Identification and characterization of the interferon-γ-inducible lysosomal thiol reductase gene in Chinese soft-shelled turtle, Pelodiscus sinensis
Identification and characterization of the interferon-γ-inducible lysosomal thiol reductase gene in Chinese soft-shelled turtle, Pelodiscus sinensis
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DOI：
10.1016/j.dci.2018.08.019
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发表时间：
2019-01-01
影响因子：
2.9
通讯作者：
Liu, Yi
中科院分区：
文献类型：
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作者：
Fu, Jianping;Chen, Shannan;Liu, Yi
外源性抗原的二硫键的还原对于MHC-II类抗原加工和呈递途径至关重要，并且由干扰素-γ-诱导型溶酶体硫醇还原酶（GILT）催化。本研究从中华鳖（Pelodiscus sinensis，PsGILT）中克隆了一个爬行动物GILT基因。PsGILT的cDNA全长为1631个核苷酸（nt），其中5 '-非翻译区（UTR）为3个核苷酸（nt），3'-非翻译区（UTR）为860个核苷酸（nt），开放阅读框（ORF）为768个核苷酸（nt），编码255个氨基酸（aa）。已知GILT中的保守特征，如信号肽、CXXC基序、GILT特征序列、N-糖基化位点和保守的半胱氨酸等，均在PsGILT蛋白中发现。基因组分析表明，PsGILT基因保持了脊椎动物GILT基因的“7外显子6内含子”结构。PsGILT在所有检查的器官/组织中表达，主要在脾脏和血液中表达。在用LPS、PolyI：C和重组IFN-γ（rIFN-γ）诱导后，观察到PBL中PsIFN-γ和PsGILT的mRNA表达水平增加。我们还在体外测试了rGILT的还原酶活性，发现它可以将完整的人IgG还原成H链和L链。这些结果提示PsGILT可能与其他脊椎动物GILT一样在抵抗细菌和病毒感染中发挥重要作用。
The reduction of disulfide bonds of exogenous antigens is crucial to the MHC-II class antigen processing and presenting pathway and is catalysed by interferon-gamma-inducible lysosomal thiol reductase (GILT). In this study, a reptile GILT gene from Chinese soft-shelled turtle, Pelodiscus sinensis (PsGILT), was identified. The full-length cDNA of PsGILT is 1631 nucleotides (nt), including a 5'-untranslated region (UTR) of 3 nt, a 3'-UTR of 860 nt and an open reading frame (ORF) of 768 nt encoding 255 amino acids (aa). The conserved features in known GILTs, such as signal peptide, CXXC motif, GILT signature sequence, N-glycosylation site and conserved cysteines, were all found in the putative PsGILT protein. Genomic analysis revealed that PsGILT kept the "7 exons and 6 introns" structure of vertebrate GILT genes. PsGILT was expressed in all examined organs/tissues and was mainly expressed in spleen and blood. Increased mRNA expression levels of PsIFN-gamma and PsGILT in PBLs were observed after induction with LPS, PolyI:C and recombinant IFN-gamma (rIFN-gamma). We also tested the reductase activity of rGILT in vitro and found that it could reduce intact human IgG into H chains and L chains. These above results implied that PsGILT may play an important role in resisting bacterial and viral infections, like other vertebrate GILTs.