title: The molecular evolution of the interleukin-1 family of cytokines; IL-18 in teleost fish.
abstract: The cytokine network is an important homeostatic system with potent activities in immune surveillance, growth, developmental and repair processes. Although interleukin-1beta (IL-1beta) is considered a pivotal pro-inflammatory cytokine, merely focussing on its inflammatory role would be too narrow an approach. Elucidation of the human, the mouse and the Fugu rubripes (pufferfish) genome now enables a more comprehensive overview of this cytokine family and its receptors in several vertebrate classes. Phylogenetic analyses of the IL-1 family members, comprising over 80 sequences of various fish, amphibian, avian and mammalian species, reveal that for only a few mammalian IL-1 family members unambiguous orthologues have been found in fish, indicating a recent origin of some of the mammalian IL-1 family members. Interestingly, the Fugu genome did reveal teleost orthologues for IL-18 and its putative receptor complex. All teleost IL-1beta sequences cluster separately from IL-1beta sequences of other species. In contrast, a number of IL-1 receptor family members have well conserved fish orthologues. This supports the concept of an ancestral role of this family, possibly in the brain.
authors.affiliation: Cell Biology and Immunology Group, Wageningen Institute of Animal Sciences, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: Mark O
authors.initials: MO
authors.lastname: Huising
authors.forename: René J M
authors.initials: RJ
authors.lastname: Stet
authors.forename: Huub F J
authors.initials: HF
authors.lastname: Savelkoul
authors.forename: B M Lidy
authors.initials: BM
authors.lastname: Verburg-van Kemenade
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D020169:Caspases / Q000235:genetics; D017124:Conserved Sequence; D019143:Evolution, Molecular; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D020382:Interleukin-18 / Q000235:genetics*; D053727:Interleukin-18 Receptor alpha Subunit; D007448:Invertebrates / Q000235:genetics / Q000276:immunology; D008024:Ligands; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D011110:Polymorphism, Genetic; D018123:Receptors, Interleukin / Q000235:genetics; D017472:Receptors, Interleukin-1 / Q000235:genetics; D053724:Receptors, Interleukin-18; D017386:Sequence Homology, Amino Acid; D023741:Takifugu / Q000235:genetics* / Q000276:immunology*; D015027:Zebrafish / Q000235:genetics / Q000276:immunology
chemical_list: C508572:IL18R1 protein, human; C508573:Il18r1 protein, mouse; D007375:Interleukin-1; D020382:Interleukin-18; D053727:Interleukin-18 Receptor alpha Subunit; D008024:Ligands; D018123:Receptors, Interleukin; D017472:Receptors, Interleukin-1; D053724:Receptors, Interleukin-18; D020169:Caspases