Beta-3 adrenergic receptor (ADRB3)

Beta-3 adrenergic receptor Overview

The Beta-3 adrenergic receptor (β3-adrenoceptor), encoded by the ADRB3 gene, is a member of the beta-adrenergic receptor family. It is a 7-transmembrane domain G protein-coupled receptor primarily expressed in adipose tissue, urinary bladder, and to a lesser extent in the central nervous system and gallbladder. It mediates the actions of catecholamines like epinephrine and norepinephrine. Primary functions include enhancement of lipolysis in adipose tissue, regulation of thermogenesis, and relaxation of urinary bladder smooth muscle. Activation leads to Gs protein stimulation of adenylate cyclase and increased cAMP. It is a therapeutic target for overactive bladder, with agonists like Mirabegron and Vibegron approved for treatment. Investigational uses include metabolic disorders, neurodegenerative diseases (Alzheimer's), and cardiovascular applications (heart failure). Agonists generally have favorable safety profiles with common side effects including headaches, constipation, rhinitis, and blurred vision.

Mechanism of Action

Agonist binding to the Beta-3 adrenergic receptor leads to stimulation of adenylate cyclase through G proteins of the Gs type, resulting in increased intracellular cAMP levels and subsequent activation of downstream signaling pathways. In overactive bladder, agonists relax detrusor smooth muscle.

Biological Functions

Safety Considerations

Interacting Drugs