The papillomavirus minor capsid protein, L2, induces localization of the major capsid protein, L1, and the viral transcription/replication protein, E2, to PML oncogenic domains
The papillomavirus minor capsid protein, L2, induces localization of the major capsid protein, L1, and the viral transcription/replication protein, E2, to PML oncogenic domains
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DOI：
10.1128/jvi.72.1.142-150.1998
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发表时间：
1998-01-01
影响因子：
5.4
通讯作者：
Schiller, JT
中科院分区：
文献类型：
--
作者：
Day, PM;Roden, RBS;Schiller, JT
我们使用免疫荧光染色和共聚焦显微镜来检测结构性和非结构性牛乳头瘤病毒(BPV)蛋白在产生感染性病毒粒子的培养细胞中的亚细胞定位。当单独表达时，主要衣壳蛋白L1呈弥漫性核分布，而次要衣壳蛋白L2定位于原单核细胞白血病蛋白(PML)癌基因段(PODS)的核区。L1和L2的共表达诱导L1重新定位到豆荚中，导致L1和L2的共定位。L2的表达对维持基因组和病毒DNA合成所需的非结构蛋白E1和E2的分布的影响也被检测到。E1蛋白的定位不受L2表达的影响。然而，在表达L2的细胞中，抗E2染色的模式发生了显著的变化。与L1类似，E2从分散的核位置移位到豆荚中，并与L2共同定位。L2在没有其他病毒成分的情况下招募全长E2。L2以前被证明是传染性BPV发生所必需的。我们目前的结果通过将病毒粒子组分招募到一个不同的核域，为L2在病毒粒子组件的组织中发挥作用提供了证据。这种L2依赖的共定位可能作为一种机制来促进乳头瘤病毒的组装，要么通过增加病毒粒子成分的局部浓度，要么通过提供有效包装和组装所需的物理结构。这些数据还表明，非结构病毒蛋白E2在病毒粒子组装中发挥了作用，特别是通过它与病毒DNA中特定序列的高亲和力相互作用，将病毒基因组招募到组装位置。
We have used immunofluorescent staining and confocal microscopy to examine the subcellular localization of structural and nonstructural bovine papillomavirus (BPV) proteins in cultured cells that produce infectious virions. When expressed separately, L1, the major capsid protein, showed a diffuse nuclear distribution while L2, the minor capsid protein, was found to localize to punctate nuclear regions identified as promonocytic leukemia protein (PML) oncogenic domains (PODs). Coexpression of L1 and L2 induced a relocation of L1 into the PODs, leading to the colocalization of L1 and L2. The effect of L2 expression on the distribution of the nonstructural viral proteins E1 and E2, which are required for maintenance of the genome and viral DNA synthesis, was also examined. The localization of the E1 protein was unaffected by L2 expression. However, the pattern of anti-E2 staining was dramatically altered in L2-expressing cells. Similar to L1, E2 was shifted from a dispersed nuclear locality into the PODs and colocalized with L2. The recruitment of full-length E2 by L2 occurred in the absence of other viral components. L2 was shown previously to be essential for the generation of infectious BPV. Our present results provide evidence for a role for L2 in the organization of virion components by recruiting them to a distinct nuclear domain. This L2-dependent colocalization probably serves as a mechanism to promote the assembly of papillomaviruses either by increasing the local concentration of virion constituents or by providing the physical architecture necessary for efficient packaging and assembly. The data also suggest a role for a nonstructural viral protein, E2, in virion assembly, specifically the recruitment of the viral genome to the sites of assembly, through its high-affinity interaction with specific sequences in the viral DNA.