G protein-coupled receptors (GPCRs) are the proteins responsible for transducing “outside” signals into an intracellular response and their dysfunction is implicated in many diseases. As a result, they are the target of ~40% of drugs on the market. However, many GPCR drugs elicit off-target effects and can produce unwanted effects such as receptor desensitization and/or drug dependence. Currently, the mechanism of action of many GPCR drug targets is poorly understood.
GPCRs don’t act in isolation; proteins, metabolites, and lipids, and other molecules all interact synergistically to generate distinct signaling outputs. However, conventional ‘omics’ approaches will never be able to connect the status of critical proteins with metabolites or other effectors since the links between them are broken during sample preparation. It is therefore imperative to maintain molecular interactions to understand the molecular network that contributes to a biological signaling output.
This project successfully developed state-of-the-art methods in native mass spectrometry (MS) to interrogate membrane proteins in complex with lipids, ligands, and other molecular interactors intact in the mass spectrometer. By maintaining complexes from the cell to the mass spectrometer, and by dissecting protein-effector interactions in a controlled manner, we are now better equipped to understand mechanisms of membrane protein signal transduction. Specific knowledge of how protein receptors translate “outside” signals into a biological response will change how we approach the treatment of human disease, pain, and other conditions.
