Agonist-induced formation of unproductive receptor-G12 complexes

Research output: Contribution to journalJournal articlepeer-review

  • Najeah Okashah
  • Shane C. Wright
  • Kouki Kawakami
  • Mathiasen, Signe
  • Joris Zhou
  • Sumin Lu
  • Jonathan A. Javitch
  • Asuka Inoue
  • Michel Bouvier
  • Nevin A. Lambert

G proteins are activated when they associate with G protein-coupled receptors (GPCRs), often in response to agonist-mediated receptor activation. It is generally thought that agonist-induced receptor-G protein association necessarily promotes G protein activation and, conversely, that activated GPCRs do not interact with G proteins that they do not activate. Here we show that GPCRs can form agonist-dependent complexes with G proteins that they do not activate. Using cell-based bioluminescence resonance energy transfer (BRET) and luminescence assays we find that vasopressin V2 receptors (V2R) associate with both Gs and G12 heterotrimers when stimulated with the agonist arginine vasopressin (AVP). However, unlike V2R-Gs complexes, V2R-G12 complexes are not destabilized by guanine nucleotides and do not promote G12 activation. Activating V2R does not lead to signaling responses downstream of G12 activation, but instead inhibits basal G12-mediated signaling, presumably by sequestering G12 heterotrimers. Overexpressing G12 inhibits G protein receptor kinase (GRK) and arrestin recruitment to V2R and receptor internalization. Formyl peptide (FPR1 and FPR2) and Smoothened (Smo) receptors also form complexes with G12 that are insensitive to nucleotides, suggesting that unproductive GPCR-G12 complexes are not unique to V2R. These results indicate that agonist-dependent receptor-G protein association does not always lead to G protein activation and may in fact inhibit G protein activation.

Original languageEnglish
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number35
Pages (from-to)21723-21730
Number of pages8
Publication statusPublished - 1 Sep 2020
Externally publishedYes

Bibliographical note

Funding Information:
ACKNOWLEDGMENTS. We thank Steve Ikeda, Kevin Pfleger, Philip Wede-gaertner, and Bryan Roth for providing plasmid DNA used in this study. We thank Kayo Sato, Shigeko Nakano, and Ayumi Inoue (Tohoku University) for their assistance with plasmid preparation, maintenance of cell culture and cell-based GPCR assays. This work was supported by grants from the NIH (GM130142 [to N.A.L.], MH54137 [to J.A.J.]) and a Ruth L. Kirschstein National Research Service Award Individual Fellowship (GM131672 [to N.O.]). A.I. was funded by the PRIME JP17gm5910013 and the LEAP JP17gm0010004 from the Japan Agency for Medical Research and Development, and Grants-in-aid for Scientific Research (KAKENHI) 17K08264 from the Japan Society for the Promotion of Science (JSPS). K.K. is supported by JSPS Fellows 19J11256. S.C.W. is supported by a fellowship from the Swedish Society for Medical Research (P18-0098). M.B. is funded by the Canadian Institutes of Health Research (FDN-148431) and holds a Canada Research Chair in Signal Transduction and Molecular Pharmacology.

Publisher Copyright:
© 2020 National Academy of Sciences. All rights reserved.

    Research areas

  • Arrestin, G protein-coupled receptor, GPCR, Ternary complex

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