Protein Biomarkers of DNA Damage in Yeast Cells for\nGenotoxicity Screening

Providing\nan unbiased and comprehensive view of the DNA damage\nresponse in cells is critical in genotoxicity screening to identify\nsubstances that cause diverse types of DNA damage. Considering that <i>S. cerevisiae</i> is one of the most well-characterized model\norganisms in molecular and cellular biology, we created a map of the\nDNA damage response network containing the reported signaling pathways\nin yeast cells programmed to constitutively respond to DNA damage.\nA collection of GFP-fused <i>S. cerevisiae</i> yeast strains\ntreated with typical genotoxic agents illuminated the cellular response\nto DNA damage, thereby identifying 15 protein biomarkers encompassing\nall eight documented DNA damage response pathways. Three statistical\nand one deep learning models were proposed to interpret the quantitative\nmolecular toxicity end point, i.e. protein effect level index (PELI),\nby introducing weights of 15 biomarkers in genotoxicity assessment.\nThe method based on standard deviation exhibited the best performance,\nwith an <i>R</i><sup>2</sup> of 0.916 compared to the SOS/umu\ntest and an <i>R</i><sup>2</sup> of 0.989 compared to the\ncomet assay. The GFP-fused yeast-based proteomic assay has minute-level\nresolution of pathway activation data. It provides a concise alternative\nfor fast, efficient, and mechanistic genotoxicity screening for various\nenvironmental and health applications.