title: Two adaptor molecules of MyD88 and TRAF6 in Apostichopus japonicus Toll signaling cascade: molecular cloning and expression analysis.
abstract: Myeloid differentiation factor 88 (MyD88) and tumor necrosis factor receptor-associated factor 6 (TRAF6) are two key adaptor molecules in Toll-like receptor signal transduction that triggers downstream cascades involved in innate immunity. Here we reported the isolation and characterization the full-length cDNAs of MyD88 and TRAF6 from sea cucumber Apostichopus japonicus (denoted as AjMyD88 and AjTRAF6, respectively). Both of two factors shared a remarkable high degree of structural conservation with their mammalian and Drosophila orthologs, such as a typical death domain (DD) and a conservative Toll/IL-1R (TIR) domain for the deduced amino acid of AjMyD88, a zinc finger of RING-type, two zinc fingers of TRAF-type, a coiled-coil region, and a MATH domain for that of AjTRAF6. Constitutive expression patterns were also observed in the two genes with different expression levels. AjMyD88 mRNA transcripts were higher expressed in intestine and respiratory trees, and AjTRAF6 were abundant in coelomocytes and tentacle. During Vibrio splendidus challenge experiment, the expression levels of two genes were increased significantly with larger amplitude and longer duration in AjTRAF6. The peak expression levels were detected at 6 h for AjMyD88 with 1.80-fold increase, and at 24 h for AjTRAF6 with 2.73-fold increase compared with that in the control group. All these results suggested that AjMyD88 and AjTRAF6 might be involved into immune response toward V. splendidus challenge.
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo, Zhejiang Province 315211, PR China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Lu
authors.forename: Chenghua
authors.initials: C
authors.lastname: Li
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Yina
authors.initials: Y
authors.lastname: Shao
authors.forename: Xiurong
authors.initials: X
authors.lastname: Su
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
authors.forename: Taiwu
authors.initials: T
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular / Q000379:methods; D018076:DNA, Complementary; D015870:Gene Expression / Q000235:genetics*; D008969:Molecular Sequence Data; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D047528:Stichopus / Q000235:genetics* / Q000378:metabolism; D048029:TNF Receptor-Associated Factor 6 / Q000235:genetics* / Q000378:metabolism; D051193:Toll-Like Receptors / Q000235:genetics* / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D053594:Myeloid Differentiation Factor 88; D048029:TNF Receptor-Associated Factor 6; D051193:Toll-Like Receptors
keywords: Apostichopus japonicus; Immune response; Myeloid differentiation factor 88; Tumor necrosis factor receptor-associated factor 6; Vibrio splendidus