Relief from stress and cytotoxicity by mediator and mutations in Saccharomyces cerevisiae

Nucleotide analogues have important uses in chemotherapies against cancer. There are genes such as HAM1 and LOG1 in S. cerevisiae that are involved in tolerance against both the mutagenic purine analogue 6-N-hydroxylaminopurine (HAP) and the cytostatic drug and pyrimidine analogue 5-fluorouracil (5-FU). We have screened a shuttle plasmid library in yeast for genes that confer drug resistance when overexpressed, and tested genetic interactions between found genes. We have furthermore assayed the enzyme kinetics of the 5-FU degrading enzyme LOG1.

The multisubunit complex “mediator” is involved in gene transcription and help link transcription factors to RNA-polymerase II. We are looking into how mutations in mediator subunits effect the response of  S. cerevisiae to different stresses. We do this by phenotypic profiling, and more lately by RNA-seq transcriptomics.