G Protein-Coupling of Adhesion GPCRs ADGRE2/EMR2 and ADGRE5/CD97, and Activation of G Protein Signalling by an Anti-EMR2 Antibody

• Published in: Scientific reports 2020-01, Vol.10 (1), p.1004-1004, Article 1004
• Main Authors: Bhudia, Nisha, Desai, Sapna, King, Natalie, Ancellin, Nicolas, Grillot, Didier, Barnes, Ashley A., Dowell, Simon J.
• Format: Article
• Language: English
• Subjects: 631/154; 631/1647; 631/250; 631/45; 631/67; 631/80; Adhesion; Antibodies - immunology; Antigens, CD - metabolism; Biological effects; Blotting, Western; Chimeras; Cyclic AMP; G protein-coupled receptors; GTP-Binding Proteins - metabolism; HEK293 Cells - metabolism; Humanities and Social Sciences; Humans; Immunoprecipitation; Mammalian cells; multidisciplinary; NF-AT protein; Pertussis; Polyclonal antibodies; Proteins; Receptors, G-Protein-Coupled - antagonists & inhibitors; Receptors, G-Protein-Coupled - immunology; Receptors, G-Protein-Coupled - metabolism; Science; Science (multidisciplinary); Signal Transduction - drug effects; Toxins; Yeasts
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-57989-6

The experimental evidence that Adhesion G Protein-Coupled Receptors (aGPCRs) functionally couple to heterotrimeric G proteins has been emerging in incremental steps, but attributing biological significance to their G protein signalling function still presents a major challenge. Here, utilising activated truncated forms of the receptors, we show that ADGRE2/EMR2 and ADGRE5/CD97 are G protein-coupled in a variety of recombinant systems. In a yeast-based assay, where heterologous GPCRs are coupled to chimeric G proteins, EMR2 showed broad G protein-coupling, whereas CD97 coupled more specifically to G α12 , G α13 , G α14 and G αz chimeras. Both receptors induced pertussis-toxin (PTX) insensitive inhibition of cyclic AMP (cAMP) levels in mammalian cells, suggesting coupling to G αz . EMR2 was shown to signal via G α16 , and via a G α16 /G αz chimera, to stimulate IP 1 accumulation. Finally, using an NFAT reporter assay, we identified a polyclonal antibody that activates EMR2 G protein signalling in vitro . Our results highlight the potential for the development of soluble agonists to understand further the biological effects and therapeutic opportunities for ADGRE receptor-mediated G protein signalling.