Cloning, sequence analysis and expression of the gene encoding the mouse bradykinin B2 receptor

The bradykinin B2 receptor (B2R) mediates most of the biological effects of kinins. In the present study, we have cloned and sequenced the gene (B2R) from a mouse embryonic stem (ES) cell genomic library. Mouse B2R is 7 kb in length containing three exons of 0.3, 0.23 and 3.7 kb separated by two introns of 2.5 and 0.41 kb. The first and second exons are noncoding while the third exon contains the full-length coding region and a long 3' noncoding region. An ATG translation start codon, TGA stop codon and a polyadenylation signal (AATAAA) were identified in the third exon. B2R encodes a protein of 41,470 Da and 366 amino acids (aa) forming seven transmembrane (TM) domains. At the aa level, B2R shares 91 and 82% sequence identity with the rat and human B2R, respectively. In the 5' flanking region, a consensus TATA box, a putative cAMP-response element, a putative phorbol ester-response element, a putative AP-1-binding site and a putative IL-6-response element were identified. Southern blot analysis following reverse transcription and PCR showed that B2R is expressed in most mouse tissues, except the liver and spleen, which is consistent with the wide distribution of B2R activity as deduced from pharmacological studies.