Cloning, structural characterization and functional expression of a zebrafish bradykinin B2-related receptor.
The actions of bradykinin (BK) in mammals are mediated through the activation of the B1 and B2 BK receptors. The only BK receptor that has been cloned from a non-mammalian species is a B2-like receptor from the chicken (termed the ornithokinin receptor). Pharmacological studies have demonstrated the presence of BK receptors in tissues of teleost fishes, such as trout and cod, but the ligand-binding properties of these receptors differ appreciably from those of the mammalian and chicken receptors. We report here the cloning of a B2-like receptor in zebrafish that shares 35% identity with human B2 and 30% identity with human B1. Phylogenetic analyses confirm a closer relationship with B2 than B1. The receptor gene was mapped to linkage group 17, which is syntenic to the human B2-B1 gene region. After functional expression of the zebrafish B2 receptor in mammalian cells, nanomolar concentrations of trout BK ([Arg0,Trp5,Leu8]-BK) and the derivative [des-Arg0,Trp5,Leu8]-BK (where 'des' indicates a missing amino acid) induced a significant transient rise in intracellular free Ca2+. The B1-selective analogue [Arg0,Trp5,Leu8,des-Arg9]-BK was inactive at nanomolar concentrations. Taken together, these results strongly support the gene's identity as a piscine orthologue of the mammalian B2 receptor.
Dunér
Torun
T
Department of Neuroscience, Unit of Pharmacology, Uppsala University, P.O. Box 593, SE-751 24 Uppsala, Sweden.
Conlon
J Michael
JM
Kukkonen
Jyrki P
JP
Akerman
Karl E O
KE
Yan
Yi-Lin
YL
Postlethwait
John H
JH
Larhammar
Dan
D
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017931:DNA Primers; D005786:Gene Expression Regulation; D005822:Genetic Vectors; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D043782:Receptor, Bradykinin B2; D018002:Receptors, Bradykinin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D015027:Zebrafish / Q000235:genetics*
D017931:DNA Primers; D043782:Receptor, Bradykinin B2; D018002:Receptors, Bradykinin; D011994:Recombinant Proteins