My project is aimed at identifying novel phosphoprotein substrates for all non-essential kinases in Saccharomyces cerevisiae. To this end, we are using a high-throughput genomics approach, i.e. synthetic genetic array (SGA) based screens, to explore the yeast kinome. The approach is based on the premise that over-expression of a negatively regulated kinase substrate may cause a growth defect in the absence of its regulatory kinase. This approach has successfully been employed to identify new substrates for the Pho85 kinase.

An array of strains carrying plasmids with unique GAL1-10 driven yeast genes is crossed to a query kinase mutant.  Through a series of selection steps, haploids are generated and are grown on medium containing galactose to induce expression of the unique ORFs. The over-expressed genes that confer slow growth phenotypes, also referred to as synthetic dosage lethality (SDL), are subsequently used for further analysis which includes protein-protein interactions and in vitro kinase assays.