Dr. Corinne Lutomski presents > “Connecting Proteoform Diversity to Biased Signaling using Native Top-down MS of GPCR’s”
G protein-coupled receptors (GPCRs) are responsible for activating intracellular signaling cascades given a range of extracellular stimuli. GPCR function is further diversified by post-translational modifications which regulate selectivity of ligands and interactions with downstream effectors. Current bottom-up -omics techniques provide valuable catalogues of GPCR proteoforms and lists of interacting partners, however, missing from this toolkit is a robust workflow to define the direct interaction between ligands and the specific proteoforms that lead to distinct cell physiology. Here, we describe a method for native top-down mass spectrometry capable of (i) liberating intact membrane receptors from detergent micelles while preserving noncovalent associations and (ii) multistage tandem mass spectrometry (MSn) to sequence GPCR proteoforms and their ligands, enabling connections to be made between GPCR proteoforms and specific cell signaling responses.