Abstract：
The viral nuclear egress complex (NEC) allows herpesvirus capsids to escape from the nucleus without compromising the nuclear envelope integrity. The NEC lattice assembles on the inner nuclear membrane and mediates the budding of nascent nucleocapsids into the perinuclear space and their subsequent release into the cytosol. Its essential role makes it a potent antiviral target, necessitating structural information in the context of a cellular infection. Here we determined structures of NEC-capsid interfaces in situ using electron cryo-tomography, showing a substantial structural heterogeneity. In addition, while the capsid is associated with budding initiation, it is not required for curvature formation. By determining the NEC structure in several conformations, we show that curvature arises from an asymmetric assembly of disordered and hexagonally ordered lattice domains independent of pUL25 or other viral capsid vertex components. Our results advance our understanding of the mechanism of nuclear egress in the context of a living cell.
摘要：
病毒核出口复合物(NEC)允许疱疹病毒衣壳从核逃逸而不损害核包膜完整性。NEC晶格聚集在内核膜上，并介导新生核衣壳的出芽进入核周空间，并随后释放到细胞质中。它的重要作用使其成为有效的抗病毒靶标，在细胞感染的背景下需要结构信息。在这里，我们使用电子冷冻层析成像技术原位确定了NEC-衣壳界面的结构，显示出实质性的结构异质性。此外,虽然衣壳与萌芽有关，曲率形成不需要。通过确定几种构象中的NEC结构，我们表明，曲率来自无序和六边形有序晶格域的不对称组装，而与pUL25或其他病毒衣壳顶点组件无关。我们的结果增进了我们对活细胞背景下核外出机制的理解。
