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Autoinducer 2 (AI-2) is required for the growth of Aggregatibacter (Actinobacillus) actinomycetemcomitans in culture under conditions of iron limitation. However, in vivo this organism thrives in a complex multispecies biofilm that forms in the human oral cavity. In this report, we show that adherent growth of A. actinomycetemcomitans on a saliva-coated(More)
Biofilm formation by the periodontal pathogen Aggregatibacter actinomycetemcomitans is dependent upon autoinducer-2 (AI-2)-mediated quorum sensing. However, the components that link the detection of the AI-2 signal to downstream gene expression have not been determined. One potential regulator is the QseBC two-component system, which is part of the(More)
Polypeptides which are immunologically related to the erythrocyte anion transport protein have been identified in a variety of non-erythroid cells. We describe two cDNA clones encoding a human non-erythroid band 3 protein (HKB3) and the mouse erythrocyte band 3 (MEB3) and show that these proteins are structurally similar. Comparison of the predicted amino(More)
Porphyromonas gingivalis is an aggressive periodontal pathogen that persists in the mixed-species plaque biofilm on tooth surfaces. P. gingivalis cells attach to the plaque commensal Streptococcus gordonii and this coadhesion event leads to the development of P. gingivalis biofilms. Binding of these organisms is multimodal, involving both the P. gingivalis(More)
We have previously shown that Actinobacillus actinomycetecomitans produces an immunosuppressive factor (ISF) capable of impairing human lymphocyte function by perturbing cell cycle progression. We now report that ISF is the product of the cdtB gene, one of three genes encoding the family of cytolethal distending toxins (Cdt). The ISF polypeptide exhibits(More)
The antigen I/II family of cell-surface-anchored polypeptides in oral streptococci are structurally complex multi-functional adhesins, with multiple ligand-binding sites. Discrete regions within these polypeptides bind human salivary glycoproteins, other microbial cells, and calcium. Sequences within the N-terminal region bind preferentially fluid-phase(More)
The luxS gene of quorum-sensing Vibrio harveyi is required for type 2 autoinducer production. We identified a Porphyromonas gingivalis open reading frame encoding a predicted peptide of 161 aa that shares 29% identity with the amino acid sequence of the LuxS protein of V. harveyi. Conditioned medium from a late-log-phase P. gingivalis culture induced the(More)
Our previous studies showed that the Aggregatibacter actinomycetemcomitans RbsB protein interacts with cognate and heterologous autoinducer 2 (AI-2) signals and suggested that the rbsDABCK operon encodes a transporter that may internalize AI-2 (D. James et al., Infect. Immun. 74:4021-4029, 2006.). However, A. actinomycetemcomitans also possesses genes(More)
Smokers are more susceptible than non-smokers to persistent infection by Porphyromonas gingivalis, a causative agent of periodontitis. Patients who smoke exhibit increased susceptibility to periodontitis and are more likely to display severe disease and be refractory to treatment. Paradoxically, smokers demonstrate reduced clinical inflammation. We show(More)
Annexin V is a major component of matrix vesicles and has a role in mediating the influx of Ca2+ into these vesicles, thus promoting the initiation of hypertrophic cartilage matrix mineralization. However, the mechanisms and factors regulating annexin V-mediated Ca2+ influx into these vesicles are not well understood. Since the lipid composition of matrix(More)