(697g) Protein Engineering Approaches to Dissect Specificity in Cell Signaling

Cells are packed with a high density of proteins, whose interactions drive most physiological processes. Aberrant protein-protein interactions are very often implicated in many debilitating or fatal diseases such as diabetes, neurodegenerative diseases, and cancer. Cell signaling emerges from an ensemble of dynamic, transient, protein-protein interactions in crowded cellular environments. Established structural and cell biological techniques are mostly limited to addressing the function of stable protein complexes, and do not address emergent behavior stemming from multiple transient interactions. My research program centers on the concept that protein interaction networks in cells have evolved to harness multi-protein interactions, requiring in cell biochemical measurements of cellular processes and in vitro reconstitution of transient multi-protein assemblies. We use a genetically encoded technique called Systematic Protein Affinity Strength Modulation that allows us to control protein interactions both in vitro and in cells to understand the molecular mechanisms that dictate context-dependent specificity in G protein-coupled receptors (GPCRs) and kinases. I will present recent work highlighting the synergistic effects of G proteins on GPCR signaling, and the biochemical basis of substrate-specificity in protein kinases.