Sürdürülebilir Kalkınma Amaçları
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- MakaleAçık Erişim2017Analysis of transcriptional profiles of Saccharomyces cerevisiae exposed to bisphenol A
Bereketoglu, Ceyhun; Arga, Kazim Yalcin; Eraslan, Serpil; Mertoglu, Bulent
Bisphenol A (BPA), an endocrine disrupting chemical, is used as a monomer in the production of epoxy resins and polycarbonates, and as a plasticizer in polyvinyl chloride. As such, it is produced in large quantities worldwide and continuously leaches into the environment. To capture the genome reprogramming in eukaryotic cells under BPA exposure, here, we used Saccharomyces cerevisiae as model organism and analyzed the genome-wide transcriptional profiles of S. cerevisiae BY4742 in response to BPA, focusing on two exposure scenarios: (1) exposure to a low inhibition concentration (50 mg/L; resulting in <10 % inhibition in cell number) and (2) a high inhibition concentration (300 mg/L; resulting in >70 % inhibition in cell number). Based on the transcriptional profiling analyses, 81 genes were repressed and 104 genes were induced in response to 50 mg/L BPA. Meanwhile, 378 genes were downregulated and 606 genes were significantly upregulated upon exposure to 300 mg/L BPA. While similar processes were affected by exposure to distinct BPA concentrations, including mitochondrial processes, nucleobase-containing small molecule metabolic processes, transcription from the RNA polymerase II promoter, and mitosis and associated processes, the number and magnitude of differentially expressed genes differ between low and high inhibition concentration treatments. For example, exposure to 300 mg/L BPA resulted in severe changes in the expression levels of several genes involved in oxidative phosphorylation, the tricarboxylic acid cycle, ribosomal activity, replication, and chemical responses. Conversely, only slight changes were observed in the expression of genes involved in these processes in cells exposed to 50 mg/L BPA. These results demonstrate that yeast cells respond to BPA in a concentration-dependent manner at the transcriptional level via different genes and provide insight into the molecular mechanisms underlying the modes of action of BPA.
- MakaleYalnız künye2017Genome reprogramming in Saccharomyces cerevisiae upon nonylphenol exposure
Bereketoglu, Ceyhun; Arga, Kazim Yalcin; Eraslan, Serpil; Mertoglu, Bulent
Bioaccumulative environmental estrogen, nonylphenol (NP; 4-nonylphenol), is widely used as a nonionic surfactant and can affect human health. Since genomes of Saccharomyces cerevisiae and higher eukaryotes share many structural and functional similarities, we investigated subcellular effects of NP on S. cerevisiae BY4742 cells by analyzing genome-wide transcriptional profiles. We examined effects of low (1 mg/l; <15% cell number reduction) and high (5 mg/l; >65% cell number reduction) inhibitory concentration exposures for 120 or 180 min. After 120 and 180 min of 1 mg/l NP exposure, 187 (63 downregulated, 124 upregulated) and 103 genes (56 downregulated, 47 upregulated), respectively, were differentially expressed. Similarly, 678 (168 repressed, 510 induced) and 688 genes (215 repressed, 473 induced) were differentially expressed in cells exposed to 5 mg/l NP for 120 and 180 min, respectively. Only 15 downregulated and 63 upregulated genes were common between low and high NP inhibitory concentration exposure for 120 min, whereas 16 downregulated and 31 upregulated genes were common after the 180-min exposure. Several processes/pathways were prominently affected by either low or high inhibitory concentration exposure, while certain processes were affected by both inhibitory concentrations, including ion transport, response to chemicals, transmembrane transport, cellular amino acids, and carbohydrate metabolism. While minimal expression changes were observed with low inhibitory concentration exposure, 5 mg/l NP treatment induced substantial expression changes in genes involved in oxidative phosphorylation, cell wall biogenesis, ribosomal biogenesis, and RNA processing, and encoding heat shock proteins and ubiquitin-conjugating enzymes. Collectively, these results provide considerable information on effects of NP at the molecular level.