title: Ribonucleases and angiogenins from fish.
abstract: For the first time fish RNases have been isolated and characterized. Their functional and structural properties indicate that they belong to the RNase A superfamily (or tetrapod RNase superfamily), now more appropriately described as the vertebrate RNase superfamily. Our findings suggest why previously repeated efforts to isolate RNases from fish tissues have met with no success; fish RNases have a very low ribonucleolytic activity, and their genes have a low sequence identity with those of mammalian RNases. The investigated RNases are from the bony fish Danio rerio (or zebrafish). Their cDNAs have been cloned and expressed, and the three recombinant proteins have been purified to homogeneity. Their characterization has revealed that they have indeed a very low RNA-degrading activity, when compared with that of RNase A, the superfamily prototype, but comparable with that of mammalian angiogenins; that two of them have angiogenic activity that is inhibited by the cytosolic RNase inhibitor. These data and a phylogenetic analysis indicate that angiogenic fish RNases are the earliest diverging members of the vertebrate superfamily, suggesting that ribonucleases with angiogenic activity were the ancestors of all ribonucleases in the superfamily. They later evolved into both mammalian angiogenins and, through a successful phylogenesis, RNases endowed with digestive features or with diverse bioactivities.
authors.affiliation: Department of Structural and Functional Biology, University of Naples Federico II, Complesso M. S. Angelo, Via Cintia, 80126 Napoli, Italy.
authors.forename: Elio
authors.initials: E
authors.lastname: Pizzo
authors.forename: Pasquale
authors.initials: P
authors.lastname: Buonanno
authors.forename: Antimo
authors.initials: A
authors.lastname: Di Maro
authors.forename: Salvatore
authors.initials: S
authors.lastname: Ponticelli
authors.forename: Sandro
authors.initials: S
authors.lastname: De Falco
authors.forename: Natalina
authors.initials: N
authors.lastname: Quarto
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Cubellis
authors.forename: Giuseppe
authors.initials: G
authors.lastname: D'Alessio
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009389:Neovascularization, Pathologic; D018919:Neovascularization, Physiologic; D010802:Phylogeny; D012259:Ribonuclease, Pancreatic / Q000737:chemistry* / Q000378:metabolism; D012260:Ribonucleases / Q000737:chemistry* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish
chemical_list: D012260:Ribonucleases; C046366:angiogenin; D012259:Ribonuclease, Pancreatic