The ESCRT system is required for hepatitis C virus production.
The ESCRT system is required for hepatitis C virus production.
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DOI：
10.1371/journal.pone.0014517
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发表时间：
2011-01-11
期刊：
影响因子：
3.7
通讯作者：
Kato N
中科院分区：
文献类型：
--
作者：
Ariumi Y;Kuroki M;Maki M;Ikeda M;Dansako H;Wakita T;Kato N
最近，脂滴已被发现参与一个重要的细胞器的丙型肝炎病毒（HCV）的生产。然而，HCV组装、出芽和释放的机制仍然知之甚少。逆转录病毒和一些其他包膜病毒需要转运所需的内体分选复合物（ESCRT）组分及其相关蛋白用于其出芽过程。为了确定HCV生产是否需要ESCRT系统，我们检查了HCV的感染性或培养上清液中的核心水平以及HuH-7衍生的RSc细胞中的HCV RNA水平，其中HCV-JFH 1可以感染并有效复制，表达靶向肿瘤易感基因101（TSG 101）、与肿瘤相关的基因2相互作用蛋白X（阿利克斯）、Vps 4 B、带电多泡体蛋白4 b（CHMP 4 b）或Brox，所有这些都是ESCRT系统的组分。我们发现，在这些敲减细胞中，上清液中HCV的感染性被显著抑制。因此，HCV-JFH 1感染后，在这些敲减细胞中，HCV核心向培养上清液中的释放被显著抑制，而HCV-JFH 1的细胞内感染性和RNA复制没有受到显著影响。此外，HCV核心主要与CHMP 4 b共定位，CHMP 4 b是ESCRT-III的一个组分。在这种情况下，HCV核心可以结合CHMP 4 b。然而，我们未能在HCV-JFH 1核心中找到与ESCRT组分相互作用所需的保守病毒晚期结构域基序，这表明HCV核心具有HCV产生所需的新基序。这些结果表明，ESCRT系统是感染性HCV产生所需的。
Recently, lipid droplets have been found to be involved in an important cytoplasmic organelle for hepatitis C virus (HCV) production. However, the mechanisms of HCV assembly, budding, and release remain poorly understood. Retroviruses and some other enveloped viruses require an endosomal sorting complex required for transport (ESCRT) components and their associated proteins for their budding process. To determine whether or not the ESCRT system is needed for HCV production, we examined the infectivity of HCV or the Core levels in culture supernatants as well as HCV RNA levels in HuH-7-derived RSc cells, in which HCV-JFH1 can infect and efficiently replicate, expressing short hairpin RNA or siRNA targeted to tumor susceptibility gene 101 (TSG101), apoptosis-linked gene 2 interacting protein X (Alix), Vps4B, charged multivesicular body protein 4b (CHMP4b), or Brox, all of which are components of the ESCRT system. We found that the infectivity of HCV in the supernatants was significantly suppressed in these knockdown cells. Consequently, the release of the HCV Core into the culture supernatants was significantly suppressed in these knockdown cells after HCV-JFH1 infection, while the intracellular infectivity and the RNA replication of HCV-JFH1 were not significantly affected. Furthermore, the HCV Core mostly colocalized with CHMP4b, a component of ESCRT-III. In this context, HCV Core could bind to CHMP4b. Nevertheless, we failed to find the conserved viral late domain motif, which is required for interaction with the ESCRT component, in the HCV-JFH1 Core, suggesting that HCV Core has a novel motif required for HCV production. These results suggest that the ESCRT system is required for infectious HCV production.