Calcium-mediated modulation of the quaternary structure and function of adenosine A2A-dopamine D2 receptor heteromers

The adenosine A2A-dopamine D2 receptor heteromer is one of the most studied receptor heteromers. It has important implications for basal ganglia function and pathology. Recent studies using Bioluminescence and Sequential Resonance Energy Transfer techniques shed light on the role of Ca2+ in the modulation of the quaternary structure of the A2A-D2 receptor heteromer, which was found to depend on the binding of calmodulin (CaM) to the carboxy-terminus of the A2A receptor in the A2A-D2 receptor heteromer. Importantly, the changes in quaternary structure correlate with changes in function. A Ca2+/CaM-dependent modulation of MAPK signaling upon agonist treatment could be observed in cells expressing A2A-D2 receptor heteromers. These studies provide a first example of a Ca2+-mediated modulation of the quaternary structure and function of a receptor heteromer.