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Type III secretion system expression in oxygen-limited Pseudomonas aeruginosa cultures is stimulated by isocitrate lyase activity
Pseudomonas aeruginosa is an opportunistic human pathogen and a common cause of chronic infections in individuals with cystic fibrosis (CF). Oxygen limitation was recently reported to regulate the expression of a major virulence determinant in P. aeruginosa, the type III secretion system (T3SS). Her...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3603453/ https://www.ncbi.nlm.nih.gov/pubmed/23363478 http://dx.doi.org/10.1098/rsob.120131 |
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author | Chung, Jade C. S. Rzhepishevska, Olena Ramstedt, Madeleine Welch, Martin |
author_facet | Chung, Jade C. S. Rzhepishevska, Olena Ramstedt, Madeleine Welch, Martin |
author_sort | Chung, Jade C. S. |
collection | PubMed |
description | Pseudomonas aeruginosa is an opportunistic human pathogen and a common cause of chronic infections in individuals with cystic fibrosis (CF). Oxygen limitation was recently reported to regulate the expression of a major virulence determinant in P. aeruginosa, the type III secretion system (T3SS). Here, we show that expression of the T3SS in oxygen-limited growth conditions is strongly dependent on the glyoxylate shunt enzyme, isocitrate lyase (ICL; encoded by aceA), which was previously shown to be highly expressed in CF isolates. ICL-dependent regulation of the T3SS did not alter the expression level of the master transcriptional regulator, ExsA, but did affect expression of the T3 structural proteins, effectors and regulators (ExsC, ExsD and ExsE). An aceA mutant displayed enhanced biofilm formation during anaerobic growth, which suggested that AceA-dependent modulation of type III secretion might impinge upon the RetS/LadS signalling pathways. Indeed, our data suggest that RetS is able to mediate some of its effects through AceA, as expression of aceA in trans partially restored T3SS expression in a retS mutant. Our findings indicate that AceA is a key player in the metabolic regulation of T3SS expression during oxygen-limited growth of P. aeruginosa. To the best of our knowledge, this is the first demonstration that the T3SS can be regulated by factors that do not affect ExsA expression levels. |
format | Online Article Text |
id | pubmed-3603453 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | The Royal Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-36034532013-04-03 Type III secretion system expression in oxygen-limited Pseudomonas aeruginosa cultures is stimulated by isocitrate lyase activity Chung, Jade C. S. Rzhepishevska, Olena Ramstedt, Madeleine Welch, Martin Open Biol Research Pseudomonas aeruginosa is an opportunistic human pathogen and a common cause of chronic infections in individuals with cystic fibrosis (CF). Oxygen limitation was recently reported to regulate the expression of a major virulence determinant in P. aeruginosa, the type III secretion system (T3SS). Here, we show that expression of the T3SS in oxygen-limited growth conditions is strongly dependent on the glyoxylate shunt enzyme, isocitrate lyase (ICL; encoded by aceA), which was previously shown to be highly expressed in CF isolates. ICL-dependent regulation of the T3SS did not alter the expression level of the master transcriptional regulator, ExsA, but did affect expression of the T3 structural proteins, effectors and regulators (ExsC, ExsD and ExsE). An aceA mutant displayed enhanced biofilm formation during anaerobic growth, which suggested that AceA-dependent modulation of type III secretion might impinge upon the RetS/LadS signalling pathways. Indeed, our data suggest that RetS is able to mediate some of its effects through AceA, as expression of aceA in trans partially restored T3SS expression in a retS mutant. Our findings indicate that AceA is a key player in the metabolic regulation of T3SS expression during oxygen-limited growth of P. aeruginosa. To the best of our knowledge, this is the first demonstration that the T3SS can be regulated by factors that do not affect ExsA expression levels. The Royal Society 2013-01 /pmc/articles/PMC3603453/ /pubmed/23363478 http://dx.doi.org/10.1098/rsob.120131 Text en http://creativecommons.org/licenses/by/3.0/ © 2013 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0/, which permits unrestricted use, provided the original author and source are credited. |
spellingShingle | Research Chung, Jade C. S. Rzhepishevska, Olena Ramstedt, Madeleine Welch, Martin Type III secretion system expression in oxygen-limited Pseudomonas aeruginosa cultures is stimulated by isocitrate lyase activity |
title | Type III secretion system expression in oxygen-limited Pseudomonas aeruginosa cultures is stimulated by isocitrate lyase activity |
title_full | Type III secretion system expression in oxygen-limited Pseudomonas aeruginosa cultures is stimulated by isocitrate lyase activity |
title_fullStr | Type III secretion system expression in oxygen-limited Pseudomonas aeruginosa cultures is stimulated by isocitrate lyase activity |
title_full_unstemmed | Type III secretion system expression in oxygen-limited Pseudomonas aeruginosa cultures is stimulated by isocitrate lyase activity |
title_short | Type III secretion system expression in oxygen-limited Pseudomonas aeruginosa cultures is stimulated by isocitrate lyase activity |
title_sort | type iii secretion system expression in oxygen-limited pseudomonas aeruginosa cultures is stimulated by isocitrate lyase activity |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3603453/ https://www.ncbi.nlm.nih.gov/pubmed/23363478 http://dx.doi.org/10.1098/rsob.120131 |
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