Yeast double transporter-gene deletion library for identification of xenobiotic carriers

The routes of uptake and efflux should be considered when developing new drugs so that they can effectively address their intracellular targets. In general rule, drugs appear to enter cells via protein carriers that normally carry nutrients or metabolites. A previously developed pipeline that searched for drug transporters using Saccharomyces cerevisiae mutants carrying single-gene deletions identified import routes for most compounds tested. However, due to the redundancy of transporter functions, we proposed that this methodology could be improved by utilizing double-mutant strains in both low- and high-throughput screens. We constructed a library of over 14,000 strains harboring double-deletions of 122 non-essential genes encoding plasma membrane transporters and performed high-throughput screens to identify possible drug import and efflux routes for 23 compounds.