title: Molecular cloning and expression of interleukin-1 receptor-associated kinase 4, an important mediator of Toll-like receptor signal pathway, from small abalone Haliotis diversicolor.
abstract: Mammal interleukin-1 receptor-associated kinases (IRAKs) have been demonstrated to play important functions in TLRs (Toll-like receptor) signal pathway and T cell proliferation, but there is less knowledge available on mollusc IRAKs. In this study, a molluscan IRAK-4 gene, saIRAK-4, was cloned for the first time from the small abalone (Haliotis diversicolor). Its full-length cDNA sequence was 2062 bp, with a 1548 bp open reading frame encoding a protein of 516 aa. The molecular mass of the deduced protein was approximately 57.8 kDa with an estimated pI of 5.23, and showed highest identity (47%) to acorn worm Saccoglossus kowalevskii. Amino acid sequence analysis revealed saIRAK-4 shares conserved signature motifs with other IRAK-4 proteins, including the death domain (DD), serine/threonine/tyrosine protein kinase domain (STYKc), protein kinases ATP-binding region signature, serine/threonine protein kinases active-site signature and prokaryotic membrane lipoprotein lipid attachment site. Quantitative real-time PCR was employed to investigate the tissue distribution of saIRAK-4 mRNA, and its expression in abalone under bacteria challenge and larvae at different developmental stages. The saIRAK-4 mRNA could be detected in all examined tissues, with the highest expression level in gills, and was up-regulated in hemocytes and gills after bacteria injection. Additionally, saIRAK-4 was constitutively expressed at all examined developmental stages. These results indicate that saIRAK-4 could respond to pathogenic infection and may play an important role in the adult abalone immune system and early innate immunity in the process of abalone larval development.
authors.affiliation: The Key Laboratory of Science and Technology for Aquaculture and Food Safety, Fisheries College, Jimei University, Xiamen, Fujian 361021, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Ge
authors.forename: Guodong
authors.initials: G
authors.lastname: Wang
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.forename: Ziping
authors.initials: Z
authors.lastname: Zhang
authors.forename: Shuhong
authors.initials: S
authors.lastname: Wang
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Zou
authors.forename: Sufen
authors.initials: S
authors.lastname: Yan
authors.forename: Yilei
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D049851:Gastropoda / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D018507:Gene Expression Regulation, Developmental / Q000276:immunology*; D053592:Interleukin-1 Receptor-Associated Kinases / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012313:RNA / Q000737:chemistry / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D016415:Sequence Alignment; D015398:Signal Transduction; D014735:Vibrio Infections / Q000276:immunology* / Q000382:microbiology; D014736:Vibrio parahaemolyticus / Q000276:immunology*
chemical_list: D012313:RNA; D053592:Interleukin-1 Receptor-Associated Kinases