Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY 10065.
Oncode Institute, Division of Biochemistry, The Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands.
Proc Natl Acad Sci U S A. 2021 Jan 5;118(1). doi: 10.1073/pnas.2015794118. Epub 2020 Dec 21.
The journey from plasma membrane to nuclear pore is a critical step in the lifecycle of DNA viruses, many of which must successfully deposit their genomes into the nucleus for replication. Viral capsids navigate this vast distance through the coordinated hijacking of a number of cellular host factors, many of which remain unknown. We performed a gene-trap screen in haploid cells to identify host factors for adenovirus (AdV), a DNA virus that can cause severe respiratory illness in immune-compromised individuals. This work identified Mindbomb 1 (MIB1), an E3 ubiquitin ligase involved in neurodevelopment, as critical for AdV infectivity. In the absence of MIB1, we observed that viral capsids successfully traffic to the proximity of the nucleus but ultimately fail to deposit their genomes within. The capacity of MIB1 to promote AdV infection was dependent on its ubiquitination activity, suggesting that MIB1 may mediate proteasomal degradation of one or more negative regulators of AdV infection. Employing complementary proteomic approaches to characterize proteins proximal to MIB1 upon AdV infection and differentially ubiquitinated in the presence or absence of MIB1, we observed an intersection between MIB1 and ribonucleoproteins (RNPs) largely unexplored in mammalian cells. This work uncovers yet another way that viruses utilize host cell machinery for their own replication, highlighting a potential target for therapeutic interventions that counter AdV infection.
从质膜到核孔的运输是 DNA 病毒生命周期中的关键步骤，其中许多病毒必须成功地将其基因组沉积到细胞核中进行复制。病毒衣壳通过协调劫持许多细胞宿主因子来穿越这个巨大的距离，其中许多因子仍然未知。我们在单倍体细胞中进行了基因陷阱筛选，以鉴定腺病毒（AdV）的宿主因子，腺病毒是一种可导致免疫功能低下个体严重呼吸道疾病的 DNA 病毒。这项工作鉴定了 Mindbomb 1（MIB1），一种参与神经发育的 E3 泛素连接酶，对 AdV 感染力至关重要。在没有 MIB1 的情况下，我们观察到病毒衣壳成功地运送到细胞核附近，但最终未能将其基因组沉积在其中。MIB1 促进 AdV 感染的能力依赖于其泛素化活性，表明 MIB1 可能介导 AdV 感染的一个或多个负调控因子的蛋白酶体降解。通过互补的蛋白质组学方法来描述 AdV 感染时接近 MIB1 的蛋白质和在存在或不存在 MIB1 时差异泛素化的蛋白质，我们观察到 MIB1 和核糖核蛋白（RNP）之间的交叉，这在哺乳动物细胞中很大程度上尚未被探索。这项工作揭示了病毒利用宿主细胞机制进行自身复制的另一种方式，突出了针对对抗 AdV 感染的治疗干预的潜在目标。
