Spatiotemporal regulation of Rap guanine nucleotide exchange factors

Guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs) orchestrate the activity of small G-proteins. In response to extracellular stimuli, GEFs and GAPs activate signaling cascades regulated by G-proteins by controlling their regulation in time and in space. Generally, GEFs function as activators of G-proteins by promoting their GTP-bound state while GAPs serve as inhibitors by increasing the rate of GTP hydrolysis. Our understanding of the mechanisms of regulation of signal transduction networks by GEFs and GAPs is still growing. In this Ph.D. thesis we try to address this issue by focusing on exchange factors for the small G-protein Rap.