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Protein secretion in Pseudomonas aeruginosa
J Tommassen1, A Filloux, M Bally
1Department of Molecular Cell Biology, University of Utrecht, Netherlands.
FEMS Microbiology Reviews
|September 1, 1992
Summary
Pseudomonas aeruginosa utilizes two main protein secretion pathways. One pathway involves the Xcp system, crucial for processing secretion apparatus components and type IV pili, while the alkaline protease secretion follows a distinct route.
Area of Science:
- Microbiology
- Molecular Biology
- Bacterial Pathogenesis
Background:
- Gram-negative bacteria, like Pseudomonas aeruginosa, possess complex protein secretion systems.
- Understanding these systems is vital for deciphering bacterial communication and pathogenesis.
Purpose of the Study:
- To elucidate the distinct protein secretion pathways in Pseudomonas aeruginosa.
- To investigate the role of the Xcp system and its components in protein translocation.
- To explore the relationship between the secretion apparatus and type IV pili biogenesis.
Main Methods:
- Analysis of Pseudomonas aeruginosa exoprotein secretion mechanisms.
- Identification and characterization of key proteins involved in secretion (e.g., XcpA, XcpR, XcpS).
- Investigation of the alkaline protease secretion pathway, independent of the Xcp system.
Main Results:
- Two major secretion pathways identified in P. aeruginosa.
- The Xcp system, involving at least 12 genes, facilitates a two-step secretion process across inner and outer membranes.
- XcpA acts as a peptidase, processing precursors for secretion apparatus assembly and type IV pili.
- Alkaline protease secretion (via aprA gene) bypasses the Xcp system, suggesting a one-step mechanism at adhesion zones.
Conclusions:
- The Xcp system is essential for the assembly of the secretion apparatus and type IV pili biogenesis.
- Distinct secretion mechanisms exist within P. aeruginosa, highlighting pathway diversity.
- These secretion pathways are conserved among Gram-negative bacteria.