Institut Pasteur, Université de Paris Cité, CNRS UMR 3569, Viral populations and pathogenesis Unit, F-75015, Paris, France.
Institut de Recherche en Infectiologie de Montpellier (IRIM), , Université de Montpellier, CNRS, 34090, Montpellier, France.
Nat Commun. 2022 May 4;13(1):2442. doi: 10.1038/s41467-022-30134-9.
Interferon restricts SARS-CoV-2 replication in cell culture, but only a handful of Interferon Stimulated Genes with antiviral activity against SARS-CoV-2 have been identified. Here, we describe a functional CRISPR/Cas9 screen aiming at identifying SARS-CoV-2 restriction factors. We identify DAXX, a scaffold protein residing in PML nuclear bodies known to limit the replication of DNA viruses and retroviruses, as a potent inhibitor of SARS-CoV-2 and SARS-CoV replication in human cells. Basal expression of DAXX is sufficient to limit the replication of SARS-CoV-2, and DAXX over-expression further restricts infection. DAXX restricts an early, post-entry step of the SARS-CoV-2 life cycle. DAXX-mediated restriction of SARS-CoV-2 is independent of the SUMOylation pathway but dependent on its D/E domain, also necessary for its protein-folding activity. SARS-CoV-2 infection triggers the re-localization of DAXX to cytoplasmic sites and promotes its degradation. Mechanistically, this process is mediated by the viral papain-like protease (PLpro) and the proteasome. Together, these results demonstrate that DAXX restricts SARS-CoV-2, which in turn has evolved a mechanism to counteract its action.
干扰素可限制细胞培养中的 SARS-CoV-2 复制，但目前仅鉴定出少数具有抗 SARS-CoV-2 活性的干扰素刺激基因。在这里，我们描述了一个功能性的 CRISPR/Cas9 筛选，旨在鉴定 SARS-CoV-2 的限制因子。我们发现，DAXX 是一种支架蛋白，位于 PML 核小体中，已知其可限制 DNA 病毒和逆转录病毒的复制，是一种有效的 SARS-CoV-2 和 SARS-CoV 复制抑制剂。DAXX 的基础表达足以限制 SARS-CoV-2 的复制，而过表达 DAXX 则进一步限制感染。DAXX 限制了 SARS-CoV-2 生命周期的早期、进入后阶段。DAXX 介导的 SARS-CoV-2 限制不依赖于 SUMOylation 途径，但依赖于其 D/E 结构域，这也是其蛋白折叠活性所必需的。SARS-CoV-2 感染会触发 DAXX 向细胞质部位重新定位，并促进其降解。从机制上讲，这一过程由病毒的 papain-like 蛋白酶（PLpro）和蛋白酶体介导。综上所述，这些结果表明，DAXX 限制了 SARS-CoV-2，而 SARS-CoV-2 则进化出了一种对抗其作用的机制。
