Understanding of how G protein-coupled receptors (GPCRs), the largest family of signaling receptors, achieve signaling specificity within cells to detect and respond to a broad range of extracellular stimuli, including hormones, odors, neurotransmitters, and light, remains incomplete. While these receptors play crucial roles in cellular signaling and are attractive targets for drug development, current knowledge predominantly focuses on canonical signaling pathways, overlooking the nuanced compartmentalization of GPCR signaling. Recent discoveries highlight the importance of 'location bias', wherein GPCRs can initiate signaling from various cellular compartments, influencing not only specificity but also the cellular response. However, existing techniques lack the precision required to study these compartment-specific signaling events comprehensively. This proposal aims to bridge this gap by developing innovative tools for precise spatiotemporal control of GPCR activation and unbiased interrogation of compartment-specific protein interactions and signaling events. Specifically, we plan to engineer GPCRs that can be activated only in specific cellular compartments, such as the plasma membrane, endosomes, or Golgi apparatus. These engineered receptors will be coupled with advanced proteomic techniques to map the protein interactions and signaling networks unique to each compartment. Through a collaborative effort leveraging protein engineering and quantitative proteomics, we seek to uncover novel mechanisms underlying compartment-specific GPCR signaling, offering insights into cellular communication and potential avenues for drug development, particularly in diseases affecting the nervous system. Ultimately, this research could lead to the development of more effective drugs targeting GPCRs and offer new insights into treating diseases.