{ { DISPLAYTITLE:Bradykinin receptor B2}}
Bradykinin receptor B2 is a G-protein coupled receptor for bradykinin, encoded by the BDKRB2 gene in humans.
Mechanism
The B2 receptor is a G protein-coupled receptor, probably coupled to Gq and Gi. Gq stimulates phospholipase C to increase intracellular free calcium and Gi inhibits adenylate cyclase. Furthermore, the receptor stimulates the mitogen-activated protein kinase pathways. It is ubiquitously and constitutively expressed in healthy tissues.
The B2 receptor forms a complex with angiotensin converting enzyme (ACE), and this is thought to play a role in cross-talk between the renin-angiotensin system (RAS) and the kinin–kallikrein system (KKS). The heptapeptide angiotensin (1-7) also potentiates bradykinin action on B2 receptors.
Kallidin also signals through the B2 receptor. An antagonist for the receptor is Hoe 140 (icatibant).
Function
The 9 amino acid bradykinin peptide elicits several responses including vasodilation, edema, smooth muscle spasm and nociceptor stimulation.
Gene
Alternate start codons result in two isoforms of the protein.