Mechanism of dopamine binding and allosteric modulation of the human D1 dopamine receptor

Abstract Dopamine is an essential neurotransmitter, which functions are mediated by five G protein-coupled receptors, dopamine D1 to D5 receptors (D1R-D5R) in mammals. Among them, D1R is the most abundantly expressed dopamine receptor in the CNS and is the central receptor mediating excitatory dopamine signaling in multiple dopaminergic pathways. Dysregulation of D1R signaling has been directly linked to Parkinson’s disease (PD), schizophrenia, and drug abuse. Due to its fundamental functions in human diseases, D1R has long been the subject of intensive drug development effort toward the treatment of neuropsychiatric diseases. Here, we report the structures of D1R-Gs complex bound to endogenous agonist dopamine and synthetic agonist SKF81297, both with positive allosteric modulator LY3154207. These structures reveal the basis of dopamine recognition, the binding and potential allosteric regulation of DRD1 PAM LY3154207, and provide structural templates for design of subtype-selective D1R ligand for drug discovery targeting DRD1 for treating various CNS diseases.