Abstract 1255 Deciphering complexity of GPCR signaling in health and disease

Activation of G protein coupled receptors (GPCRs) exerts an enormous diversity of physiological effects on cells. How GPCRs encode such complexity of signals and how it goes awry in disease is poorly understood. To enable deciphering signaling logic of GPCRs, we have developed scalable approaches where we study GPCR action by real time optical recordings based on monitoring Bioluminescent Resonance Energy Transfer (BRET) in reconstituted HEK293 cells in real time. With these approaches we probed the diversity of G protein subunits in transducing signals analyzing activity of hundreds of GPCRs on 14 G 4G and 12 G subunits in all combinations from various intracellular sites. Furthermore, we profiled the activities of all Regulator of G protein Signaling (RGS) proteins on all of their possible G substrates. These studies build a systematic map of GPCR signaling network and documented unique profiles of G protein engagement by GPCRs and negative control by RGS proteins forming characteristic "fingerprints" with distinct spatiotemporal bias. We further extensively explored pharmacogenomics implications of this diversity by studying the effects of drugs, variants and disease mutations in GPCRs, RGS, and G protein subunits. In particular, a significant emphasis is made on how alterations in GPCR signaling contributes to genetic form of neurodevelopmental movement disorders. The results obtained in these studies revealed novel insights into GPCR biology, pharmacology and understanding the disease mechanisms. This work was supported by grants from NIH.