Using a D2-Dopamine Receptor Chimera to Assay Genes Essential to Psychoactive Drug Response in Baker’s Yeast

Zelun Zhang, Alexander Tigert, Marinella Gebbia, Corey Nislow


A powerful approach to understanding gene-drug interactions is to express human cell membrane receptors in baker’s yeast (S. cerevisiae) because of the experimental tractability of yeast and homology between human and yeast proteins. S. cerevisiae individuals were engineered to express the ligand binding domain of the human D2-dopamine receptor as a fusion on the amino terminus of the yeast mating receptor in order to quantify the efficacy of various psychoactivedrugs. In addition, an examination into the side effects of drug treatments was conducted through a genome-wide screen. Experimental and control strains were mated with the Yeast Knockout Collection using Synthetic Genetic Array technology, and pools of deletion mutants expressing the construct were then treated with 55 serotonin uptake inhibitor and α2-adrenoceptor drugs to quantitatively measure receptor response via growth assays. Nine drug treatments were then selected to determine their effects on pools of individual mutant strains – PCR barcodes were amplified from treated pools of the D2-expressing and empty vector cultures and hybridized to microarrays. Gene set enrichment analysis of these data identified genes involved in mitotic progression as required for wild-type survival in (S)-MCPG; genes involved in phosphatidylinositol biosynthesis were required for survival in the presence of D2. Both of these results present aberrant interactions that require additional research. It is expected that the method from this study will provide a platform for further investigation into the direct and off-target effects of other psychoactive drugs, in addition to the further characterization of D2 and other human receptors.

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