Activation and allosteric regulation of the orphan GPR88-Gi1 signaling complex

Chen G, Xu J, Inoue A, Schmidt M, Bai C, Lu Q, Gmeiner P, Liu Z, Du Y (2022)


Publication Type: Journal article

Publication year: 2022

Journal

Book Volume: 13

Article Number: 2375

Journal Issue: 1

DOI: 10.1038/s41467-022-30081-5

Abstract

GPR88 is an orphan class A G-protein-coupled receptor that is highly expressed in the striatum and regulates diverse brain and behavioral functions. Here we present cryo-EM structures of the human GPR88-Gi1 signaling complex with or without a synthetic agonist (1R, 2R)-2-PCCA. We show that (1R, 2R)-2-PCCA is an allosteric modulator binding to a herein identified pocket formed by the cytoplasmic ends of transmembrane segments 5, 6, and the extreme C terminus of the α5 helix of Gi1. We also identify an electron density in the extracellular orthosteric site that may represent a putative endogenous ligand of GPR88. These structures, together with mutagenesis studies and an inactive state model obtained from metadynamics simulations, reveal a unique activation mechanism for GPR88 with a set of distinctive structure features and a water-mediated polar network. Overall, our results provide a structural framework for understanding the ligand binding, activation and signaling mechanism of GPR88, and will facilitate the innovative drug discovery for neuropsychiatric disorders and for deorphanization of this receptor.

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APA:

Chen, G., Xu, J., Inoue, A., Schmidt, M., Bai, C., Lu, Q.,... Du, Y. (2022). Activation and allosteric regulation of the orphan GPR88-Gi1 signaling complex. Nature Communications, 13(1). https://dx.doi.org/10.1038/s41467-022-30081-5

MLA:

Chen, Geng, et al. "Activation and allosteric regulation of the orphan GPR88-Gi1 signaling complex." Nature Communications 13.1 (2022).

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