title: Discovery of zebrafish (Danio rerio) interleukin-23 alpha (IL-23α) chain, a subunit important for the formation of IL-23, a cytokine involved in the development of Th17 cells and inflammation.
abstract: This paper reports the cloning and sequencing of interleukin (IL)-23 p19 subunit for the first time within a non-mammalian species, the zebrafish (Danio rerio), which was discovered using a synteny approach. In addition, amino acid sequences were for IL-23 p19 subunits were also predicted from the stickleback, Fugu and Tetraodon genomes and included in this investigation. The zebrafish IL-23 p19 cDNA consisted of a 66bp 5' UTR, a 249bp 3' UTR and a single open reading frame of 567bp giving a predicted 188 aa IL-23 p19 molecule. Multiple alignment of zebrafish IL-23 p19, with other known IL-23 p19 and IL-12 p35 amino acid sequences revealed areas of amino acid conservation, such as the presence of four predicted α-helixes, cysteines important for disulphide bond formation and the conservation of a tryptophan known to interact with the receptor. Amino acid homologies and phylogenetic analysis confirmed the relationship of the fish IL-23 p19 subunits with their mammalian homologues. All the teleost fish IL-23 p19 subunits were found to have 4 exons and 3 introns similar to that of human and mouse IL-23 p19 and a limited degree of synteny was found between the organisms for the regions containing the IL-23 p19 genes with only PAB-dependent poly(A)-specific ribonuclease subunit 2 (PAN2) and IL-23 p19 found in the same order on human chromosome 12 and all the fish genomes looked at. Lastly using real-time PCR, constitutive expression of IL-12 p40 and IL-23 p19 was observed in the kidney, liver, gut and muscle with IL-12 p40 expression higher than IL-23 p19. As soon as an hour after stimulation with LPS, there was an increase of IL-23 p19 in zebrafish leukocytes and an increase of IL-1β, IL-12 p40 and IL-23 p19 expression was found after infection of zebrafish for 1 or 6 days with Mycobaterium marinum strain E11.
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, Zoology Building, University of Aberdeen, Aberdeen, AB24 2TZ, UK.
authors.forename: Amy
authors.initials: A
authors.lastname: Holt
authors.forename: Suman
authors.initials: S
authors.lastname: Mitra
authors.forename: Astrid M
authors.initials: AM
authors.lastname: van der Sar
authors.forename: Ayham
authors.initials: A
authors.lastname: Alnabulsi
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Secombes
authors.forename: Steve
authors.initials: S
authors.lastname: Bird
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics; D003001:Cloning, Molecular; D020869:Gene Expression Profiling; D054884:Host-Pathogen Interactions; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D053760:Interleukin-23 Subunit p19 / Q000145:classification / Q000235:genetics*; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D019910:Mycobacterium marinum / Q000502:physiology; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D026801:Synteny; D058504:Th17 Cells / Q000378:metabolism*; D015027:Zebrafish / Q000235:genetics*; D029961:Zebrafish Proteins / Q000235:genetics*
chemical_list: D018836:Inflammation Mediators; D053760:Interleukin-23 Subunit p19; D008070:Lipopolysaccharides; D029961:Zebrafish Proteins