Molecular cloning and expression of rat bradykinin B1 receptor

The gene encoding rat bradykinin B-1 receptor has been cloned by using a partial rat B-1 cDNA probe. The rat B-1 receptor gene contains two exons and the entire coding region is within the second exon. The 5'-flanking region of the rat B-1 receptor gene contains several putative transcriptional regulatory sites including TATA box, cAMP response element, NF-KB and AP-I. It showed promoter activity inducible by lipopolysaccharide in vascular smooth muscle cells. Rat B-1 receptor mRNA was found to be alternatively spliced and induced by lipopolysaccharide treatment in a wide range of tissues, such as the salivary gland, testis, kidney, lung, heart, prostate and aorta. The deduced rat B-1 receptor amino acid sequence is 71% homologous to human and rabbit counterparts, and 89% homologous to the mouse counterpart. The expressed B-1 receptor in HEK293 cells displayed a rank order of affinity for the kinin peptides: des-Arg(9)-BK > Lys-des-Arg(9)-BK approximate to des-Arg(9),Leu(8)-BK > Sar-Tyr-epsilon Ahx-Lys-[D-beta Nal(7),Ile(8)]-des-Arg(9)-BK > Sar-Tyr-epsilon Ahx-Lys-des-Arg(9)-BK much greater than BK much greater than Hoe140. These results indicate that the cloned gene encodes a functional rat B-1 receptor. (C) 1998 Elsevier Science B.V. All rights reserved.