Involvement of ESCRT-II in hepatitis B virus morphogenesis.
Involvement of ESCRT-II in hepatitis B virus morphogenesis.
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DOI：
10.1371/journal.pone.0091279
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Prange R
中科院分区：
文献类型：
--
作者：
Stieler JT;Prange R
乙型肝炎病毒（HBV）是一种包膜DNA病毒，通过其基因组前RNA （pgRNA）的逆转录进行复制。HBV的出芽应该发生在细胞膜内，并且需要ESCRT- iii和VPS4提供的运输所需的内体分选复合物（ESCRT）的切割功能。在这里，我们研究了上游作用的ESCRT-I和ESCRT-II复合物对HBV形态发生的影响。RNA干扰敲低ESCRT-I亚基TSG101和VPS28不会阻断病毒释放，反而会刺激病毒释放。相比之下，rnai介导的ESCRT-II组分EAP20、EAP30和EAP45的缺失大大减少了病毒的输出。通过分析HBV成熟途径的不同步骤，我们发现敲低ESCRT-II不仅抑制了包膜病毒粒子的产生和/或释放，而且还破坏了细胞内核衣壳的形成。转录/翻译研究表明，ESCRT-II的缺失既不影响hbv特异性rna的合成和核输出，也不影响病毒核心和包膜蛋白的表达。此外，ESCRT-II的缺失对HBV核心/衣壳的组装能力和完整性没有影响。然而，在ESCRT-II缺失的细胞中，封装的pgRNA水平显著降低，这意味着ESCRT-II指导了伴随复制能力核衣壳形成的步骤，例如协助RNA运输和封装。为了支持这一点，衣壳蛋白被发现在病毒产生细胞中与ESCRT-II亚基相互作用和共定位。总之，这些结果表明ESCRT-II在HBV生命周期中起重要作用，并表明ESCRT-II在最终HBV出芽反应之前起作用。
The hepatitis B virus (HBV) is an enveloped DNA virus that replicates via reverse transcription of its pregenomic RNA (pgRNA). Budding of HBV is supposed to occur at intracellular membranes and requires scission functions of the endosomal sorting complex required for transport (ESCRT) provided by ESCRT-III and VPS4. Here, we have investigated the impact of the upstream-acting ESCRT-I and ESCRT-II complexes in HBV morphogenesis. RNA interference knockdown of the ESCRT-I subunits TSG101 and VPS28 did not block, but rather stimulate virus release. In contrast, RNAi-mediated depletion of the ESCRT-II components EAP20, EAP30 and EAP45 greatly reduced virus egress. By analyzing different steps of the HBV maturation pathway, we find that the knockdown of ESCRT-II not only inhibited the production and/or release of enveloped virions, but also impaired intracellular nucleocapsid formation. Transcription/translation studies revealed that the depletion of ESCRT-II neither affected the synthesis and nuclear export of HBV-specific RNAs nor the expression of the viral core and envelope proteins. Moreover, the absence of ESCRT-II had no effects on the assembly capability and integrity of HBV core/capsids. However, the level of encapsidated pgRNA was significantly reduced in ESCRT-II-depleted cells, implicating that ESCRT-II directs steps accompanying the formation of replication-competent nucleocapsids, like e.g. assisting in RNA trafficking and encapsidation. In support of this, the capsid protein was found to interact and colocalize with ESCRT-II subunits in virus-producing cells. Together, these results indicate an essential role for ESCRT-II in the HBV life cycle and suggest that ESCRT-II functions prior to the final HBV budding reaction.
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DOI：
10.1038/nrm2937
发表时间：
2010-08
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
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影响因子：
5.4
作者：
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通讯作者：
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作者：
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通讯作者：
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影响因子：
4.8
作者：
Bowers, K;Piper, SC;Luzio, JP
通讯作者：
Luzio, JP
DOI：
10.1073/pnas.1211759109
发表时间：
2012-10-16
影响因子：
11.1
作者：
Carlson, Lars-Anders;Hurley, James H.
通讯作者：
Hurley, James H.