Kinases are signaling proteins that control key cellular processes such as growth, proliferation, apoptosis, differentiation and senescence. There are several studies that present one or more kinases as key misregulated genes in human diseases. Despite their crucial role in cell-signaling and ultimately cell fate, over 25% of kinases in yeast remain uncharacterized, 10 of which have human homologs. One approach for functional characterization of kinases is to search for downstream substrates or interacting proteins. Our lab has recently developed a high-through-put genetic screen that has proven to be powerful tool for identifying novel kinase substrates. The genetic screen is designed based on the idea that overexpression of a substrate in a wild type background may not cause a growth defect, but may cause toxicity or synthetic sickness in a kinase deletion strain. This tool, known as Synthetic Dosage Lethality (SDL) screening, in conjuction with robotic synthetic genetic array technology, has been previously used in our lab to identify both known and novel substrates of Pho85, a cyclin-dependent kinase involved in cell cycle progression. Since the genome-wide SDL screen was proven fruitful for Pho85, we are performing SDL screens on all the kinases in budding yeast. To test if SDL can be successful in identifying known targets of the other kinases, we randomly chose 21 kinases and searched the literature databases to identify known targets. Each known substrate was overexpressed in both a wild type strain and its corresponding kinase delete background and the relative growth rates were assayed. Among the 21 kinases tested, 15 show an SDL phenotype with one or more previously known interacting proteins, suggesting that SDL screening can be used in a genome-wide scale for the majority of the kinases. Using such genome-wide screens, we have been able to identify both characterized substrates and several unknown interacting partners. The power of such a high-through-put robotic method allows for the generation of vast quantity of data that can be useful for the scientific community in assigning function to their kinase of interest. With this robotic technology, one can map the entire kinase interaction network in the cell and assign function to both known and putative genes.