Department of Pathology, The Johns Hopkins University, Baltimore, MD 21287, USA.
Virology. 2013 Oct;445(1-2):175-86. doi: 10.1016/j.virol.2013.04.017. Epub 2013 May 17.
The capsid protein L2 plays major roles in both papillomavirus assembly and the infectious process. While L1 forms the majority of the capsid and can self-assemble into empty virus-like particles (VLPs), L2 is a minor capsid component and lacks the capacity to form VLPs. However, L2 co-assembles with L1 into VLPs, enhancing their assembly. L2 also facilitates encapsidation of the ∼8 kbp circular and nucleosome-bound viral genome during assembly of the non-enveloped T=7d virions in the nucleus of terminally differentiated epithelial cells, although, like L1, L2 is not detectably expressed in infected basal cells. With respect to infection, L2 is not required for particles to bind to and enter cells. However L2 must be cleaved by furin for endosome escape. L2 then travels with the viral genome to the nucleus, wherein it accumulates at ND-10 domains. Here, we provide an overview of the biology of L2.
衣壳蛋白 L2 在乳头瘤病毒的组装和感染过程中都起着重要作用。虽然 L1 构成了大部分衣壳，并且可以自我组装成空的病毒样颗粒（VLPs），但 L2 是一种次要的衣壳成分，并且没有形成 VLPs 的能力。然而，L2 与 L1 共同组装成 VLPs，从而增强了它们的组装。L2 还促进了非包膜 T=7d 病毒粒子在终末分化的上皮细胞的核内组装过程中，对大约 8 kbp 环状和核小体结合的病毒基因组的包装，尽管与 L1 一样，L2 在感染的基底细胞中无法检测到表达。关于感染，L2 对于颗粒与细胞结合和进入细胞是不需要的。然而，L2 必须被弗林蛋白酶切割才能逃逸内体。然后，L2 与病毒基因组一起运送到细胞核，在那里它在 ND-10 结构域中积累。在这里，我们提供了 L2 生物学的概述。
