Adenosine A2a Receptor (ADORA2a)

ADORA2a is a member of the G protein-coupled receptor (GPCR) family which possess seven transmembrane alpha helices. The crystallographic structure of the adenosine A_2A receptor PDB 3EML (see figure to the right) reveals a ligand binding pocket distinct from that of other structurally determined GPCRs.

Adenosine A2a Receptoris one of several receptor subtypes for adenosine. The activity of the encoded protein, a G protein-coupled receptor family member, is mediated by G proteins which activate adenylyl cyclase. The encoded protein is abundant in basal ganglia, vasculature and platelets and it is a major target of caffeine.As with the A₁, the A_2A receptors are believed to play a role in regulating myocardial oxygen consumption and coronary blood flow.