title: Characterization, expression, and functional study of IRAK-1 from grouper, Epinephelus coioides.
abstract: As crucial components of the toll-like receptor (TLR) and interleukin-1 (IL-1) receptor (IL-1R) signaling pathways, interleukin-1 receptor associated kinase (IRAK) family members play essential roles in an animal's immune response. In this study, an IRAK family member, designated EcIRAK-1, was identified in the orange-spotted grouper Epinephelus coioides, and its role in signal transduction investigated. The full-length EcIRAK-1 gene is 2822 bp, encoding a 760-amino-acid protein that has the typical characteristics of mammalian IRAK-1, including an N-terminal death domain, a ProST domain, a central kinase domain, and C-terminal C1 and C2 domains. EcIRAK-1 shares 42%-79% sequence identity with other fish IRAK-1 proteins, and the death and kinase domains are more conserved than the other domains. Several important amino acids and motifs of mammalian IRAK-1 are also conserved in the grouper and other piscine IRAK-1s. In healthy grouper, EcIRAK-1 was broadly expressed in all the tissues tested, with the highest expression in the gill and skin. After infection with Cryptocaryon irritans, EcIRAK-1 expression increased in the gill and spleen. After its exogenous expression in HEK293T cells, EcIRAK-1 significantly activated nuclear factor kappaB (NF-κB). The death domain, ProST domain, and some conserved amino acids, such as T58, T207, K237, and T387, in EcIRAK-1 are required for its signaling function. These data demonstrate that piscine IRAK-1 has the same structural characteristics as its mammalian counterpart and that its function is conserved among vertebrates.
authors.affiliation: College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong Province, PR China; State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, Guangdong Province, PR China.
authors.forename: Yan-Wei
authors.initials: YW
authors.lastname: Li
authors.affiliation: Key Laboratory of Fishery Drug Development, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, Guangdong Province, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhao
authors.affiliation: College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong Province, PR China.
authors.forename: Ze-Quan
authors.initials: ZQ
authors.lastname: Mo
authors.affiliation: School of Bioscience and Biotechnology, South China University of Technology, Guangzhou 510006, Guangdong Province, PR China.
authors.forename: Xiao-Chun
authors.initials: XC
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, Guangdong Province, PR China. Electronic address: lianxing@mail.sysu.edu.cn.
authors.forename: An-Xing
authors.initials: AX
authors.lastname: Li
authors.affiliation: College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong Province, PR China. Electronic address: dxm72@scau.edu.cn.
authors.forename: Xue-Ming
authors.initials: XM
authors.lastname: Dan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001492:Bass; D016798:Ciliophora / Q000502:physiology*; D016770:Ciliophora Infections / Q000235:genetics / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005393:Fish Diseases / Q000235:genetics* / Q000276:immunology / Q000469:parasitology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D053592:Interleukin-1 Receptor-Associated Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary; D015398:Signal Transduction
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D016328:NF-kappa B; D012333:RNA, Messenger; D053592:Interleukin-1 Receptor-Associated Kinases
keywords: Cryptocaryon irritans; Epinephelus coioides; IRAK-1; Signal transduction