Open AccessThe global regulator Crc plays a multifaceted role in modulation of type III secretion system in P seudomonas aeruginosa
Author(s) -
Dong YiHu,
Zhang XiFen,
Zhang LianHui
Publication year - 2013
Publication title -
microbiologyopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.881
H-Index - 36
ISSN - 2045-8827
DOI - 10.1002/mbo3.54
Subject(s) - effector , mutant , regulator , secretion , biology , downregulation and upregulation , transcriptome , virulence , gene , microbiology and biotechnology , type three secretion system , pathogen , signal transduction , response regulator , gene expression , genetics , biochemistry
The opportunistic pathogen P seudomonas aeruginosa utilizes type III secretion system ( T 3 SS ) to translocate effector proteins into eukaryotic host cells that subvert normal host cell functions to the benefit of the pathogen, and results in serious infections. T 3 SS in P . aeruginosa is controlled by a complex system of regulatory mechanisms and signaling pathways. In this study, we described that Crc , an RNA ‐binding protein, exerts a positive impact on T 3 SS in P . aeruginosa , as evidenced by promoter activity assays of several key T 3 SS genes, transcriptomics, RT ‐ PCR , and immunoblotting in crc mutant. We further demonstrated that the regulatory function of Crc on the T 3 SS was mediated through the T 3 SS master regulator ExsA and linked to the Cbr / Crc signaling system. Expression profiling of the crc mutant revealed a downregulation of flagship T 3 SS genes as well as 16 other genes known to regulate T 3 SS gene expression in P . aeruginosa . On the basis of these data, we proposed that Crc may exert multifaceted control on the T 3 SS through various pathways, which may serve to fine‐tune this virulence mechanism in response to environmental changes and nutrient sources.