Issue 56, 2017, Issue in Progress

Intracellular free Ca2+ signals antibiotic exposure in cyanobacteria

Abstract

Intracellular free Ca2+, [Ca2+]i, is a key element of the cellular response to many abiotic and biotic stresses. Cyanobacteria are ancient organisms which have evolved signal transduction systems in response to an ever changing environment. Cyanobacteria have been found to respond to specific and quick Ca2+ signatures (unique combinations of changes in [Ca2+]i) when exposed to environmental stress. Antibiotics are bioactive molecules which are being considered as pseudopersistent contaminants as they are being continuously released to the environment; although non-target organisms, cyanobacteria as prokaryotes are sensitive to antibiotics. In order to check whether [Ca2+]i could be involved in sensing antibiotic exposure, we have recorded the Ca2+ signatures induced by antibiotics belonging to different classes at two effective toxicity concentrations, the EC10 and the EC50. For that, we have used a recombinant bioluminescent strain of the cyanobacterium Anabaena sp. PCC7120 that constitutively expresses the calcium-binding indicator protein, apoaequorin. We found that Ca2+ signatures upon exposure to antibiotics were induced quickly (2–3 seconds) and that they differed between antibiotics and antibiotic concentration. As different classes of antibiotics have been detected simultaneously in the aquatic environment, we also recorded and analyzed the Ca2+ signatures induced by binary mixtures and a multiantibiotic mixture; we found that these Ca2+ signatures could determine the nature of the interaction between antibiotics in the mixture, whether synergistic or antagonistic, well before toxicity was evident. To our knowledge, this study is the first report of intracellular free Ca2+ as an early biomarker of antibiotic exposure in the environment.

Graphical abstract: Intracellular free Ca2+ signals antibiotic exposure in cyanobacteria

Supplementary files

Article information

Article type
Paper
Submitted
13 Mar 2017
Accepted
08 Jul 2017
First published
14 Jul 2017
This article is Open Access
Creative Commons BY license

RSC Adv., 2017,7, 35385-35393

Intracellular free Ca2+ signals antibiotic exposure in cyanobacteria

M. González-Pleiter, F. Leganés and F. Fernández-Piñas, RSC Adv., 2017, 7, 35385 DOI: 10.1039/C7RA03001K

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements