title: Expansion and molecular evolution of the interferon-induced 2'-5' oligoadenylate synthetase gene family.
abstract: The mammalian 2'-5' oligoadenylate synthetases (2'-5'OASs) are enzymes that are crucial in the interferon-induced antiviral response. They catalyze the polymerization of ATP into 2'-5'-linked oligoadenylates which activate a constitutively expressed latent endonuclease, RNaseL, to block viral replication at the level of mRNA degradation. A molecular evolutionary analysis of available OAS sequences suggests that the vertebrate genes are members of a multigene family with its roots in the early history of tetrapods. The modern mammalian 2'-5'OAS genes underwent successive gene duplication events resulting in three size classes of enzymes, containing one, two, or three homologous domains. Expansion of the OAS gene family occurred by whole-gene duplications to increase gene content and by domain couplings to produce the multidomain genes. Evolutionary analyses show that the 2'-5'OAS genes in rodents underwent gene duplications as recently as 11 MYA and predict the existence of additional undiscovered OAS genes in mammals.
authors.affiliation: Department of Biology and Molecular and Cellular Biology Program, Arizona State University, Tempe 85287-1501, USA. s.kumar@asu.edu
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: C
authors.initials: C
authors.lastname: Mitnik
authors.forename: G
authors.initials: G
authors.lastname: Valente
authors.forename: G
authors.initials: G
authors.lastname: Floyd-Smith
mesh_terms: D015088:2',5'-Oligoadenylate Synthetase / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12; D019143:Evolution, Molecular; D020440:Gene Duplication; D006801:Humans; D007372:Interferons / Q000502:physiology; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D011161:Porifera; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014714:Vertebrates
chemical_list: D007372:Interferons; D015088:2',5'-Oligoadenylate Synthetase