Structure and chromosomal localization of the gene (BDKRB2) encoding human bradykinin B2 receptor

The bradykinin B2 receptor (BDKRB2) has high affinity for the intact kinins, which mediate a wide spectrum of biological effects, including pain, inflammation, vasodilation, and smooth muscle contraction and relaxation. In the present study, we have cloned and sequenced the gene encoding human bradykinin B2 receptor from a human genomic library. The B2 receptor gene contains three exons separated by two introns. The first and second exons are noncoding, while the third exon contains the full-length coding region, which encodes a protein of 364 amino acids forming 7 transmembrane domains. The human B2 gene shares high sequence identity with rat and mouse B2 receptor genes and significant similarity with the gene encoding the angiotensin II type I receptor in the nucleotide sequence and exon-intron arrangement. In the 5' flanking region, a consensus TATA box and several putative transcription factor-binding sites have been identified. Genomic Southern blot analysis showed that the B2 receptor is encoded by a single-copy gene that was localized to chromosome 14q32 by in situ hybridization. In a Southern blot analysis following reverse transcription and polymerase chain reaction, the human B2 receptor was found to be expressed in most human tissues.