Dataset Information

Calcium homeostasis in Pseudomonas aeruginosa requires multiple transporters and modulates swarming motility.

ABSTRACT: Pseudomonas aeruginosa is an opportunistic human pathogen causing severe acute and chronic infections. Earlier we have shown that calcium (Ca(2+)) induces P. aeruginosa biofilm formation and production of virulence factors. To enable further studies of the regulatory role of Ca(2+), we characterized Ca(2+) homeostasis in P. aeruginosa PAO1 cells. By using Ca(2+)-binding photoprotein aequorin, we determined that the concentration of free intracellular Ca(2+) ([Ca(2+)]in) is 0.14±0.05?M. In response to external Ca(2+), the [Ca(2+)]in quickly increased at least 13-fold followed by a multi-phase decline by up to 73%. Growth at elevated Ca(2+) modulated this response. Treatment with inhibitors known to affect Ca(2+) channels, monovalent cations gradient, or P-type and F-type ATPases impaired [Ca(2+)]in response, suggesting the importance of the corresponding mechanisms in Ca(2+) homeostasis. To identify Ca(2+) transporters maintaining this homeostasis, bioinformatic and LC-MS/MS-based membrane proteomic analyses were used. [Ca(2+)]in homeostasis was monitored for seven Ca(2+)-affected and eleven bioinformatically predicted transporters by using transposon insertion mutants. Disruption of P-type ATPases PA2435, PA3920, and ion exchanger PA2092 significantly impaired Ca(2+) homeostasis. The lack of PA3920 and vanadate treatment abolished Ca(2+)-induced swarming, suggesting the role of the P-type ATPase in regulating P. aeruginosa response to Ca(2+).

SUBMITTER: Guragain M

PROVIDER: S-EPMC4410972 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Calcium homeostasis in Pseudomonas aeruginosa requires multiple transporters and modulates swarming motility.

Guragain Manita M Lenaburg Dirk L DL Moore Frank S FS Reutlinger Ian I Patrauchan Marianna A MA

Cell calcium 20130908 5

Pseudomonas aeruginosa is an opportunistic human pathogen causing severe acute and chronic infections. Earlier we have shown that calcium (Ca(2+)) induces P. aeruginosa biofilm formation and production of virulence factors. To enable further studies of the regulatory role of Ca(2+), we characterized Ca(2+) homeostasis in P. aeruginosa PAO1 cells. By using Ca(2+)-binding photoprotein aequorin, we determined that the concentration of free intracellular Ca(2+) ([Ca(2+)]in) is 0.14±0.05μM. In respon ...[more]

PMID: 24074964

Similar Datasets

Project description:BackgroundThe bacterium Pseudomonas aeruginosa is capable of three types of motilities: swimming, twitching and swarming. The latter is characterized by a fast and coordinated group movement over a semi-solid surface resulting from intercellular interactions and morphological differentiation. A striking feature of swarming motility is the complex fractal-like patterns displayed by migrating bacteria while they move away from their inoculation point. This type of group behaviour is still poorly understood and its characterization provides important information on bacterial structured communities such as biofilms. Using GeneChip® Affymetrix microarrays, we obtained the transcriptomic profiles of both bacterial populations located at the tip of migrating tendrils and swarm center of swarming colonies and compared these profiles to that of a bacterial control population grown on the same media but solidified to not allow swarming motility.ResultsMicroarray raw data were corrected for background noise with the RMA algorithm and quantile normalized. Differentially expressed genes between the three conditions were selected using a threshold of 1.5 log2-fold, which gave a total of 378 selected genes (6.3% of the predicted open reading frames of strain PA14). Major shifts in gene expression patterns are observed in each growth conditions, highlighting the presence of distinct bacterial subpopulations within a swarming colony (tendril tips vs. swarm center). Unexpectedly, microarrays expression data reveal that a minority of genes are up-regulated in tendril tip populations. Among them, we found energy metabolism, ribosomal protein and transport of small molecules related genes. On the other hand, many well-known virulence factors genes were globally repressed in tendril tip cells. Swarm center cells are distinct and appear to be under oxidative and copper stress responses.ConclusionsResults reported in this study show that, as opposed to swarm center cells, tendril tip populations of a swarming colony displays general down-regulation of genes associated with virulence and up-regulation of genes involved in energy metabolism. These results allow us to propose a model where tendril tip cells function as «scouts» whose main purpose is to rapidly spread on uncolonized surfaces while swarm center population are in a state allowing a permanent settlement of the colonized area (biofilm-like).

Dataset Information

Calcium homeostasis in Pseudomonas aeruginosa requires multiple transporters and modulates swarming motility.

Publications

Calcium homeostasis in Pseudomonas aeruginosa requires multiple transporters and modulates swarming motility.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets