Clathrin-Mediated Post-Golgi Membrane Trafficking in the Morphogenesis of Hepatitis Delta Virus
Clathrin-Mediated Post-Golgi Membrane Trafficking in the Morphogenesis of Hepatitis Delta Virus
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DOI：
10.1128/jvi.01044-09
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发表时间：
2009-12-01
影响因子：
5.4
通讯作者：
Chang, Ming-Fu
中科院分区：
文献类型：
--
作者：
Huang, Cheng;Chang, Shin C.;Chang, Ming-Fu
网格蛋白参与细胞蛋白的内吞和胞吐以及病毒感染的过程。我们之前已经证明了大型丁型肝炎抗原（HDAg-L）作为网格蛋白接头的功能，但网格蛋白参与丁型肝炎病毒（HDV）形态发生的详细机制尚不清楚。在这项研究中，我们发现网格蛋白重链（CHC）是HDV形态发生的关键决定因素。在网格蛋白盒上单氨基酸取代的HDAg-L保留了核输出活性，但不能与CHC相互作用并组装成病毒样颗粒。显性阴性突变体或短发夹RNA对CHC功能的下调会降低HDV组装的效率，但不会降低乙型肝炎病毒亚病毒颗粒的分泌。此外，从HDAg-L的C端衍生的细胞渗透性肽的共存显著干扰了HDAg-L的细胞内运输。发现HDAg-L、小HBsAg和CHC与反式高尔基网络共定位，并在网格蛋白包被的囊泡上高度富集。此外，基因II型HDV的组装效率低于基因I型HDV，其HDAg-L中可能有一个网格蛋白盒，但与CHC的相互作用很弱。各种HDV基因型的组装效率与其HDAg-Ls的chc结合活性密切相关，并与疾病结局的严重程度相吻合。因此，HDAg-L C末端的网格蛋白盒和核输出信号是HDV治疗潜在的新分子靶点。
Clathrin is involved in the endocytosis and exocytosis of cellular proteins and the process of virus infection. We have previously demonstrated that large hepatitis delta antigen (HDAg-L) functions as a clathrin adaptor, but the detailed mechanisms of clathrin involvement in the morphogenesis of hepatitis delta virus (HDV) are not clear. In this study, we found that clathrin heavy chain (CHC) is a key determinant in the morphogenesis of HDV. HDAg-L with a single amino acid substitution at the clathrin box retained nuclear export activity but failed to interact with CHC and to assemble into virus-like particles. Downregulation of CHC function by a dominant-negative mutant or by short hairpin RNA reduced the efficiency of HDV assembly, but not the secretion of hepatitis B virus subviral particles. In addition, the coexistence of a cell-permeable peptide derived from the C terminus of HDAg-L significantly interfered with the intracellular transport of HDAg-L. HDAg-L, small HBsAg, and CHC were found to colocalize with the trans-Golgi network and were highly enriched on clathrin-coated vesicles. Furthermore, genotype II HDV, which assembles less efficiently than genotype I HDV does, has a putative clathrin box in its HDAg-L but interacted only weakly with CHC. The assembly efficiency of the various HDV genotypes correlates well with the CHC-binding activity of their HDAg-Ls and coincides with the severity of disease outcome. Thus, the clathrin box and the nuclear export signal at the C terminus of HDAg-L are potential new molecular targets for HDV therapy.