Thrombin cleavage of the hepatitis E virus polyprotein at multiple conserved locations is required for genome replication.
Thrombin cleavage of the hepatitis E virus polyprotein at multiple conserved locations is required for genome replication.
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DOI：
10.1371/journal.ppat.1011529
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发表时间：
2023-07
期刊：
影响因子：
6.7
通讯作者：
Herod, Morgan R.
中科院分区：
文献类型：
--
作者：
Pierce, Danielle M.;Buchanan, Frazer J. T.;Macrae, Fraser L.;Mills, Jake T.;Cox, Abigail;Abualsaoud, Khadijah M.;Ward, Joseph C.;Ariens, Robert A. S.;Harris, Mark;Stonehouse, Nicola J.;Herod, Morgan R.
正义RNA病毒的基因组编码介导病毒复制所必需的多聚蛋白。这些病毒多聚蛋白必须经过蛋白水解（也称为多聚蛋白加工）以产生功能蛋白单位。这种蛋白水解可以通过病毒编码的蛋白酶以及宿主细胞蛋白酶进行，并且通常被认为是调节病毒复制的关键步骤。戊型肝炎病毒（HEV）是急性病毒性肝炎的主要病因。正义RNA基因组被翻译以产生称为pORF 1的多蛋白，其对于病毒基因组复制是必需且足够的。然而，戊型肝炎病毒中多蛋白加工的机制仍有待确定。在这项研究中，我们的目的是了解这种多蛋白的加工及其在病毒复制中的作用，使用体外翻译实验和HEV亚基因组复制子的组合。我们的数据表明没有证据表明病毒编码的蛋白酶或自动蛋白水解活性，因为体外翻译主要产生未加工的病毒多聚蛋白前体。然而，多蛋白内的七个切割位点（由生物信息学分析表明）易受宿主细胞蛋白酶凝血酶的影响。使用两个亚基因组复制子系统，我们证明，这些网站的诱变防止复制，如药理学抑制丝氨酸蛋白酶，包括凝血酶。总的来说，我们的数据支持一个模型，其中HEV使用宿主蛋白酶来支持复制，并且可能已经进化为独立于病毒编码的蛋白酶进行多蛋白加工。正链RNA病毒产生多聚蛋白，这些多聚蛋白被控制病毒复制的蛋白酶切割。所有研究充分的正链病毒的多聚蛋白以高度受控的方式进行蛋白水解，以产生功能蛋白并调节从翻译到RNA复制的转变。病毒多蛋白的蛋白水解通常由病毒编码的蛋白酶进行，尽管一些病毒使用宿主细胞蛋白酶。在这份报告中，我们提供的证据表明，戊型肝炎病毒，一种医学上重要的人类病原体，不编码蛋白酶，不像其他病毒多聚蛋白，不能进行自催化处理。相反，我们提供的证据表明，多蛋白是容易被宿主细胞蛋白酶凝血酶的蛋白水解，这是必不可少的病毒复制。我们的数据与之前的正义病毒复制教条相矛盾，并提出了一个模型，其中这种病毒可能已经进化到使用宿主蛋白酶来控制病毒复制和嗜性。
The genomes of positive-sense RNA viruses encode polyproteins that are essential for mediating viral replication. These viral polyproteins must undergo proteolysis (also termed polyprotein processing) to generate functional protein units. This proteolysis can be performed by virally-encoded proteases as well as host cellular proteases, and is generally believed to be a key step in regulating viral replication. Hepatitis E virus (HEV) is a leading cause of acute viral hepatitis. The positive-sense RNA genome is translated to generate a polyprotein, termed pORF1, which is necessary and sufficient for viral genome replication. However, the mechanism of polyprotein processing in HEV remains to be determined. In this study, we aimed to understand processing of this polyprotein and its role in viral replication using a combination of in vitro translation experiments and HEV sub-genomic replicons. Our data suggest no evidence for a virally-encoded protease or auto-proteolytic activity, as in vitro translation predominantly generates unprocessed viral polyprotein precursors. However, seven cleavage sites within the polyprotein (suggested by bioinformatic analysis) are susceptible to the host cellular protease, thrombin. Using two sub-genomic replicon systems, we demonstrate that mutagenesis of these sites prevents replication, as does pharmacological inhibition of serine proteases including thrombin. Overall, our data supports a model where HEV uses host proteases to support replication and could have evolved to be independent of a virally-encoded protease for polyprotein processing. Positive-strand RNA viruses produce polyproteins that are cleaved by proteases that control viral replication. The polyproteins of all well studied positive-strand viruses undergo proteolysis in a highly controlled manner to generate functional proteins and regulate the transition from translation to RNA replication. Proteolysis of viral polyproteins is generally performed by virally-encoded proteases, although host cellular proteases are used by some viruses. In this report, we provide evidence that suggests that hepatitis E virus, a medically important human pathogen, does not encode a protease and unlike other viral polyproteins, cannot undergo auto-catalytic processing. Instead, we provide evidence that the polyprotein is susceptible to proteolysis by the host cell protease thrombin and that this is essential for viral replication. Our data contradict the previous dogma of positive-sense viral replication and suggests a model where this virus could have evolved to use a host protease to control viral replication and tropism.
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DOI：
10.1099/vir.0.045351-0
发表时间：
2012-11
期刊：
The Journal of general virology
影响因子：
--
作者：
Smith DB;Vanek J;Ramalingam S;Johannessen I;Templeton K;Simmonds P
通讯作者：
Simmonds P
影响因子：
--
作者：
Hwang, Seungmin;Alhatlani, Bader;Arias, Armando;Caddy, Sarah L;Christodoulou, Constantina;Cunha, Juliana Bragazza;Emmott, Ed;Gonzalez-Hernandez, Marta;Kolawole, Abimbola;Lu, Jia;Rippinger, Christine;Sorgeloos, Frederic;Thorne, Lucy;Vashist, Surender;Goodfellow, Ian;Wobus, Christiane E
通讯作者：
Wobus, Christiane E
DOI：
10.3390/v8100270
发表时间：
2016-10-03
期刊：
Viruses
影响因子：
--
作者：
Doceul V;Bagdassarian E;Demange A;Pavio N
通讯作者：
Pavio N
影响因子：
6.7
作者：
Herod MR;Gold S;Lasecka-Dykes L;Wright C;Ward JC;McLean TC;Forrest S;Jackson T;Tuthill TJ;Rowlands DJ;Stonehouse NJ
通讯作者：
Stonehouse NJ
影响因子：
3.9
作者：
Chinnaraj M;Planer W;Pozzi N
通讯作者：
Pozzi N