DsbA plays a critical and multifaceted role in the production of secreted virulence factors by the phytopathogen Erwinia carotovora subsp atroseptica

Sarah J. Coulthurst, Kathryn S. Lilley, Peter E. Hedley, Hui Liu, Ian K. Toth, George P. C. Salmond (Lead / Corresponding author)

    Research output: Contribution to journalArticle

    34 Citations (Scopus)

    Abstract

    Erwinia carotovora subsp. atroseptica is an enterobacterial phytopathogen causing economically significant soft rot disease. Pathogenesis is mediated by multiple secreted virulence factors, many of which are secreted by the type II (Out) secretion system. DsbA catalyzes the introduction of disulfide bonds into periplasmic and secreted proteins. In this study, the extracellular proteome (secretome) of wild type E. carotovora subsp. atroseptica SCRI1043, and dsbA and out mutants, was analyzed by spectral counting mass spectrometry. This revealed that dsbA inactivation had a huge impact on the secretome and identified diverse DsbA- and Out-dependent secreted proteins, representing known, predicted, and novel candidate virulence factors. Further characterization of the dsbA mutant showed that secreted enzyme activities, motility, production of the quorum-sensing signal, and virulence were absent or substantially reduced. The impact of DsbA on secreted virulence factor production was mediated at multiple levels, including impacting on the Out secretion system and the virulence gene regulatory network. Transcriptome analyses revealed that the abundance of a broad, but defined, set of transcripts, including many virulence factors, was altered in the dsbA mutant, identifying a new virulence regulon responsive to extracytoplasmic conditions. In conclusion, DsbA plays a crucial, multifaceted role in the pathogenesis of E. carotovora subsp. atroseptica.

    Original languageEnglish
    Pages (from-to)23739-23753
    Number of pages15
    JournalJournal of Biological Chemistry
    Volume283
    Issue number35
    DOIs
    Publication statusPublished - 29 Aug 2008

    Keywords

    • DISULFIDE BOND FORMATION
    • GRAM-NEGATIVE BACTERIA
    • ESCHERICHIA-COLI
    • PSEUDOMONAS-AERUGINOSA
    • PULLULANASE SECRETION
    • ENTERIC PHYTOPATHOGEN
    • PROTEIN SECRETION
    • ISOMERASE DSBC
    • CHRYSANTHEMI
    • PATHOGENESIS

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