This intronless gene belongs to the G-protein-coupled receptor superfamily, which includes transmembrane proteins that play a role in signal transduction across biological membranes resulting in a variety of physiological responses. The encoded protein is a beta-2 adrenergic receptor which is activated by catecholamine ligands such as adrenaline and epinephrine. The protein participates in the classical signaling pathway involving G protein, adenylyl cyclase, cAMP (3'-5'-cyclic adenosine monophosphate) and protein kinase A (PKA). In humans, this gene is implicated in susceptibility to nocturnal asthma, obesity and type 2 diabetes. [provided by RefSeq, Apr 2013]