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

Fish Shellfish Immunol. Apr-May 2011;30(4-5):1138-46. doi: 10.1016/j.fsi.2011.02.018. Epub 2011 Mar 17.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • Gastropoda / enzymology*
  • Gastropoda / genetics
  • Gastropoda / immunology
  • Gastropoda / microbiology
  • Gene Expression Regulation, Developmental / immunology*
  • Interleukin-1 Receptor-Associated Kinases / biosynthesis
  • Interleukin-1 Receptor-Associated Kinases / genetics
  • Interleukin-1 Receptor-Associated Kinases / immunology*
  • Molecular Sequence Data
  • Phylogeny
  • RNA / chemistry
  • RNA / genetics
  • Random Amplified Polymorphic DNA Technique
  • Sequence Alignment
  • Signal Transduction
  • Vibrio Infections / immunology*
  • Vibrio Infections / microbiology
  • Vibrio parahaemolyticus / immunology*


  • RNA
  • Interleukin-1 Receptor-Associated Kinases

Associated data

  • GENBANK/ADC53123