Interferons (IFNs) induce the expression of interferon-stimulated genes (ISGs), many of which are responsible for the cellular antiviral state in which the replication of numerous viruses is blocked. How the majority of individual ISGs inhibit the replication of particular viruses is unknown. We conducted a loss-of-function screen to identify genes required for the activity of alpha interferon (IFN-α) against vesicular stomatitis virus, Indiana serotype (VSVIND), a prototype negative-strand RNA virus. Our screen revealed that TRIM69, a member of the tripartite motif (TRIM) family of proteins, is a VSVIND inhibitor. TRIM69 potently inhibited VSVIND replication through a previously undescribed transcriptional inhibition mechanism. Specifically, TRIM69 physically associates with the VSVIND phosphoprotein (P), requiring a specific peptide target sequence encoded therein. P is a cofactor for the viral polymerase and is required for viral RNA synthesis, as well as the assembly of replication compartments. By targeting P, TRIM69 inhibits pioneer transcription of the incoming virion-associated minus-strand RNA, thereby preventing the synthesis of viral mRNAs, and consequently impedes all downstream events in the VSVIND replication cycle. Unlike some TRIM proteins, TRIM69 does not inhibit viral replication by inducing degradation of target viral proteins. Rather, higher-order TRIM69 multimerization is required for its antiviral activity, suggesting that TRIM69 functions by sequestration or anatomical disruption of the viral machinery required for VSVIND RNA synthesis.IMPORTANCE Interferons are important antiviral cytokines that work by inducing hundreds of host genes whose products inhibit the replication of many viruses. While the antiviral activity of interferon has long been known, the identities and mechanisms of action of most interferon-induced antiviral proteins remain to be discovered. We identified gene products that are important for the antiviral activity of interferon against vesicular stomatitis virus (VSV), a model virus that whose genome consists of a single RNA molecule with negative-sense polarity. We found that a particular antiviral protein, TRIM69, functions by a previously undescribed molecular mechanism. Specifically, TRIM69 interacts with and inhibits the function of a particular phosphoprotein (P) component of the viral transcription machinery, preventing the synthesis of viral messenger RNAs.

中文翻译：

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在干扰素诱导的抗病毒状态下，TRIM69 会抑制水泡性口炎病毒转录。


干扰素 (IFN) 诱导干扰素刺激基因 (ISG) 的表达，其中许多基因负责细胞抗病毒状态，在这种状态下，许多病毒的复制被阻止。大多数单独的 ISG 如何抑制特定病毒的复制尚不清楚。我们进行了功能丧失筛选，以确定α干扰素 (IFN-α) 对抗水泡性口炎病毒印第安纳血清型 (VSVIND)（一种原型负链 RNA 病毒）活性所需的基因。我们的筛选显示 TRIM69 是蛋白质三联基序 (TRIM) 家族的成员，是一种 VSVIND 抑制剂。 TRIM69 通过先前未描述的转录抑制机制有效抑制 VSVIND 复制。具体而言，TRIM69 与 VSVIND 磷蛋白 (P) 物理结合，需要其中编码的特定肽靶序列。 P 是病毒聚合酶的辅助因子，是病毒 RNA 合成以及复制区室组装所必需的。通过靶向 P，TRIM69 抑制传入病毒粒子相关负链 RNA 的先驱转录，从而阻止病毒 mRNA 的合成，从而阻止 VSVIND 复制周期中的所有下游事件。与某些 TRIM 蛋白不同，TRIM69 不会通过诱导目标病毒蛋白降解来抑制病毒复制。相反，TRIM69 的抗病毒活性需要更高阶的多聚化，这表明 TRIM69 通过隔离或解剖破坏 VSVIND RNA 合成所需的病毒机制来发挥作用。 重要性 干扰素是重要的抗病毒细胞因子，通过诱导数百个宿主基因发挥作用，这些基因的产物抑制许多病毒的复制。 虽然干扰素的抗病毒活性早已为人所知，但大多数干扰素诱导的抗病毒蛋白的特性和作用机制仍有待发现。我们鉴定了对干扰素针对水疱性口炎病毒（VSV）的抗病毒活性非常重要的基因产物，VSV是一种模型病毒，其基因组由具有负义极性的单个RNA分子组成。我们发现一种特殊的抗病毒蛋白 TRIM69 通过以前未描述的分子机制发挥作用。具体来说，TRIM69 与病毒转录机制的特定磷蛋白 (P) 成分相互作用并抑制其功能，从而阻止病毒信使 RNA 的合成。