title: Interferon regulatory factors 4 and 8 in rock bream, Oplegnathus fasciatus: structural and expressional evidence for their antimicrobial role in teleosts.
abstract: The interferon regulatory factor (IRF) members IRF4 and IRF8 contribute to B-lymphocyte development and can act as regulators of immunoglobulin (Ig) light chain gene transcription. These two IRFs are closely interrelated and are expressed at high levels in the lymphoid and myeloid cells of the immune system. In this study, the complete cDNA and genomic sequences of rock bream IRF4 (RbIRF4) and IRF8 (RbIRF8) were identified by homology screening of a multi-tissue normalized cDNA library and a BAC library, respectively, which had been established using Roche 454 GS-FLX™ technology. The full-length RbIRF4 cDNA is composed of 3442 bp and encodes a polypeptide of 462 amino acids; the genomic DNA is 9262 bp in length, consisting of eight exons and seven introns. The full-length RbIRF8 cDNA is composed of 2186 bp and encodes a 422 amino acid polypeptide; the genomic DNA is 4120 bp in length, consisting of nine exons and eight introns. The deduced amino acid sequences of RbIRF4 and RbIRF8 include a conserved DNA-binding domain (DBD) encompassing a tryptophan pentad-repeat and an IRF-association domain (IAD). Several putative transcription factor binding sites were also identified in 5' flanking region of both RbIRF4 and RbIRF8, and include those of immune-related factors. Quantitative real time PCR analysis of healthy rock bream detected the highest expression levels of RbIRF4 and RbIRF8 in lymphomyeloid-rich tissues. In addition, viral (rock bream iridovirus) and bacterial (Edwardsiella tarda and Streptococcus iniae) infection stimulated RbIRF4 and RbIRF8 expressions in head kidney and spleen. These results suggest not only that RbIRF4 and RbIRF8 may have a protective function against virus and bacteria pathogen invasion in rock bream, but also that IRFs may be immunomodulatory factors of teleost fish.
authors.affiliation: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
authors.forename: S D N K
authors.initials: SD
authors.lastname: Bathige
authors.forename: Ilson
authors.initials: I
authors.lastname: Whang
authors.forename: Navaneethaiyer
authors.initials: N
authors.lastname: Umasuthan
authors.forename: Bong-Soo
authors.initials: BS
authors.lastname: Lim
authors.forename: Myoung-Ae
authors.initials: MA
authors.lastname: Park
authors.forename: Eunmi
authors.initials: E
authors.lastname: Kim
authors.forename: Hae-Chul
authors.initials: HC
authors.lastname: Park
authors.forename: Jehee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D003001:Cloning, Molecular; D004266:DNA Virus Infections / Q000276:immunology / Q000662:veterinary; D018076:DNA, Complementary; D020609:Edwardsiella tarda / Q000502:physiology; D004756:Enterobacteriaceae Infections / Q000276:immunology / Q000662:veterinary; D029941:Fish Proteins / Q000235:genetics / Q000276:immunology*; D015698:Genomic Library; D007113:Immunity, Innate; D050835:Interferon Regulatory Factors / Q000235:genetics / Q000276:immunology*; D007497:Iridoviridae / Q000502:physiology; D008070:Lipopolysaccharides / Q000276:immunology / Q000494:pharmacology; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010473:Perciformes / Q000235:genetics / Q000276:immunology*; D010802:Phylogeny; D011070:Poly I-C / Q000276:immunology; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment / Q000662:veterinary; D013290:Streptococcal Infections / Q000276:immunology / Q000662:veterinary; D013291:Streptococcus / Q000502:physiology; D000099185:Interferon Regulatory Factor-8; D000099218:Interferon Regulatory Factor-4
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D050835:Interferon Regulatory Factors; D008070:Lipopolysaccharides; D011070:Poly I-C; D000099185:Interferon Regulatory Factor-8; D000099218:Interferon Regulatory Factor-4