Effects of Mercury onDictyostelium discoideum: Proteomics Reveals the Molecular Mechanisms of Physiological Adaptation and Toxicity

Abstract

Dictyostelium discoideum amoebae were exposed to Hg 2 microM corresponding to a sublethal concentration and Hg 10 microM with the first effects on mortality and replication rate. A total of 900 spots were visualized by 2-DE electrophoresis. Two-hundred fifty single proteins were identified by mass spectrometry. Low Hg concentration (2 microM) treatment induced up-regulation of 13 spots, mainly involved in oxidative stress response/detoxification, oxidoreductase activity, and metabolic processes. High Hg concentration (10 microM) treatment showed a different PES with 12 proteins downregulated and only two up-regulated, mainly involved in cellular metabolic processes, metal ion binding, and transferase activity. The analyses for the carbonylation show no changes after 2 microM Hg(2+) treatment and 13 differentially carbonylated proteins after 10 microM Hg(2+) involved in a broad range of cellular processes. Our findings provide insight into the mechanisms of physiological adaptation and toxicity to a low and an high mercury concentration, respectively, of Dictyostelium amoebae.

Proteome pattern in oysters as a diagnostic tool for metal pollution

“…Environmental proteomics is increasingly employed to elucidate the underlying molecular mechanisms of toxicant responses by aquatic organisms [6][7][8]14,39]. For a better understanding of the mode of action of aquatic pollutants, successful identification of metal-altered proteins is a prerequisite in these animals with unsequenced genomes.…”

Effects of Nickel, Chlorpyrifos and Their Mixture on the Dictyostelium discoideum Proteome

“…The social amoeba Dictyostelium discoideum (strain AX-2) was grown axenically in AX-2 medium as described previously [74]. The cells were grown under laboratory conditions on a Gallenkamp orbital incubator (Sanyo Gallenkamp, Plc.…”

“…After treatments with several doses of nickel, CHP and their mixture, D. discoideum at a culture concentration of 45 × 10 6 cells were washed twice with PAS, centrifuged at 500× g , precipitated and lysed in buffer (0.3% SDS, 200 mM DTT, 30 mM Tris, Protease Inhibitor Cocktail, P2714, Sigma-Aldrich, St Louis, MO, USAS) as described previously [74]. Protein precipitation was performed in 80% ( v / v ) cold acetone in MilliQ water and centrifuged at 5000× g for 10 min.…”

Possible Evolutionary Response to Global Change – Evolutionary Rescue?

“…Until recently, the genomic tools and resources have unfortunately been limited when it came to key ecological species as opposed to models species with plenty of genomic approaches readily available. Recent identification of functional genes and genes linked to quantitative traits are opening the way to the analysis of functional genes and components of genetic control of physiological processes and are therefore expected to contribute to the understanding of local adaptation (Marsano et al, 2010). Population genomics will very soon add important contributions to these issues, delivering substantial amounts of data on regulatory polymorphisms on a genomic scale.…”