Beta-adrenergic receptor (βAR)

The Beta-adrenergic receptor is a family of G protein-coupled receptors (GPCRs) important for transmembrane signaling and a significant drug target. It consists of three subtypes: beta-1 (β1), beta-2 (β2), and beta-3 (β3), which have distinct tissue distributions and functions. These receptors are transmembrane glycoprotein structures with characteristic 7TM helices. Upon ligand binding, they typically couple to the Gs G-protein, activating adenylyl cyclase and increasing intracellular cAMP, which leads to PKA activation. β1 receptors are primarily in the heart and cerebral cortex, mediating cardiac effects. β2 receptors are found widely, including airway smooth muscles, mediating bronchodilation. β3 receptors are involved in lipolysis. Beta-adrenergic receptors are targeted by various drugs, including agonists and antagonists with varying subtype selectivity, used in conditions like cardiovascular diseases (heart failure, hypertension), respiratory diseases (asthma, COPD), and potentially pulmonary arterial hypertension. Safety considerations include the need for caution when modulating the system, especially in diseases where compensatory mechanisms might be disrupted.

Other names

BAR

Ligand binding induces conformational change, enabling interaction with Gs G-protein. This activates Gs-alpha subunit by exchanging GDP for GTP, leading to dissociation. Gs-alpha activates adenylyl cyclase, increasing cAMP levels and activating protein kinase A (PKA).