Signaling property study of adhesion G-protein-coupled receptors.

Adhesion G-protein-coupled receptors (GPCR) are special members of GPCRs with long N-termini containing multiple domains. We overexpressed our collection of receptors together with G-proteins in mammalian cell lines and measured the concentrations of intracellular signaling molecules, such as inositol phosphate and cAMP. Our results show that a subset of tested adhesion GPCRs has constitutive activities and is capable of coupling to a variety of G-proteins. In addition, we have identified a small molecule compound that specifically activates one of the subfamily members, GPR97, and the activation was confirmed by an independent GTPγS assay. These findings suggest classical GPCR screening assays could be applied to de-orphanize these receptors, and provide pharmacological tools to improve understanding of the physiological functions of these receptors.