Structural basis for capsid recruitment and coat formation during HSV-1 nuclear egress
Structural basis for capsid recruitment and coat formation during HSV-1 nuclear egress
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DOI：
10.7554/elife.56627
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发表时间：
2020-06-24
期刊：
影响因子：
7.7
通讯作者：
Heldwein, Ekaterina E.
中科院分区：
文献类型：
--
作者：
Draganova, Elizabeth B.;Zhang, Jiayan;Heldwein, Ekaterina E.
在疱疹病毒感染过程中，新生病毒衣壳由病毒核输出复合体（NEC）介导从细胞核输出。NEC通过形成六边形阵列使衣壳周围的核膜（INM）变形。然而，NEC外壳如何与衣壳相互作用以及弯曲外壳如何产生以使出芽尚不清楚。在这里，通过结构引导截断，共聚焦显微镜和低温电子断层扫描，我们发现衣壳蛋白UL25的结合促进了NEC五边形而不是六边形的形成。我们假设在核出芽期间，位于五角形衣壳顶点的UL25与INM的NEC结合促进NEC五角形的形成，从而将NEC外壳固定在衣壳上。在与顶点接触的点上加入NEC五角形也会促进衣壳周围弯曲的六角形NEC涂层的组装，从而导致ul25修饰衣壳的有效出口。
During herpesvirus infection, egress of nascent viral capsids from the nucleus is mediated by the viral nuclear egress complex (NEC). NEC deforms the inner nuclear membrane (INM) around the capsid by forming a hexagonal array. However, how the NEC coat interacts with the capsid and how curved coats are generated to enable budding is yet unclear. Here, by structure-guided truncations, confocal microscopy, and cryoelectron tomography, we show that binding of the capsid protein UL25 promotes the formation of NEC pentagons rather than hexagons. We hypothesize that during nuclear budding, binding of UL25 situated at the pentagonal capsid vertices to the NEC at the INM promotes formation of NEC pentagons that would anchor the NEC coat to the capsid. Incorporation of NEC pentagons at the points of contact with the vertices would also promote assembly of the curved hexagonal NEC coat around the capsid, leading to productive egress of UL25-decorated capsids.