Functional genomics analysis of n-alkyl sulfates toxicity in the yeast Saccharomyces cerevisiae

Abstract

The n-alkyl sulfates (AS) are a class of anionic surfactants that are widely used in industry and in consumer products. In this study, the effects of AS on yeast growth and genome wide transcriptional profiles were analysed by DNA microarray technology. Induced genes were categorized by localization of gene products and by function according to accepted gene ontologies using the MIPS database. A number of genes whose products localized to the cell wall and peroxisome were significantly induced. Genes involved in energy metabolism (i.e., fatty acid β-oxidation pathway) were also significantly induced. To confirm the role of these functions, the sensitivity of selected single gene deletion strains to sodium dodecyl sulfate (SDS) was tested. Deletion strains of cell wall maintenance genes (ΔGAS1, ΔKRE6, and ΔCHS5) were found to be highly sensitive. Interestingly, mutants deleted for genes in the fatty acid β-oxidation pathway were not found to be sensitive. However, regulating genes in the fatty acid β-oxidation pathway were found to respond to SDS exposure in a dose-dependent manner and to be involved in H2O2 production. Here, we report a functional genomics analysis of genome-wide expression data to screen and evaluate AS toxicity in yeast. While the approach begins with a determination of highly-induced genes, its power lies in then determining the most relevant functions targeted by AS, and then assessing loss of key genes by evaluating AS sensitivity in the corresponding deletion mutants.