Heterogeneity in surface sensing suggests a division of labor in Pseudomonas aeruginosa populations
Abstract
The second messenger signaling molecule cyclic diguanylate monophosphate (c-di-GMP) drives the transition from planktonic to biofilm growth in many bacterial species. Pseudomonas aeruginosa has two surface sensing systems that produce c-di-GMP in response to surface adherence. The current thinking in the field is that once cells attach to a surface, they uniformly respond with elevated c-di-GMP. Here, we describe how the Wsp system generates heterogeneity in surface sensing, resulting in two physiologically distinct subpopulations of cells. One subpopulation has elevated c-di-GMP and produces biofilm matrix, serving as the founders of initial microcolonies. The other subpopulation has low c-di-GMP and engages in surface motility, allowing for exploration of the surface. We also show that this heterogeneity strongly correlates to surface behavior for descendent cells. Together, our results suggest that after surface attachment, P. aeruginosa engages in a division of labor that persists across generations, accelerating early biofilm formation and surface exploration.
Data availability
Source data files and/or MATLAB code have been provided for Figures 3, 4, and 5.
Article and author information
Author details
Funding
National Institutes of Health (T32GM007270)
- Catherine R Armbruster
National Natural Science Foundation of China (21774117)
- Fan Jin
National Natural Science Foundation of China (21522406)
- Fan Jin
Fundamental Research Funds for the Central Universities (WK3450000003)
- Fan Jin
Charlie Moore Endowed Fellowship
- Catherine R Armbruster
Army Research Office (W911NF1810254)
- Matthew R Parsek
National Institutes of Health (K22AI121097)
- Boo Shan Tseng
National Institute of General Medical Sciences (GM56665)
- Caroline S Harwood
National Natural Science Foundation of China (21474098)
- Fan Jin
Fundamental Research Funds for the Central Universities (WK2340000066)
- Fan Jin
National Institutes of Health (K24HL141669)
- Lucas R Hoffman
National Institutes of Health (5R01AI077628)
- Matthew R Parsek
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Alexandre Persat, EPFL, Switzerland
Version history
- Received: January 11, 2019
- Accepted: June 8, 2019
- Accepted Manuscript published: June 10, 2019 (version 1)
- Version of Record published: July 9, 2019 (version 2)
- Version of Record updated: May 26, 2020 (version 3)
Copyright
© 2019, Armbruster et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 5,395
- views
-
- 866
- downloads
-
- 95
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Microbiology and Infectious Disease
- Structural Biology and Molecular Biophysics
African trypanosomes replicate within infected mammals where they are exposed to the complement system. This system centres around complement C3, which is present in a soluble form in serum but becomes covalently deposited onto the surfaces of pathogens after proteolytic cleavage to C3b. Membrane-associated C3b triggers different complement-mediated effectors which promote pathogen clearance. To counter complement-mediated clearance, African trypanosomes have a cell surface receptor, ISG65, which binds to C3b and which decreases the rate of trypanosome clearance in an infection model. However, the mechanism by which ISG65 reduces C3b function has not been determined. We reveal through cryogenic electron microscopy that ISG65 has two distinct binding sites for C3b, only one of which is available in C3 and C3d. We show that ISG65 does not block the formation of C3b or the function of the C3 convertase which catalyses the surface deposition of C3b. However, we show that ISG65 forms a specific conjugate with C3b, perhaps acting as a decoy. ISG65 also occludes the binding sites for complement receptors 2 and 3, which may disrupt recruitment of immune cells, including B cells, phagocytes, and granulocytes. This suggests that ISG65 protects trypanosomes by combining multiple approaches to dampen the complement cascade.