| Annotations |
The binding of bradykinin to the B2R endogenously expressed on PC-12 cells leads to the formation of homo dimers, while the antagonist for B2R, HOE140 does not induce dimerization, which suggests that B2R dimerization is linked to receptor activation. Addition of a peptide corresponding not to the extracellular loops but to the amino terminus of the receptor reduced the amount of B2R dimers. In contrast to the wild-type B2R and to B2R(53) that is the truncation mutant starting at amino acids 53, bradykinin did not induce dimerization of the truncation mutant of B2R(65) starting amino acids 65. Both receptor variants are similar to the wild-type B2R with respect to agonist binding and signal generation. The amino terminus of the B2R is considered to be necessary for triggering agonist-induced B2R dimerization, and receptor dimers are involved in receptor-mediated signal attenuation. |