Bradykinin receptor B2

Bradykinin receptor B2 is a is_associated_with::G-protein coupled receptor for is_associated_with::bradykinin, encoded by the BDKRB2 is_associated_with::gene in humans.

Mechanism
The B2 receptor is a is_associated_with::G protein-coupled receptor, probably coupled to Gq and Gi. Gq stimulates is_associated_with::phospholipase C to increase is_associated_with::intracellular free is_associated_with::calcium and Gi inhibits is_associated_with::adenylate cyclase. Furthermore, the receptor stimulates the is_associated_with::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 (A1-7) also potentiates bradykinin action on B2 receptors.

is_associated_with::Kallidin also signals through the B2 receptor. An antagonist for the receptor is Hoe 140 (is_associated_with::icatibant).

Function
The 9 is_associated_with::amino acid bradykinin is_associated_with::peptide elicits many responses including is_associated_with::vasodilation, is_associated_with::edema, is_associated_with::smooth muscle spasm and is_associated_with::pain fiber stimulation.

Gene
Alternate start codons result in two isoforms of the protein.