conditions was used to compare to Porphyromonas gingivalis strains grown in iron chelated conditions.
Project description:The P. gingivalis 33277 transposon mutant J5-c5, isolated in this study, was demonstrated to exhibit a lipid A deacylase phenotype. The mutant is unable to deacylate lipid A, which confers to it, in stark contrast to wild-type, an inability to evade the powerful TLR4 innate immune response. The mutant was shown to contain five transposons. In order to determine the affected gene responsible for this phenotype, we took the approach of comparing gene expression between wild-type and J5-c5 transposon mutant. RNA was extracted from three separate biological samples of each strain and RNAseq performed using Illumina’s HiSeq sequencing facility at the University of Washington Center for Precision Diagnostics. RNAseq data was analyzed closely following guidance outlined in Law et al (doi:10.12688/f1000research.9005.2).
Project description:RNA-Seq of wild-type Porphyromonas gingivalis compared to ΔPGN_1524 mutant Illumina based RNA-Seq was used to probe transcriptome differences between wild-type Porphyromonas gingivalis and ΔPGN_1524 mutant
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.