Heterogeneity of Tethered Agonist Signaling in Adhesion G Protein-Coupled Receptors

Adhesion G Protein-Coupled Receptor (aGPCR) signaling influences development and homeostasis in a wide range of tissues. In the current model for aGPCR signaling, ligand binding liberates or unmasks a highly conserved tethered agonist (TA) that acts as an intramolecular ligand to stimulate G protein coupling. However, a systematic, comprehensive examination of signaling has not been performed for all aGPCR family members. Here, we report a platform for profiling TA-dependent activities of aGPCRs in several different assays and apply it to all 33 human family members. Activity profiling identified a heterogeneity of responses among these aGPCRs, with only [~]50% showing robust, TA-dependent signals. AlphaFold2 predictions assessing TA engagement in the predicted intramolecular binding pocket aligned with the TA-dependence of the cellular responses. The signaling information in this dataset is a comprehensive resource relevant for the investigation of all human aGPCRs and for targeting aGPCRs therapeutically.