Skip to main content
bioRxiv
  • Home
  • About
  • Submit
  • ALERTS / RSS
Advanced Search
New Results

Indole Pulse Signalling Regulates the Cytoplasmic pH of E. coli in a Memory-Like Manner

View ORCID ProfileAshraf Zarkan, View ORCID ProfileSantiago Caño Muñiz, View ORCID ProfileJinbo Zhu, View ORCID ProfileKareem Al Nahas, View ORCID ProfileJehangir Cama, View ORCID ProfileUlrich F. Keyser, View ORCID ProfileDavid K. Summers
doi: https://doi.org/10.1101/425538
Ashraf Zarkan
Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Ashraf Zarkan
Santiago Caño Muñiz
Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UKMRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Santiago Caño Muñiz
Jinbo Zhu
The Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Jinbo Zhu
Kareem Al Nahas
The Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Kareem Al Nahas
Jehangir Cama
The Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Jehangir Cama
Ulrich F. Keyser
The Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Ulrich F. Keyser
David K. Summers
Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for David K. Summers
  • For correspondence: dks11@cam.ac.uk
  • Abstract
  • Full Text
  • Info/History
  • Metrics
  • Supplementary material
  • Preview PDF
Loading

SUMMARY

Bacterial cells are critically dependent upon pH regulation. Most proteins function over a limited pH range and the pH gradient across the bacterial cell membrane is central to energy production and transduction1. Here we demonstrate that indole plays a critical role in the regulation of the cytoplasmic pH of E. coli. Indole is an aromatic molecule with diverse signalling roles that in bacteria is produced from tryptophan by the enzyme tryptophanase (TnaA)2. Two modes of indole signalling have been described: persistent and pulse signalling. The latter is illustrated by the brief but intense elevation of intracellular indole during stationary phase entry3,4. We show that E. coli cells growing under conditions where no indole is produced maintain their cytoplasmic pH at 7.8 ± 0.2. In contrast, under conditions permitting indole production, pH is maintained at 7.2 ± 0.2. Experiments where indole was added experimentally to non-producing cultures showed that pH regulation results from pulse, rather than persistent, indole signalling. Furthermore, the application of an artificial pulse of either of two non-biological proton ionophores (DNP or CCCP) caused a similar effect, suggesting that the relevant property of indole in this context is its ability to conduct protons across the cytoplasmic membrane5. Additionally, we show that the effect of the indole pulse that occurs normally during stationary phase entry in rich medium remains as a “memory” to maintain the correct cytoplasmic pH until entry into the next stationary phase. The indole-mediated reduction in cytoplasmic pH may explain why indole provides E. coli with a degree of protection against stresses, including some bactericidal antibiotics.

Copyright 
The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license.
Back to top
PreviousNext
Posted September 24, 2018.
Download PDF

Supplementary Material

Email

Thank you for your interest in spreading the word about bioRxiv.

NOTE: Your email address is requested solely to identify you as the sender of this article.

Enter multiple addresses on separate lines or separate them with commas.
Indole Pulse Signalling Regulates the Cytoplasmic pH of E. coli in a Memory-Like Manner
(Your Name) has forwarded a page to you from bioRxiv
(Your Name) thought you would like to see this page from the bioRxiv website.
Share
Indole Pulse Signalling Regulates the Cytoplasmic pH of E. coli in a Memory-Like Manner
Ashraf Zarkan, Santiago Caño Muñiz, Jinbo Zhu, Kareem Al Nahas, Jehangir Cama, Ulrich F. Keyser, David K. Summers
bioRxiv 425538; doi: https://doi.org/10.1101/425538
Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
Citation Tools
Indole Pulse Signalling Regulates the Cytoplasmic pH of E. coli in a Memory-Like Manner
Ashraf Zarkan, Santiago Caño Muñiz, Jinbo Zhu, Kareem Al Nahas, Jehangir Cama, Ulrich F. Keyser, David K. Summers
bioRxiv 425538; doi: https://doi.org/10.1101/425538

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
  • Tweet Widget
  • Facebook Like
  • Google Plus One

Subject Area

  • Microbiology
Subject Areas
All Articles
  • Animal Behavior and Cognition (1544)
  • Biochemistry (2500)
  • Bioengineering (1757)
  • Bioinformatics (9727)
  • Biophysics (3928)
  • Cancer Biology (2990)
  • Cell Biology (4235)
  • Clinical Trials (135)
  • Developmental Biology (2653)
  • Ecology (4129)
  • Epidemiology (2033)
  • Evolutionary Biology (6931)
  • Genetics (5243)
  • Genomics (6531)
  • Immunology (2207)
  • Microbiology (7012)
  • Molecular Biology (2782)
  • Neuroscience (17410)
  • Paleontology (127)
  • Pathology (432)
  • Pharmacology and Toxicology (712)
  • Physiology (1068)
  • Plant Biology (2515)
  • Scientific Communication and Education (647)
  • Synthetic Biology (835)
  • Systems Biology (2698)
  • Zoology (439)