Rösch Kathrin, Kwiatkowski Marcel, Hofmann Sarah, Schöbel Anja, Grüttner Cordula, Wurlitzer Marcus, Schlüter Hartmut, Herker Eva
Heinrich Pette Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany.
Core Facility Mass Spectrometric Proteomics, Institute of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
Cell Rep. 2016 Sep 20;16(12):3219-3231. doi: 10.1016/j.celrep.2016.08.052.
Lipid droplets are vital to hepatitis C virus (HCV) infection as the putative sites of virion assembly, but morphogenesis and egress of virions remain ill defined. We performed quantitative lipid droplet proteome analysis of HCV-infected cells to identify co-factors of that process. Our results demonstrate that HCV disconnects lipid droplets from their metabolic function. Annexin A3 (ANXA3), a protein enriched in lipid droplet fractions, strongly impacted HCV replication and was characterized further: ANXA3 is recruited to lipid-rich fractions in HCV-infected cells by the viral core and NS5A proteins. ANXA3 knockdown does not affect HCV RNA replication but severely impairs virion production with lower specific infectivity and higher density of secreted virions. ANXA3 is essential for the interaction of viral envelope E2 with apolipoprotein E (ApoE) and for trafficking, but not lipidation, of ApoE in HCV-infected cells. Thus, we identified ANXA3 as a regulator of HCV maturation and egress.
脂滴对于丙型肝炎病毒（HCV）感染至关重要，被认为是病毒粒子组装的场所，但病毒粒子的形态发生和释放仍不清楚。我们对HCV感染的细胞进行了定量脂滴蛋白质组分析，以确定该过程的辅助因子。我们的结果表明，HCV使脂滴与其代谢功能分离。膜联蛋白A3（ANXA3）是一种在脂滴组分中富集的蛋白质，对HCV复制有强烈影响，并进一步进行了表征：ANXA3被病毒核心蛋白和NS5A蛋白招募到HCV感染细胞中富含脂质的组分中。敲低ANXA3并不影响HCV RNA复制，但会严重损害病毒粒子的产生，导致分泌的病毒粒子具有较低的特异性感染力和较高的密度。ANXA3对于病毒包膜E2与载脂蛋白E（ApoE）的相互作用以及HCV感染细胞中ApoE的运输（而非脂化）至关重要。因此，我们确定ANXA3是HCV成熟和释放的调节因子。
