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Updated: Aug 30, 2026

Characterization of G Protein-coupled Receptors by a Fluorescence-based Calcium Mobilization Assay
Published on: July 28, 2014
Identification of surrogate ligands for orphan G protein-coupled receptors
Shigeki Takeda1, Atsushi Yamamoto, Tomoaki Okada
1Institute for Biomolecular Science, Gakushuin University, 1-5-1 Mejiro, Tokyo 171-8588, Toshima-ku, Japan. tasuya.haga@gakushuin.ac.jp
Abstract:
We prepared fusion proteins with an alpha subunit of G protein Gi (Gi1alpha) of 26 orphan G protein-coupled receptors (GPCRs) and with Gsalpha of 10 orphan GPCRs, most of which had been identified from the human genome previously [FEBS Lett 520 (2002) 97]. Ligands for these fusion proteins were screened from a library consisting of approximately 1000 authentic compounds by measuring their effect on [35S]GTPgammaS binding to membrane preparations of insect Sf9 cells expressing these fusion proteins. Eleven compounds were found to act as surrogate agonists for a GPCR-Gsalpha and four GPCR-Gialpha fusion proteins, a compound as an inverse agonist for two GPCR-Gsalpha fusion proteins, and a compound as an endogenous agonist for a GPCR-Gialpha fusion protein.
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