engleski

Combining proteomics and lipid analysis to unravel stress response of Saccharomyces cerevisiae to environmental pollutants

The aim of this study is to further characterize the molecular mechanisms of the stress response to some environmental pollutants’ toxicity using yeast Saccharomyces cerevisiae as a model organism. For this purpose, Imidacloprid – in lowest recommended application dose of Confidor® SL 200 (of 0.025% v/v), and two metals ions Fe3+ and Pb2+ in overloaded concentration (4 mM and 8 mM, respectively) were tested. Cell viability and vitality were analysed, and intracellular oxidation level was measured. Changes at the mitochondrial proteome level and on the mitochondrial lipid content and composition were studied also. Confidor® influence to viability of tested yeast in greater extent than metal-ions. The content of metabolically disturbed cells increased significantly in all treatments (in Confidor® and Fe3+ and Pb2+ - treated cells), measured by yeast-specific fluorescence dye FUN-1. The mitochondrial proteome of all types of treated cells showed the domination of protein down-regulation. Yeast cells treated either with Fe3+ or Pb2+ shared 19 common significantly changed proteins and 3 were downregulated in both (Pda1_α, Ald4 and Sco2). Other downregulated proteins belong to energy and carbohydrate metabolism (Dld1, Cor1, Qcr7, Cox 6, Atp2, Cit1, Qcr2), transport (Tom40), genetic information processing (Rim1) and oxidative stress response (Tsa2). In the mitochondria of Confidor® treated yeast 15 proteins showed a significant expression change. Changed expression in mitochondrial/cytosolic proteins which are part of yeast’s respiratory supercomplexes (Atp2, Rip1, Cor1, Cbr1, Tom 40, OM45, Mic 60), could help in exploring interactors of mitochondrial machineries and place Confidor® in a group of potential interactors, too. In all treated samples, changes in the cell and mitochondrial lipid content and FA composition were determined, also. Downregulation of energy and carbohydrate metabolism related enzymes is a part of lipid rearrangement and accumulation mechanism in order to ensure the cellular homeostasis and protect yeast from the stress.

yeast ; stress response ; proteome ; lipid ; Confidor ; metal toxicity

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