Comparative and Functional Genomic Analyses of Iron Transport and Regulation in
            <i>Leptospira</i>
            spp

Louvel, Hélène; Bommezzadri, S.; Zidane, Nora; Boursaux-Eude, Caroline; Créno, Sophie; Magnier, A.; Rouy, Zoé; Médigue, Claudine; Girons, Isabelle Saint; Bouchier, Christiane; Picardeau, Mathieu

doi:10.1128/jb.00711-06

Cited by 71 publications

(102 citation statements)

References 68 publications

(82 reference statements)

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“…We also observed high levels of expression of virulence-related proteins belonging to the TolC family and some ABC transporters, which interact in combination to facilitate the efflux of cytoplasmic components [64]. In addition, a TonB-like protein and a TonB-dependent outer membrane receptor were upregulated in strain 56601, indicating the intensified ability to uptake certain iron sources [65] from the environment to help its growth. LigB was reported to bind fibronectin during infection [66,67].…”

Section: Discussionmentioning

confidence: 82%

Comparative proteogenomic analysis of the Leptospira interrogans virulence-attenuated strain IPAV against the pathogenic strain 56601

et al. 2011

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The virulence-attenuated Leptospira interrogans serovar Lai strain IPAV was derived by prolonged laboratory passage from a highly virulent ancestral strain isolated in China. We studied the genetic variations of IPAV that render it avirulent via comparative analysis against the pathogenic L. interrogans serovar Lai strain 56601. The complete genome sequence of the IPAV strain was determined and used to compare with, and then rectify and reannotate the genome sequence of strain 56601. Aside from their highly similar genomic structure and gene order, a total of 33 insertions, 53 deletions and 301 single-nucleotide variations (SNVs) were detected throughout the genome of IPAV directly affecting 101 genes, either in their 5′ upstream region or within their coding region. Among them, the majority of the 44 functional genes are involved in signal transduction, stress response, transmembrane transport and nitrogen metabolism. Comparative proteomic analysis based on quantitative liquid chromatography (LC)-MS/MS data revealed that among 1 627 selected pairs of orthologs, 174 genes in the IPAV strain were upregulated, with enrichment mainly in classes of energy production and lipid metabolism. In contrast, 228 genes in strain 56601 were upregulated, with the majority enriched in the categories of protein translation and DNA replication/repair. The combination of genomic and proteomic approaches illustrated that altered expression or mutations in critical genes, such as those encoding a Ser/Thr kinase, carbon-starvation protein CstA, glutamine synthetase, GTP-binding protein BipA, ribonucleotidediphosphate reductase and phosphate transporter, and alterations in the translational profile of lipoproteins or outer membrane proteins are likely to account for the virulence attenuation in strain IPAV.

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Section: Discussionmentioning

confidence: 82%

Comparative proteogenomic analysis of the Leptospira interrogans virulence-attenuated strain IPAV against the pathogenic strain 56601

et al. 2011

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“…We recently identified transposon mutants of L. biflexa that were not able to use some iron sources for survival (Louvel et al, 2005(Louvel et al, , 2006. Using transposon mutagenesis, we could also screen a library of random mutants in a polystyrene plate assay to identify biofilm-defective mutants.…”

Section: Quantification Of Biofilm Formationmentioning

confidence: 99%

Biofilm formation by saprophytic and pathogenic leptospires

et al. 2008

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“…Leptospira biflexa, a free-living saprophyte, was discovered over 100 years ago (3) and is often used as a model organism for studies of the genus as a whole (2,(4)(5)(6). Although host-associated species, such as Leptospira interrogans, are more intensively studied, they exhibit a low transformation efficiency that approaches the limits of detection.…”

mentioning

confidence: 99%

Multiple Posttranslational Modifications of Leptospira biflexa Proteins as Revealed by Proteomic Analysis

Stewart

Carroll

Olano

et al. 2016

Appl Environ Microbiol

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cThe saprophyte Leptospira biflexa is an excellent model for studying the physiology of the medically important Leptospira genus, the pathogenic members of which are more recalcitrant to genetic manipulation and have significantly slower in vitro growth. However, relatively little is known regarding the proteome of L. biflexa, limiting its utility as a model for some studies. Therefore, we have generated a proteomic map of both soluble and membrane-associated proteins of L. biflexa during exponential growth and in stationary phase. Using these data, we identified abundantly produced proteins in each cellular fraction and quantified the transcript levels from a subset of these genes using quantitative reverse transcription-PCR (RT-PCR). These proteins should prove useful as cellular markers and as controls for gene expression studies. We also observed a significant number of L. biflexa membrane-associated proteins with multiple isoforms, each having unique isoelectric focusing points. L. biflexa cell lysates were examined for several posttranslational modifications suggested by the protein patterns. Methylation and acetylation of lysine residues were predominately observed in the proteins of the membrane-associated fraction, while phosphorylation was detected mainly among soluble proteins. These three posttranslational modification systems appear to be conserved between the free-living species L. biflexa and the pathogenic species Leptospira interrogans, suggesting an important physiological advantage despite the varied life cycles of the different species. Members of the genus Leptospira are spirochetal bacteria that share a conserved spiral morphology and motility. Leptospires can be broadly divided into host-associated species (including pathogens and the closely related intermediate species [1]) and free-living saprophytes, and Picardeau et al. proposed that the host-associated species may have evolved from a free-living progenitor (2). Therefore, comparisons between species with different ecological niches may elucidate the mechanisms that allow host-associated species to infect, persist in, and sometimes cause fatal disease in their hosts.Leptospira biflexa, a free-living saprophyte, was discovered over 100 years ago (3) and is often used as a model organism for studies of the genus as a whole (2, 4-6). Although host-associated species, such as Leptospira interrogans, are more intensively studied, they exhibit a low transformation efficiency that approaches the limits of detection. The higher in vitro growth rate and more efficient genetic tools available to manipulate L. biflexa make this organism better suited for laboratory studies. Techniques such as targeted allelic exchange, transposon mutagenesis, conjugative transfer, the use of fluorescent markers, and the use of an inducible promoter system were first developed in L. biflexa before use in L. interrogans (5, 7-9). However, despite its being a model organism, there are significant gaps in our knowledge of L. biflexa. No large-scale microarray data o...

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Comparative and Functional Genomic Analyses of Iron Transport and Regulation in Leptospira spp

Cited by 71 publications

References 68 publications

Comparative proteogenomic analysis of the Leptospira interrogans virulence-attenuated strain IPAV against the pathogenic strain 56601

Comparative proteogenomic analysis of the Leptospira interrogans virulence-attenuated strain IPAV against the pathogenic strain 56601

Biofilm formation by saprophytic and pathogenic leptospires

Multiple Posttranslational Modifications of Leptospira biflexa Proteins as Revealed by Proteomic Analysis

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