Protease IV, a quorum sensing‐dependent protease of Pseudomonas aeruginosa modulates insect innate immunity. Issue 6 (4th November 2014)

• Record Type: Journal Article
• Authors: Park, Su‐Jin; Kim, Soo‐Kyoung; So, Yong‐In; Park, Ha‐Young; Li, Xi‐Hui; Yeom, Doo Hwan; Lee, Mi‐Nan; Lee, Bok‐Luel; Lee, Joon‐Hee
• Is Part Of: Molecular microbiology. Volume 94:Issue 6(2014)
• Page Start: 1298
• Page End: 1314
• Publication Date: 2014-11-04
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12830
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>In <italic>P</italic><italic>seudomonas aeruginosa</italic>, quorum sensing (QS) plays an essential role in pathogenesis and the QS response controls many virulence factors. Using a mealworm, <italic>T</italic><italic>enebrio molitor</italic> as a host model, we found that Protease IV, a QS‐regulated exoprotease of <italic>P</italic><italic>. aeruginosa</italic> functions as a key virulence effector causing the melanization and death of <italic>T</italic><italic>. molitor</italic> larvae. Protease IV was able to degrade zymogens of spätzle processing enzyme (SPE) and SPE‐activating enzyme (SAE) without the activation of the antimicrobial peptide (AMP) production. Since SPE and SAE function to activate spätzle, a ligand of Toll receptor in the innate immune system of <italic>T</italic><italic>. molitor</italic>, we suggest that Protease IV may interfere with the activation of the Toll signaling. Independently of the Toll pathway, the melanization response, another innate immunity was still generated, since Protease IV directly converted <italic>T</italic><italic>enebrio</italic> prophenoloxidase into active phenoloxidase. Protease IV also worked as an important factor in the virulence to brine shrimp and nematode. These results suggest that Protease IV provides <italic>P</italic><italic>. aeruginosa</italic> with a sophisticated way to escape the immune attack of host by interfering with the production of AMPs.</p> </abstract>