title: Structural and functional evolution of three cardiac natriuretic peptides.
abstract: Natriuretic peptides (NPs) are a group of hormones playing important roles in cardiovascular and osmoregulatory systems in vertebrates. Among the NP subtypes, atrial NP (ANP), B-type NP (BNP), and ventricular NP (VNP) are circulating hormones expressed exclusively in the heart (cardiac NPs). The constitution of cardiac NPs is variable among species of vertebrates. In order to understand the evolutionary and functional significance of such variation, we performed a systematic survey of cardiac NP cDNAs in nine taxonomically diverse teleosts inhabiting environments of varying salinity. The discovery of the coexistence of the ANP, BNP, and VNP genes in the eel and rainbow trout suggested that the ancestral teleost had all three cardiac NPs. As the VNP cDNA was undetectable in ayu and six species of Neoteleostei, it is possible that VNP was lost before the divergence of Osmeroidei. The ANP gene was also undetectable in the medaka. Thus, only the BNP gene is universal in species examined in the present study. Synthetic medaka BNP preferentially activated two medaka GC-A-type receptors, suggesting that the three cardiac NPs share the same receptor. However, the regulation of BNP expression may be the most strict because ATTTA repeats in the 3'-untranslated region and the dibasic motif in the ring are conserved among teleosts and tetrapods. Linkage analyses in the rainbow trout located ANP, BNP, and VNP genes on the same chromosome, which suggested the generation of the VNP gene by tandem duplication as observed with ANP and BNP genes. If the duplication occurred before the divergence of tetrapods and teleosts, VNP may exist in the tetrapod lineage.
authors.affiliation: Ocean Research Institute, The University of Tokyo, Minamidai, Nakano, Tokyo, Japan. inouek@ori.u-tokyo.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Inoue
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Shinya
authors.initials: S
authors.lastname: Yuge
authors.forename: Hozi
authors.initials: H
authors.lastname: Iwatani
authors.forename: Sayaka
authors.initials: S
authors.lastname: Yamagami
authors.forename: Makiko
authors.initials: M
authors.lastname: Tsutsumi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hori
authors.forename: Maria Carmela
authors.initials: MC
authors.lastname: Cerra
authors.forename: Bruno
authors.initials: B
authors.lastname: Tota
authors.forename: Norio
authors.initials: N
authors.lastname: Suzuki
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Okamoto
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Takei
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000737:chemistry / Q000235:genetics; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis; D019143:Evolution, Molecular; D005399:Fishes / Q000235:genetics*; D008969:Molecular Sequence Data; D020097:Natriuretic Peptide, Brain / Q000737:chemistry / Q000235:genetics; D045265:Natriuretic Peptides / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D045265:Natriuretic Peptides; C092435:ventricular natriuretic factor, rainbow trout; D020097:Natriuretic Peptide, Brain; C068986:ventricular natriuretic peptide, eel; D009320:Atrial Natriuretic Factor