title: Cloning and functional characterization of IRAK4 in large yellow croaker (Larimichthys crocea) that associates with MyD88 but impairs NF-κB activation.
abstract: As crucial signaling transducer in Toll-like receptor (TLR) and interleukin (IL)-1 receptor (IL-1R) signaling pathway, IL-1R-associated kinase 4 (IRAK4) mediates downstream signaling cascades and plays important roles in innate and adaptive immune responses. In the present study, an IRAK4 orthologue was characterized from large yellow croaker (Larimichthys crocea), named Lc-IRAK4, with a conservative N-terminal death domain and a C-terminal protein kinase domain. The genome of Lc-IRAK4 is structured into eleven exons and ten introns. Expression analysis indicated that Lc-IRAK4 was widely expressed in tested tissues, with the highest level in liver and weakest in muscle. Additionally, in the spleen, liver tissues and blood, it could be induced by poly I:C and LPS stimulation, but not be induced by Vibrio parahemolyticus infection. Fluorescence microscopy assays revealed that Lc-IRAK4 localized in the cytoplasm in HEK 293T cells. It was also determined that Lc-IRAK4 could interact with MyD88, whereas MyD88-mediated NF-κB activation was significantly impaired when co-transfected the two in HEK 293T cells. These findings collectively indicated that although Lc-IRAK4 was evolutionarily conserved in vertebrates, the exact function especially the signaling transduction mediated by IRAK4 in fish immune response was different from that in mammals, which impaired MyD88-mediated NF-κB activation.
authors.affiliation: College of Fisheries, Jimei University, 43 Yindou Road, Xiamen, Fujian Province, 361021, China.
authors.forename: Peng Fei
authors.initials: PF
authors.lastname: Zou
authors.affiliation: College of Fisheries, Jimei University, 43 Yindou Road, Xiamen, Fujian Province, 361021, China.
authors.forename: Xue Na
authors.initials: XN
authors.lastname: Huang
authors.affiliation: College of Fisheries, Jimei University, 43 Yindou Road, Xiamen, Fujian Province, 361021, China. Electronic address: clyao@jmu.edu.cn.
authors.forename: Cui Luan
authors.initials: CL
authors.lastname: Yao
authors.affiliation: College of Fisheries, Jimei University, 43 Yindou Road, Xiamen, Fujian Province, 361021, China.
authors.forename: Qing Xue
authors.initials: QX
authors.lastname: Sun
authors.affiliation: School of Environmental Science and Engineering, Xiamen University, Tan Kah Kee College, Zhangzhou, Fujian Province, 363105, China; Key Laboratory of Estuarine Ecological Security and Environmental Health, Zhangzhou, Fujian Province, 363105, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Fisheries, Jimei University, 43 Yindou Road, Xiamen, Fujian Province, 361021, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: College of Fisheries, Jimei University, 43 Yindou Road, Xiamen, Fujian Province, 361021, China.
authors.forename: Zhen Xing
authors.initials: ZX
authors.lastname: Yu
authors.affiliation: College of Fisheries, Jimei University, 43 Yindou Road, Xiamen, Fujian Province, 361021, China.
authors.forename: Ze Jun
authors.initials: ZJ
authors.lastname: Fan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005393:Fish Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D007113:Immunity, Innate; D053592:Interleukin-1 Receptor-Associated Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D010473:Perciformes; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary; D014733:Vibrio / Q000502:physiology; D014735:Vibrio Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D008070:Lipopolysaccharides; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D012333:RNA, Messenger; D053592:Interleukin-1 Receptor-Associated Kinases; D011070:Poly I-C
keywords: IRAK4; Large yellow croaker; MyD88; NF-kappaB; Toll-like receptor