Eukaryotic cells use signaling pathways to control their responses to specific extracellular cues. The goal of our research is to understand the molecular mechanisms underlying these pathways and how they are organized into larger networks. Our studies focus on protein kinases, which are key enzymes in propagating cellular signas. We use a combination of molecular diversity approaches (peptide arrays, phage display, small molecule screening) and conventional cell and molecular biology to understand the mechanisms of substrate recognition by these enzymes and to probe how substrate specificity impacts biological function. One outcome of this work is the identification of new strategies and agents for pharmacological targeting of pathways relevant to disease.