DRUGS, DIMERS, AND MUTATIONS: INVESTIGATING THE EFFECTS OF LIGANDS AND A ?2-ADRENERGIC POLYMORPHISM ON HOMO/HETERODIMERIZATION OF ?2-ADRENERGIC AND ANGIOTENSIN II TYPE 1 RECEPTORS

Abstract

GPCRs are known to form dimeric structures, and this affects their pharmacological properties. The ?2AR and AT1aR are GPCRs that are involved the regulation of the adrenergic and renin-angiotensin systems. The ?2AR is polymorphic at position 164, affecting its responsiveness to adrenergic ligands. Both receptors have been shown to form dimers, but little is known on how dimerization affects their trafficking and signalling following ligand treatments. Plasma membrane localization, arrestin-2 recruitment, and G-protein interactions were determined between receptor dimers using molecular biological techniques. This study demonstrates that the formation of heterodimers can change the expected response to ligand treatments, along with associated trafficking events. It was determined that ligands bind to dimers, resulting in conformational changes to the dimeric complexes. Both the ?2AR and AT1aR are targeted in cardiovascular disease and this research demonstrates the importance of dimerization when prescribing drug therapies to avoid potential unwanted drug side effects.