Catabolite repression in Pseudomonas aeruginosa PAO1 regulates the uptake of C4 -dicarboxylates depending on succinate concentration.

Details

Serval ID
serval:BIB_0D718E830B30
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Catabolite repression in Pseudomonas aeruginosa PAO1 regulates the uptake of C4 -dicarboxylates depending on succinate concentration.
Journal
Environmental Microbiology
Author(s)
Valentini M., Lapouge K.
ISSN
1462-2920 (Electronic)
ISSN-L
1462-2912
Publication state
Published
Issued date
2013
Volume
15
Number
6
Pages
1707-1716
Language
english
Abstract
In Pseudomonas aeruginosa carbon catabolite repression (CCR) is exerted by the CbrA/B-CrcZ-Crc global regulatory system. Crc is a translational repressor that, in the presence of preferred carbon sources, such as C4 -dicarboxylates, impairs the utilization of less preferred substrates. When non-preferred substrates are present, the CrcZ sRNA levels increase leading to Crc capture, thereby allowing growth of the bacterium at the expense of the non-preferred substrates. The C4 -dicarboxylate transport (Dct) system in P. aeruginosa is composed of two main transporters: DctA, more efficient at mM succinate concentrations, and DctPQM, more important at μM. In this study, we demonstrate that the Dct transporters are differentially regulated by Crc, depending on the concentration of succinate. At high concentrations, Crc positively regulates the expression of the dctA transporter gene and negatively regulates dctPQM post-transcriptionally. The activation of dctA is explained by a Crc-mediated repression of dctR, encoding a transcriptional repressor of dctA. At low succinate concentrations, Crc regulation is impaired. In this condition, CrcZ levels are higher and therefore more Crc proteins are sequestered, decreasing the amount of Crc available to perform CCR on dctR and dctPQM. As a result, expression of dctA is reduced and that of dctPQM is increased.
Pubmed
Web of science
Create date
17/01/2013 17:16
Last modification date
20/08/2019 13:34
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