A 2022 Nature cryo-EM study of human B2R-Gq complexes by Jinkeng Sheng et al. investigated the proximal activation mechanisms of B2R.

This hydrophobic interaction facilitates the outward movement of transmembrane domain 6 (TM6) of B2R on the cytoplasmic side of the membrane, as well as outward movement of F279, a key residue within the conserved PIF motif of GPCRs (involving proline, isoleucine and phenylalanine).

[5] Gq stimulates phospholipase C to increase intracellular free calcium and Gi inhibits adenylate cyclase.

[7] The 9 amino acid bradykinin peptide elicits several responses including vasodilation, edema, smooth muscle spasm and nociceptor stimulation.

[8] This article incorporates text from the United States National Library of Medicine, which is in the public domain.