Publication: Quorum sensing regulates dpsA and the oxidative stress response in Burkholderia pseudomallei
Issued Date
2006-12-01
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ISSN
13500872
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2-s2.0-33845969858
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Mahidol University
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SCOPUS
Bibliographic Citation
Microbiology. Vol.152, No.12 (2006), 3651-3659
Suggested Citation
Putthapoom Lumijiaktase, Stephen P. Diggle, Suvit Loprasert, Sumalee Tungpradabkul, Mavis Daykin, Miguel Cámara, Paul Williams, Mongkol Kunakorn Quorum sensing regulates dpsA and the oxidative stress response in Burkholderia pseudomallei. Microbiology. Vol.152, No.12 (2006), 3651-3659. doi:10.1099/mic.0.29226-0 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/23275
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Title
Quorum sensing regulates dpsA and the oxidative stress response in Burkholderia pseudomallei
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Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, a fatal human tropical disease. The The non-specific DNA-binding protein DpsA plays a key role in protecting B. pseudomallei from oxidative stress mediated, for example, by organic hydroperoxides. The regulation of dpsA expression is poorly understood but one possibility is that it is regulated in a cell population density-dependent manner via N-acylhomoserine lactone (AHL)-dependent quorum sensing (QS) since a lux-box motif has been located within the dpsA promoter region. Using liquid chromatography and tandem mass spectrometry, it was first established that B. pseudomallei strain PP844 synthesizes AHLs. These were identified as N-octanoylhomoserine lactone (C8-HSL), N-(3-oxooctanoyl)homoserine lactone (3-oxo-C8-HSL), N-(3-hydroxyoctanoyl)-homoserine lactone (3-hydroxy-C8-HSL), N-decanoylhomoserine lactone (C10-HSL), N-(3-hydroxydecanoyl) homoserine lactone (3-hydroxy-C10-HSL) and N-(3-hydroxydodecanoyl)homoserine lactone (3-hydroxy-C12-HSL). Mutation of the genes encoding the Luxl homologue Bpsl or the LuxR homologue BpsR resulted in the loss of C8-HSL and 3-oxo-C8-HSL synthesis, demonstrating that Bpsl was responsible for directing the synthesis of these AHLs only and that bpsl expression and hence C8-HSL and 3-oxo-C8-HSL production depends on BpsR. In bpsl, bpsR and bpslR mutants, dpsA expression was substantially down-regulated. Furthermore, dpsA expression in Escherichia coli required both BpsR and C8-HSL. bpslR-deficient mutants exhibited hypersensitivity to the organic hydroperoxide tert-butyl hydroperoxide by displaying a reduction in cell viability which was restored by provision of exogenous C8-HSL (bpsl mutant only), by complementation with the bpslR genes or by overexpression of dpsA. These data indicate that in B pseudomallei, QS regulates the response to oxidative stress at least in part via the BpsR/ CB-HSL-dependent regulation of DpsA. © 2006 SGM.