title: Enzymatically active 2',5'-oligoadenylate synthetases are widely distributed among Metazoa, including protostome lineage.
abstract: 2',5'-Oligoadenylate synthetases (OASs) belong to the nucleotidyl transferase family together with poly(A) polymerases, CCA-adding enzymes and the recently discovered cyclic-GMP-AMP synthase (cGAS). Mammalian OASs have been thoroughly characterized as components of the interferon-induced antiviral system. The OAS activity and the respective genes were also discovered in marine sponges where the interferon system is absent. In this study the recombinant OASs from several multicellular animals and their closest unicellular relative, a choanoflagellate, were expressed in a bacterial expression system and their enzymatic activities were examined. We demonstrated 2-5A synthesizing activities of OASs from the marine sponge Tedania ignis, a representative of the phylogenetically oldest metazoan phylum (Porifera), from an invertebrate of the protostome lineage, the mollusk Mytilus californianus (Mollusca), and from a vertebrate species, a cartilaginous fish Leucoraja erinacea (Chordata). However, the expressed proteins from an amphibian, the salamander Ambystoma mexicanum (Chordata), and from a protozoan, the marine choanoflagellate Monosiga brevicollis (Choanozoa), did not show 2-5A synthesizing activity. Differently from other studied OASs, OAS from the marine sponge T. ignis was able to catalyze the formation of oligomers having both 2',5'- and 3',5'-phosphodiester linkages. Our data suggest that OASs from sponges and evolutionarily higher animals have similar activation mechanisms which still include different affinities and possibly different structural requirements for the activating RNAs. Considering their 2'- and 3'-specificities, sponge OASs could represent a link between evolutionarily earlier nucleotidyl transferases and 2'-specific OASs from higher animals.
authors.affiliation: Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia.
authors.forename: Mailis
authors.initials: M
authors.lastname: Päri
authors.affiliation: Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia.
authors.forename: Anne
authors.initials: A
authors.lastname: Kuusksalu
authors.affiliation: Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia.
authors.forename: Annika
authors.initials: A
authors.lastname: Lopp
authors.affiliation: Department of Molecular Biology, Aarhus University, C.F. Møllers Allé 3, 8000 Aarhus, Denmark.
authors.forename: Karina Hansen
authors.initials: KH
authors.lastname: Kjaer
authors.affiliation: Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Allé 130, 8000 Aarhus C, Denmark.
authors.forename: Just
authors.initials: J
authors.lastname: Justesen
authors.affiliation: Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia. Electronic address: merike.kelve@ttu.ee.
authors.forename: Merike
authors.initials: M
authors.lastname: Kelve
mesh_terms: D015088:2',5'-Oligoadenylate Synthetase / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D000558:Ambystoma mexicanum / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D056897:Choanoflagellata / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D049878:Mytilus / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D009713:Nucleotidyltransferases / Q000145:classification / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011161:Porifera / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D009713:Nucleotidyltransferases; D015088:2',5'-Oligoadenylate Synthetase
keywords: 2-5A; 2′,5′-Oligoadenylate synthetase; 2′,5′-oligoadenylate; 2′,5′-oligoadenylate synthetase; Choanoflagellate; Nucleotidyl transferase; OAS; OAS-like protein; OASL; PAP; Porifera; Protostomia; RNaseL; cGAS; cyclic-GMP-AMP synthase; double-stranded RNA; dsRNA; latent RNase; poly(A) polymerase