National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM144965
米国
National Institutes of Health/National Center for Complementary and Integrative Health (NIH/NCCIH)
AT012075
米国
引用
ジャーナル: Nat Chem Biol / 年: 2025 タイトル: Molecular mechanisms of inverse agonism via κ-opioid receptor-G protein complexes. 著者: Aaliyah S Tyson / Saif Khan / Zenia Motiwala / Gye Won Han / Zixin Zhang / Mohsen Ranjbar / Daniel Styrpejko / Nokomis Ramos-Gonzalez / Stone Woo / Kelly Villers / Delainey Landaker / Terry ...著者: Aaliyah S Tyson / Saif Khan / Zenia Motiwala / Gye Won Han / Zixin Zhang / Mohsen Ranjbar / Daniel Styrpejko / Nokomis Ramos-Gonzalez / Stone Woo / Kelly Villers / Delainey Landaker / Terry Kenakin / Ryan Shenvi / Susruta Majumdar / Cornelius Gati / 要旨: Opioid receptors, a subfamily of G protein-coupled receptors (GPCRs), are key therapeutic targets. In the canonical GPCR activation model, agonist binding is required for receptor-G protein complex ...Opioid receptors, a subfamily of G protein-coupled receptors (GPCRs), are key therapeutic targets. In the canonical GPCR activation model, agonist binding is required for receptor-G protein complex formation, while antagonists prevent G protein coupling. However, many GPCRs exhibit basal activity, allowing G protein association without an agonist. The pharmacological impact of agonist-free receptor-G protein complexes is poorly understood. Here we present biochemical evidence that certain κ-opioid receptor (KOR) inverse agonists can act via KOR-G protein complexes. To investigate this phenomenon, we determined cryo-EM structures of KOR-G protein complexes with three inverse agonists: JDTic, norBNI and GB18, corresponding to structures of inverse agonist-bound GPCR-G protein complexes. Remarkably, the orthosteric binding pocket resembles the G protein-free 'inactive' receptor conformation, while the receptor remains coupled to the G protein. In summary, our work challenges the canonical model of receptor antagonism and offers crucial insights into GPCR pharmacology.