title: Identification and functional characterization of miiuy croaker IRF3 as an inducible protein involved regulation of IFN response.
abstract: IFN regulatory factor (IRF) 3 as an important member of IRF family, is required for the host antiviral response. In mammals, IRF3 is known to be a critical player in regulating the transcription of IFN and IFN-stimulated genes (ISGs). However, only a few studies investigated the characteristics of IRF3 genes in fish. In this study, IRF3 from miiuy croaker was identified and characterized in bioinformatics and functions. Miiuy croaker IRF3 had conserved DBD, IAD and SRD domains with other vertebrates IRF3 genes, also miiuy croaker IRF3 had relatively conserved gene synteny and gene structures with other fish IRF3 genes. Evolutionary analysis showed IRF3 genes in mammals underwent positive selection, while IRF3 in fish underwent purifying selection. Expression analysis showed miiuy croaker IRF3 was expressed in all tested tissues and up-regulated expressed in infected liver and kidney; and up-regulated expression of miiuy croaker IRF3 was observed in head kidney macrophages which stimulated with poly(I:C) indicating that miiuy croaker IRF3 participated in the immune response to defense against poly(I:C) infection. Furthermore, luciferase reporter assay showed that overexpression of miiuy croaker IRF3 can activate the production of ISRE and IFNα, suggesting that miiuy croaker IRF3 acted as transcription activators in immune responses and maybe activate IFN signaling pathway. Immunofluorescence assay showed miiuy craoker IRF3 was localized in the cytoplasm in Hela cells. Overall, we systematically and comprehensively analyzed the bioinformatics and functions of miiuy croaker IRF3, which provided further insights into the transcriptional regulation of IRF3 gene in fish and valuable information for the study of evolution of IRF3 genes.
authors.affiliation: Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Shu
authors.affiliation: Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Chu
authors.affiliation: Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China.
authors.forename: Dekun
authors.initials: D
authors.lastname: Bi
authors.affiliation: Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China.
authors.forename: Yanjin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China. Electronic address: tianjunxu@163.com.
authors.forename: Tianjun
authors.initials: T
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019295:Computational Biology; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D016678:Genome; D050838:Interferon Regulatory Factor-3 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009928:Organ Specificity; D010473:Perciformes / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D016415:Sequence Alignment / Q000662:veterinary; D026801:Synteny
chemical_list: D029941:Fish Proteins; D050838:Interferon Regulatory Factor-3; D011070:Poly I-C
keywords: Antiviral response; Cellular localization; Evolutionary analysis; IRF3