MOLECULAR-CLONING AND EXPRESSION OF RAT BRADYKININ B-1 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'-f lanking region of the rat B-1 receptor gene contains several putative transcriptional regulatory sites including TATA box, cAMP response ele ment, NF-KB and AP-I. It showed promoter activity inducible by lipopol ysaccharide in vascular smooth muscle cells. Rat B-1 receptor mRNA was found to be alternatively spliced and induced by lipopolysaccharide t reatment in a wide range of tissues, such as the salivary gland, testi s, kidney, lung, heart, prostate and aorta. The deduced rat B-1 recept or amino acid sequence is 71% homologous to human and rabbit counterpa rts, and 89% homologous to the mouse counterpart. The expressed B-1 re ceptor in HEK293 cells displayed a rank order of affinity for the kini n 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 enco des a functional rat B-1 receptor. (C) 1998 Elsevier Science B.V. All rights reserved.