title: Identification of a retinoic acid-inducible gene I from grass carp (Ctenopharyngodon idella) and expression analysis in vivo and in vitro.
abstract: RIG-I (retinoic acid inducible gene-I) is a key mediator of antiviral immunity, able to couple detection of infection by RNA and DNA viruses to the induction of interferons. In the present study, a RIG-I gene from grass carp Ctenopharyngodon idella (CiRIG-I) was isolated and characterized. The full-length cDNA of CiRIG-I was of 3198 bp and encoded a polypeptide of 947 amino acids with an estimated molecular mass of 108,730 Da and a predicted isoelectric point of 5.85, including six main overlapping structural domains: two CARDs (caspase activation and recruitment domain), one ResIII (conserved restriction domain of bacterial type III restriction enzyme), one DEXDc (DEAD/DEAH box helicase domain), one HELICc (helicase superfamily c-terminal domain) and one RD (regulatory domain). The CiRIG-I mRNA was widespread expression in the tested 15 tissues by semi-quantitative RT-PCR (sqRT-PCR) assay. The CiRIG-I expressions in spleen and liver were significantly induced following grass carp reovirus (GCRV) infection. CiRIG-I mRNA expression was rapidly and significantly up-regulated in vitro after GCRV infection, and the CiRIG-I transcripts were also significantly enhanced in vitro post the synthetic double stranded RNA polyinosinic-polycytidylic potassium salt (poly(I:C)) stimulation. These results collectively suggested that CiRIG-I was an inducible protein, involved in the antiviral innate immune defense to GCRV in grass carp, and laid the foundation for the further mechanism research of RIG-I in fishes.
authors.affiliation: Northwest A&F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Yangling 712100, China.
authors.forename: Chunrong
authors.initials: C
authors.lastname: Yang
authors.forename: Jianguo
authors.initials: J
authors.lastname: Su
authors.forename: Teng
authors.initials: T
authors.lastname: Huang
authors.forename: Rongfang
authors.initials: R
authors.lastname: Zhang
authors.forename: Limin
authors.initials: L
authors.lastname: Peng
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002347:Carps / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D005393:Fish Diseases / Q000276:immunology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D007113:Immunity, Innate; D008099:Liver / Q000187:drug effects / Q000276:immunology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D012088:Reoviridae Infections / Q000276:immunology / Q000662:veterinary; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D013997:Time Factors; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000276:Adjuvants, Immunologic; D014157:Transcription Factors; D011070:Poly I-C