A Porphyromonas gingivalis haloacid dehalogenase family phosphate interacts with human phosphoproteins and is important for invasion

Department of Oral Biology, University of Florida School of Dentistry, Gainesville, FL 32610-0424, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 08/2006; 103(29):11027-32. DOI: 10.1073/pnas.0509813103
Source: PubMed


Haloacid dehalogenase (HAD) family phosphatases are widespread in prokaryotes and are generally involved in metabolic processes. Porphyromonas gingivalis, an invasive periodontal pathogen, secretes the HAD family phosphoserine phosphatase SerB653 when in contact with gingival epithelial cells. Here we characterize the structure and enzymatic activity of SerB653 and show that a SerB653 allelic replacement mutant of P. gingivalis is deficient in internalization and persistence in gingival epithelial cells. In contrast, mutation of a second HAD family serine phosphatase of P. gingivalis (SerB1170), or of a serine transporter, did not affect invasion. A pull-down assay identified GAPDH and heat-shock protein 90 as potential substrates for SerB653. Furthermore, exogenous phosphatase regulated microtubule dynamics in host cells. These data indicate that P. gingivalis has adapted a formerly metabolic enzyme to facilitate entry into host cells by modulating host cytoskeletal architecture. Our findings define a virulence-related role of a HAD family phosphatase and reveal an invasin of an important periodontal pathogen.

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Available from: Gena D Tribble, Apr 23, 2015
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    • "As part of its strategies for survival into the host, P. gingivalis is able to invade cells and tissues (Yilmaz, 2008), thus avoiding the immune surveillance. Porphyromonas gingivalis can actively invade gingival epithelial cells, where it can maintain viability and replicate (Belton et al., 1999; Tribble et al., 2006). This invasive property is dependent on its major fimbriae, which bind to b1 integrin on the surface of host cells, an event that causes rearrangements of the actin cytoskeleton to allow internalization (Yilmaz et al., 2002, 2003). "
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    ABSTRACT: Porphyromonas gingivalis is a Gram-negative oral anaerobe that is involved in the pathogenesis of periodontitis, an inflammatory disease that destroys the tissues supporting the tooth, eventually leading to tooth loss. Porphyromonas gingivalis has can locally invade periodontal tissues and evade the host defence mechanisms. In doing so, it utilizes a panel of virulence factors that cause deregulation of the innate immune and inflammatory responses. The present review discusses the invasive and evasive strategies of P. gingivalis and the role of its major virulence factors in these, namely lipopolysaccharide, capsule, gingipains and fimbriae. Moreover, the role of P. gingivalis as a 'keystone' biofilm species in orchestrating a host response, is highlighted.
    FEMS Microbiology Letters 04/2012; 333(1):1-9. DOI:10.1111/j.1574-6968.2012.02579.x · 2.12 Impact Factor
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    • "Two autophosphorylated Ser/Thr protein kinases, NleH1 and NleH2, in enterohemorrhagic Escherichia coli, and the OspG protein in Shigella flexneri, inhibit activation of the proinflammatory transcription factor NF-κB.6,7 The serine phosphatase SerB of Porphyromonas gingivalis, which is required for maximal invasion of the organisms into epithelial cells, can impact both the actin and tubulin cytoskeleton of host cells, and also attenuate NF-κB activation.8,9,10 The secretion of serine kinases and/or phosphatases has thus afforded bacterial pathogens the means to interfere with host signal transduction pathways. "
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    ABSTRACT: Protein phosphorylation on tyrosine has emerged as a key device in the control of numerous cellular functions in bacteria. In this article, we review the structure and function of bacterial tyrosine kinases and phosphatases. Phosphorylation is catalyzed by autophosphorylating adenosine triphosphate-dependent enzymes (bacterial tyrosine (BY) kinases) that are characterized by the presence of Walker motifs. The reverse reaction is catalyzed by three classes of enzymes: the eukaryotic-like phosphatases (PTPs) and dual-specific phosphatases; the low molecular weight protein-tyrosine phosphatases (LMW-PTPs); and the polymerase-histidinol phosphatases (PHP). Many BY kinases and tyrosine phosphatases can utilize host cell proteins as substrates, thereby contributing to bacterial pathogenicity. Bacterial tyrosine phosphorylation/dephosphorylation is also involved in biofilm formation and community development. The Porphyromonas gingivalis tyrosine phosphatase Ltp1 is involved in a restraint pathway that regulates heterotypic community development with Streptococcus gordonii. Ltp1 is upregulated by contact with S. gordonii and Ltp1 activity controls adhesin expression and levels of the interspecies signal AI-2.
    International Journal of Oral Science 03/2012; 4(1):1-6. DOI:10.1038/ijos.2012.6 · 2.53 Impact Factor
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    • "Wild type P. gingivalis ATCC 33277, isogenic ΔserB, ΔserB+pserB (Tribble et al., 2006) and serB::FLAG were used in this study. In the complemented strain, the SerB protein is expressed from the pT-COW low copy number plasmid under the control of the serB promoter. "
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    ABSTRACT: Porphyromonas gingivalis, a host-adapted opportunistic pathogen, produces a serine phosphatase, SerB, known to affect virulence, invasion and persistence within the host cell. SerB induces actin filament rearrangement in epithelial cells, but the mechanistic basis of this is not fully understood. Here we investigated the effects of SerB on the actin depolymerizing host protein cofilin. P. gingivalis infection resulted in the dephosphorylation of cofilin in gingival epithelial cells. In contrast, a SerB-deficient mutant of P. gingivalis was unable to cause cofilin dephosphorylation. The involvement of cofilin in P. gingivalis invasion was determined by quantitative image analysis of epithelial cells in which cofilin had been knocked down or knocked in with various cofilin constructs. siRNA-silencing of cofilin led to a significant decrease in numbers of intracellular P. gingivalis marked by an absence of actin colocalization. Transfection with wild-type cofilin or constitutively active cofilin both increased numbers of intracellular bacteria, while constitutively inactive cofilin abrogated invasion. Expression of LIM kinase resulted in reduced P. gingivalis invasion, an effect that was reversed by expression of constitutively active cofilin. These results show that P. gingivalis SerB activity induces dephosphorylation of cofilin, and that active cofilin is required for optimal invasion into gingival epithelial cells.
    Cellular Microbiology 12/2011; 14(4):577-88. DOI:10.1111/j.1462-5822.2011.01743.x · 4.92 Impact Factor
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