The structure and dynamics of proteins determines the mechanisms by which signals are transmitted in cells. Our laboratory especially characterizes the structures and the dynamics of proteins involved in protein-protein interactions. Understanding the molecular determinants that are responsible for signal transduction is important as this knowledge will allow us to gain insight into how the normal function of signaling proteins is disrupted by mutations in diseased states. Knowing at near-atomic resolution which residues interact in protein complex formation will allow us to rationalize their interaction affinity and specificity. Furthermore, it will provide an opportunity for us to alter the proteins for diagnostic or therapeutic purposes. Fundamentally, we will gain a deep insight into how proteins are used for signaling in the specific systems.