Adenosine A3 Receptor (ADORA3)

The adenosine A3 receptor (ADORA3) is a G protein-coupled receptor that primarily couples to Gi and Gq proteins. It plays diverse roles in intracellular signaling pathways and physiological functions. ADORA3 is notably overexpressed in inflammatory cells and various cancer cells compared to normal tissues, making it an attractive therapeutic target for diseases involving inflammation or malignancy. Its activity generally results in inhibition of adenylyl cyclase via Gi coupling but can also involve other downstream pathways depending on cellular context.

Agonist binding induces conformational changes in transmembrane helices TM5-TM7, facilitating G protein coupling/activation. Phosphorylation at serines/threonines leads to rapid desensitization after activation.