Extracellular vesicles as an alternative copper-secretion mechanism in bacteria

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Lima, S (Author) Other; Matinha-Cardoso, J (Author) Other; Giner-Lamia, J (Author) Other; Couto, N (Author) Other; Pacheco, CC (Author) Other; Florencio, FJ (Author) Other; Wright, PC (Author) Other; Paula Tamagnini (Author) FCUP; Oliveira, P (Author) FCUP

Journal

Title: Journal of Hazardous Materials

Vol. 431

ISSN: 0304-3894

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 22 Citations

Other information

Authenticus ID: P-00W-7PY

DOI: 10.1016/j.jhazmat.2022.128594

Abstract (EN): Metal homeostasis is fundamental for optimal performance of cell metabolic pathways. Over the course of evolution, several systems emerged to warrant an intracellular metal equilibrium. When exposed to growthchallenging copper concentrations, Gram-negative bacteria quickly activate copper-detoxification mechanisms, dependent on transmembrane-protein complexes and metallochaperones that mediate metal efflux. Here, we show that vesiculation is also a common bacterial response mechanism to high copper concentrations, and that extracellular vesicles (EVs) play a role in transporting copper. We present evidence that bacteria from different ecological niches release copious amounts of EVs when exposed to copper. Along with the activation of the classical detoxification systems, we demonstrate that copper-stressed cells of the cyanobacterium Synechocystis sp. PCC6803 release EVs loaded with the copper-binding metallochaperone CopM. Under standard growth conditions, CopM-loaded EVs could also be isolated from a Synechocystis strain lacking a functional TolC-protein, which we characterize here as exhibiting a copper-sensitive phenotype. Analyses of Synechocystis tolC-mutant's EVs isolated from cells cultivated under standard conditions indicated the presence of copper therein, in significantly higher levels as compared to those from the wild-type. Altogether, these results suggest that release of EVs in bacteria represent a novel copper-secretion mechanism, shedding light into alternative mechanisms of bacterial metal resistance.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13