RESUMO
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.
Assuntos
Expressão Gênica/genética , Fator 88 de Diferenciação Mieloide/genética , Stichopus/genética , Fator 6 Associado a Receptor de TNF/genética , Receptores Toll-Like/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular/métodos , DNA Complementar , Dados de Sequência Molecular , Fator 88 de Diferenciação Mieloide/metabolismo , Transdução de Sinais , Stichopus/metabolismo , Fator 6 Associado a Receptor de TNF/metabolismo , Receptores Toll-Like/metabolismoRESUMO
Selenium binding proteins (SeBPs) play a crucial role in controlling the oxidation/reduction in many physiological processes. Here we reported the isolation and characterization of a cDNA of SeBP gene from Sinonovacula constricta (denoted as ScSeBP). The full-length cDNA of ScSeBP was of 2345 bp, consisting of a 5'UTR of 246 bp, a 3' UTR of 626 bp, and a complete ORF of 1473 bp encoding a polypeptide with 491 amino acid residues. The predicted molecular mass of deduced amino acid of ScSeBP was 54.85 kDa and the theoretical pI was 6.44. Tissue distribution analysis of the ScSeBP revealed that the mRNA transcripts of ScSeBP were constitutively expressed in all examined tissues with the higher expressions in gill, gonad and the haemocytes. The temporal expression of ScSeBP in gill and haemocytes after B[α]P and heavy metals exposure were recorded by qPCR. B[α]P exposure at 0.5 and 5 mg L(-1) caused significant increase in mRNA expression of ScSeBP in haemocytes, but down-regulated ScSeBP mRNA expression in gill. Concerning heavy metals stresses, the suppressed expression patterns were detected in gill and haemocyte except lower concentration of PbCl2 exposure in haemocytes at 12 h. All our results indicated that ScSeBP was one of key effectors in mediating B[α]P and heavy metals exposure.