Cloning and characterization of feline brain natriuretic peptide

Brain (B-type) natriuretic peptide (BNP) is a cardiac hormone involved in regulation of fluid balance and blood pressure homeostasis of mammalian species. BNP sequence is species-specific and considered to be a significant prognostic and diagnostic marker for cardiac dysfunction. Using conventional polymerase chain reaction and amplification of cDNA 3′- and 5′-ends, a total of 1500 nucleotides encompassing the entire feline BNP gene were characterized. The feline BNP gene is organized in three exons separated by two introns. The complete transcript of 736 nucleotides was characterized, including 396 nucleotides encoding feline preproBNP. The preproBNP consisted of a signal peptide of 26 amino acids and a proBNP of 106 residues. The predicted mature BNP comprised 35 amino acids with likely 26- and 29-aa isomers, including a histidine residue at the C-terminus. Based on the similarity of BNP prepropeptide sequences, a phylogenetic relationship is presented for mammalian species including human, cat, cattle, dog, mouse, rat, sheep and swine.