Subcellular location defines GPCR signal transduction

G protein-coupled receptors in intracellular organelles can be activated in response to membrane permeant ligands, which contributes to the diversity and specificity of agonist action. The opioid receptors (ORs) provide a striking example, where small molecule opioid drugs activate ORs in the Golgi apparatus within seconds of drug addition. To date, our knowledge on the signaling of intracellular GPCRs remains incomplete and it is unknown if the downstream events triggered by ORs in plasma membrane and Golgi apparatus differ. To address this gap, we analyzed OR-mediated gene expression changes upon treatment with impermeant peptide ligand DPDPE, permeant ligand SNC80 or ICI-SNC80 (Golgi-restricted signaling). We show that DOR activation in the Golgi does not trigger any gene transcription at these two time points as compare to plasma membrane receptors. The study delineates OR signal transduction with unprecedented resolution and reveals that the subcellular location defines the signaling effect promoted by opioid drugs. Overall design: Comparative analysis of HEK293 gene expression profiles upon activation of OR at plasma membrane or in the Golgi using different ligands combinations. All treatments performed in triplicates.