A member of the peptidase M48 superfamily ofPorphyromonas gingivalisis associated with virulencein vitroandin vivo

Abstract

Background In vivo-induced antigen technology was previously used to identify 115 genes induced in Porphyromonas gingivalis W83 during human infection. One of these, PG2197, a conserved hypothetical protein which has homology to a Zn-dependent protease, was examined with respect to a role in disease.DesignThe expression of PG2197 in human periodontitis patients was investigated, but as there is increasing evidence of a direct relationship between P. gingivalis and cardiovascular disease, a mutation was constructed in this gene to also determine its role in adherence, invasion, and persistence within human coronary artery endothelial cells (HCAEC) and neutrophil killing susceptibility.ResultsPlaque samples from 20 periodontitis patients were analyzed by real-time PCR, revealing that PG2197 was expressed in 60.0% of diseased sites compared to 15.8% of healthy sites, even though P. gingivalis was detected in equal numbers from both sites. The expression of this gene was also found to be up-regulated in microarrays at 5 and 30 min of invasion of HCAEC. Interestingly, a PG2197 mutant displayed increased adherence, invasion, and persistence within HCAEC when compared to the wild-type strain.ConclusionThis gene appears to be important for the virulence of P. gingivalis, both in vivo and in vitro.

Identification and characterization of biofilm formation-defective mutants of Xanthomonas citri subsp. citri

“…The XAC1043 gene encodes a 548 amino acid hypothetical protein that belongs to the peptidase_M48 family (Pfam entry PF01435). This type of proteins are Zn-dependent peptidases and were found to be associated with virulence in vivo and in vitro in Porphyromonas gingivalis (Walters et al, 2009 Ballering et al (2009) described that the Enterococcus faecalis GntR protein was necessary during biofilm development. A member of the HutC/FarR subfamily (GntR family) was proposed for the first time to be linked with biofilm formation.…”

Identification ofEnterococcus faecalisantigens specifically expressedin vivo

“…For example, gene expression (mRNA) analysis using real-time PCR for each identified gene could be performed to confirm its in vivo expression. 18 36 Genetic analysis using isogenic mutant (such as siRNA-knockdown or gene destruction) could be performed to confirm the identified genes (proteins) are really related to the disease process, as previously performed. 37 38 …”

Klebsiella pneumoniae yggG Gene Product: A Zinc-Dependent Metalloprotease

“…The soluble and active YggG protein can promote further biochemical studies such as the identification of natural substrate(s) and the search for inhibitors of this enzyme [ 40 ]. It is interesting to see whether yggG knockout of K. pneumoniae strain is also not lethal as in the case of E. coli [ 14 ] and whether it would have any effect on the virulence of K. pneumoniae similar to the previously reported peptidase M48 family of Porphyromonas gingivalis [ 41 ]. In addition, the feasibility of YggG heterologous expression in E. coli is hoped to encourage structural studies of this enzyme.…”