beta-2 Adrenergic R/ADRB2: Proteins and Enzymes

ADRB2 is a member of the G protein-coupled receptor superfamily that is directly associated with one of its ultimate effectors, the class C L-type calcium channel Ca(V)1.2. This receptor-channel complex also contains a G protein, an adenylyl cyclase, cAMP-dependent kinase, and the counterbalancing phosphatase, PP2A. ADRB2 binds epinephrine with an approximately 30-fold greater affinity than it does norepinephrine. The assembly of the signaling complex provides a mechanism that ensures specific and rapid signaling by ADRB2. Different polymorphic forms, point mutations, and/or downregulation of ADRB2 are associated with nocturnal asthma, obesity and type 2 diabetes.