Succinate utilisation by Salmonella is inhibited by multiple regulatory systems.

Succinate is a potent immune signalling molecule that is present in the mammalian gut and within macrophages. Both of these infection niches are colonised by the pathogenic bacterium Salmonella enterica serovar Typhimurium during infection. Succinate is a C4-dicarboyxlate that can serve as a source...

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Main Authors: Nicolas Wenner, Xiaojun Zhu, Will P M Rowe, Kristian Händler, Jay C D Hinton
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2024-03-01
Series:PLoS Genetics
Online Access:https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1011142&type=printable
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author Nicolas Wenner
Xiaojun Zhu
Will P M Rowe
Kristian Händler
Jay C D Hinton
author_facet Nicolas Wenner
Xiaojun Zhu
Will P M Rowe
Kristian Händler
Jay C D Hinton
author_sort Nicolas Wenner
collection DOAJ
description Succinate is a potent immune signalling molecule that is present in the mammalian gut and within macrophages. Both of these infection niches are colonised by the pathogenic bacterium Salmonella enterica serovar Typhimurium during infection. Succinate is a C4-dicarboyxlate that can serve as a source of carbon for bacteria. When succinate is provided as the sole carbon source for in vitro cultivation, Salmonella and other enteric bacteria exhibit a slow growth rate and a long lag phase. This growth inhibition phenomenon was known to involve the sigma factor RpoS, but the genetic basis of the repression of bacterial succinate utilisation was poorly understood. Here, we use an experimental evolution approach to isolate fast-growing mutants during growth of S. Typhimurium on succinate containing minimal medium. Our approach reveals novel RpoS-independent systems that inhibit succinate utilisation. The CspC RNA binding protein restricts succinate utilisation, an inhibition that is antagonised by high levels of the small regulatory RNA (sRNA) OxyS. We discovered that the Fe-S cluster regulatory protein IscR inhibits succinate utilisation by repressing the C4-dicarboyxlate transporter DctA. Furthermore, the ribose operon repressor RbsR is required for the complete RpoS-driven repression of succinate utilisation, suggesting a novel mechanism of RpoS regulation. Our discoveries shed light on the redundant regulatory systems that tightly regulate the utilisation of succinate. We speculate that the control of central carbon metabolism by multiple regulatory systems in Salmonella governs the infection niche-specific utilisation of succinate.
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spelling doaj.art-7d3489286e6f4e229084eb204fe19ab02024-03-30T05:32:53ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042024-03-01203e101114210.1371/journal.pgen.1011142Succinate utilisation by Salmonella is inhibited by multiple regulatory systems.Nicolas WennerXiaojun ZhuWill P M RoweKristian HändlerJay C D HintonSuccinate is a potent immune signalling molecule that is present in the mammalian gut and within macrophages. Both of these infection niches are colonised by the pathogenic bacterium Salmonella enterica serovar Typhimurium during infection. Succinate is a C4-dicarboyxlate that can serve as a source of carbon for bacteria. When succinate is provided as the sole carbon source for in vitro cultivation, Salmonella and other enteric bacteria exhibit a slow growth rate and a long lag phase. This growth inhibition phenomenon was known to involve the sigma factor RpoS, but the genetic basis of the repression of bacterial succinate utilisation was poorly understood. Here, we use an experimental evolution approach to isolate fast-growing mutants during growth of S. Typhimurium on succinate containing minimal medium. Our approach reveals novel RpoS-independent systems that inhibit succinate utilisation. The CspC RNA binding protein restricts succinate utilisation, an inhibition that is antagonised by high levels of the small regulatory RNA (sRNA) OxyS. We discovered that the Fe-S cluster regulatory protein IscR inhibits succinate utilisation by repressing the C4-dicarboyxlate transporter DctA. Furthermore, the ribose operon repressor RbsR is required for the complete RpoS-driven repression of succinate utilisation, suggesting a novel mechanism of RpoS regulation. Our discoveries shed light on the redundant regulatory systems that tightly regulate the utilisation of succinate. We speculate that the control of central carbon metabolism by multiple regulatory systems in Salmonella governs the infection niche-specific utilisation of succinate.https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1011142&type=printable
spellingShingle Nicolas Wenner
Xiaojun Zhu
Will P M Rowe
Kristian Händler
Jay C D Hinton
Succinate utilisation by Salmonella is inhibited by multiple regulatory systems.
PLoS Genetics
title Succinate utilisation by Salmonella is inhibited by multiple regulatory systems.
title_full Succinate utilisation by Salmonella is inhibited by multiple regulatory systems.
title_fullStr Succinate utilisation by Salmonella is inhibited by multiple regulatory systems.
title_full_unstemmed Succinate utilisation by Salmonella is inhibited by multiple regulatory systems.
title_short Succinate utilisation by Salmonella is inhibited by multiple regulatory systems.
title_sort succinate utilisation by salmonella is inhibited by multiple regulatory systems
url https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1011142&type=printable
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AT willpmrowe succinateutilisationbysalmonellaisinhibitedbymultipleregulatorysystems
AT kristianhandler succinateutilisationbysalmonellaisinhibitedbymultipleregulatorysystems
AT jaycdhinton succinateutilisationbysalmonellaisinhibitedbymultipleregulatorysystems