Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 114, Issue 26, Pages E5236-E5245Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1700264114
Keywords
biofilm; redox regulation; phenazines; Pseudomonas aeruginosa; c-di-GMP
Categories
Funding
- Gilliam Fellowship from the Howard Hughes Medical Institute
- Diversity Supplement to NIH [R01AI103369]
- NIH parent Grant
- NIH [R01AI110740]
Ask authors/readers for more resources
Diverse organisms secrete redox-active antibiotics, which can be used as extracellular electron shuttles by resistant microbes. Shuttle-mediated metabolism can support survival when substrates are available not locally but rather at a distance. Such conditions arise in multicellular communities, where the formation of chemical gradients leads to resource limitation for cells at depth. In the pathogenic bacterium Pseudomonas aeruginosa PA14, antibiotics called phenazines act as oxidants to balance the intracellular redox state of cells in anoxic biofilm subzones. PA14 colony biofilms show a profound morphogenic response to phenazines resulting from electron acceptor-dependent inhibition of ECM production. This effect is reminiscent of the developmental responses of some eukaryotic systems to redox control, but for bacterial systems its mechanistic basis has not been well defined. Here, we identify the regulatory protein RmcA and show that it links redox conditions to PA14 colony morphogenesis by modulating levels of bis-(3',5')-cyclic-dimeric-guanosine (c-di-GMP), a second messenger that stimulates matrix production, in response to phenazine availability. RmcA contains four Per-Arnt-Sim (PAS) domains and domains with the potential to catalyze the synthesis and degradation of c-di-GMP. Our results suggest that phenazine production modulates RmcA activity such that the protein degrades c-di-GMP and thereby inhibits matrix production during oxidizing conditions. RmcA thus forms a mechanistic link between cellular redox sensing and community morphogenesis analogous to the functions performed by PAS-domain-containing regulatory proteins found in complex eukaryotes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available