Holyoake, L.V., Hunt, S., Sanguinetti, G. et al. (5 more authors) (2016) CydDC-mediated reductant export in Escherichia coli controls the transcriptional wiring of energy metabolism and combats nitrosative stress. Biochemical Journal, 473 (6). pp. 693-701. ISSN 0264-6021
Abstract
The glutathione/cysteine exporter CydDC maintains redox balance in Escherichia coli . A cydD mutant strain was used to probe the influence of CydDC upon reduced thiol export, gene expression, metabolic perturbations, intracellular pH homeostasis, and tolerance to nitric oxide (NO). Loss of CydDC was found to decrease extracytoplasmic thiol levels, whereas overexpression diminished the cytoplasmic thiol content. Transcriptomic analysis revealed a dramatic up-regulation of protein chaperones, protein degradation (via phenylpropionate/phenylacetate catabolism), β-oxidation of fatty acids, and genes involved in nitrate/nitrite reduction. (1)H NMR metabolomics revealed elevated methionine and betaine and diminished acetate and NAD(+) in cydD cells, which was consistent with the transcriptomics-based metabolic model. The growth rate and ΔpH, however, were unaffected, although the cydD strain did exhibit sensitivity to the NO-releasing compound NOC-12. These observations are consistent with the hypothesis that the loss of CydDC-mediated reductant export promotes protein misfolding, adaptations to energy metabolism, and sensitivity to NO. The addition of both glutathione and cysteine to the medium was found to complement the loss of bd -type cytochrome synthesis in a cydD strain (a key component of the pleiotropic cydDC phenotype), providing the first direct evidence that CydDC substrates are able to restore the correct assembly of this respiratory oxidase. These data provide an insight into the metabolic flexibility of E. coli , highlight the importance of bacterial redox homeostasis during nitrosative stress, and report for the first time the ability of periplasmic low molecular weight thiols to restore haem incorporation into a cytochrome complex.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 Authors This is an open access article published by Portland Press Limited and distributed under the Creative Commons Attribution License 3.0 (http://creativecommons.org/licenses/by/3.0/) |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Medicine, Dentistry and Health (Sheffield) > School of Clinical Dentistry (Sheffield) The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) > Department of Molecular Biology and Biotechnology (Sheffield) |
Funding Information: | Funder Grant number BIOTECHNOLOGY AND BIOLOGICAL SCIENCES RESEARCH COUNCIL (BBSRC) BB/C514174/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 16 Mar 2016 16:01 |
Last Modified: | 16 Mar 2016 16:09 |
Published Version: | http://dx.doi.org/10.1042/BJ20150536 |
Status: | Published |
Publisher: | Portland Press |
Refereed: | Yes |
Identification Number: | 10.1042/BJ20150536 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:96541 |