PPE and PE-PGRS proteins of Mycobacterium marinum are transported via the type VII secretion system ESX-5

Abdallah M. Abdallah, Theo Verboom, Eveline M. Weerdenburg, Nicolaas C. Gey Van Pittius, Phetole W. Mahasha, Connie Jiménez, Marcela Parra, Nathalie Cadieux, Michael J. Brennan, Ben J. Appelmelk, Wilbert Bitter*

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    200 Scopus citations


    ESX-5 is one of the five type VII secretion systems found in mycobacteria. These secretion systems are also known as ESAT-6-like secretion systems. Here, we have determined the secretome of ESX-5 by a proteomic approach in two different strains of Mycobacterium marinum. Comparison of the secretion profile of wild-type strains and their ESX-5 mutants showed that a number of PE-PGRS and PPE-MPTR proteins are dependent on ESX-5 for transport. The PE and PPE protein families are unique to mycobacteria, are highly expanded in several pathogenic species, such as Mycobacterium tuberculosis and M. marinum, and certain family members are cell surface antigens associated with virulence. Using a monoclonal antibody directed against the PGRS domain we showed that nearly all PE-PGRS proteins that are recognized by this antibody are missing in the supernatant of ESX-5 mutants. In addition to PE-PGRS and PPE proteins, the ESX-5 secretion system is responsible for the secretion of a ESAT-6-like proteins. Together, these data show that ESX-5 is probably a major secretion pathway for mycobacteria and that this system is responsible for the secretion of recently evolved PE-PGRS and PPE proteins.

    Original languageEnglish (US)
    Pages (from-to)329-340
    Number of pages12
    JournalMolecular Microbiology
    Issue number3
    StatePublished - Aug 2009

    ASJC Scopus subject areas

    • Microbiology
    • Molecular Biology

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