Anaerobe/aerobe environmental flux determines protein expression profiles of Bacteroides fragilis, a redox pathogen

Ferreira, Eliane de Oliveira; Yates, Edwin A.; Jourlin, Michel; Liu, Jian; Domingues, Regina Maria Cavalcanti Pilotto; Goldner, M.

doi:10.1016/j.anaerobe.2010.09.004

Cited by 5 publications

(1 citation statement)

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“…Furthermore, many of the TBDTs that were identified in cells grown in TYG were also produced at a high level in cells grown in the defined media irrespective of the carbon source. While these results indicate that monosaccharides do not strongly influence the expression of genes encoding a core set of TBDTs and other OM proteins, previous studies have suggested that the presence of different complex carbohydrates, iron limitation and the state of anaerobiosis can significantly alter the protein content of the OM [ 38 , 67 , 68 ]. Thus oligosaccharides or other molecules may play a more important role in regulating the synthesis of OM transporters in Bacteroides than monosaccharides.…”

Section: Resultsmentioning

confidence: 57%

Analysis of the Outer Membrane Proteome and Secretome of Bacteroides fragilis Reveals a Multiplicity of Secretion Mechanisms

2015

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Bacteroides fragilis is a widely distributed member of the human gut microbiome and an opportunistic pathogen. Cell surface molecules produced by this organism likely play important roles in colonization, communication with other microbes, and pathogenicity, but the protein composition of the outer membrane (OM) and the mechanisms used to transport polypeptides into the extracellular space are poorly characterized. Here we used LC-MS/MS to analyze the OM proteome and secretome of B. fragilis NCTC 9343 grown under laboratory conditions. Of the 229 OM proteins that we identified, 108 are predicted to be lipoproteins, and 61 are predicted to be TonB-dependent transporters. Based on their proximity to genes encoding TonB-dependent transporters, many of the lipoprotein genes likely encode proteins involved in nutrient or small molecule uptake. Interestingly, protease accessibility and biotinylation experiments indicated that an unusually large fraction of the lipoproteins are cell-surface exposed. We also identified three proteins that are members of a novel family of autotransporters, multiple potential type I protein secretion systems, and proteins that appear to be components of a type VI secretion apparatus. The secretome consisted of lipoproteins and other proteins that might be substrates of the putative type I or type VI secretion systems. Our proteomic studies show that B. fragilis differs considerably from well-studied Gram-negative bacteria such as Escherichia coli in both the spectrum of OM proteins that it produces and the range of secretion strategies that it utilizes.

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Section: Resultsmentioning

confidence: 57%