Okada Yuki, Suzuki Tadaki, Sunden Yuji, Orba Yasuko, Kose Shingo, Imamoto Naoko, Takahashi Hidehiro, Tanaka Shinya, Hall William W, Nagashima Kazuo, Sawa Hirofumi
Laboratory of Molecular and Cellular Pathology, Graduate School of Hokkaido University, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
EMBO Rep. 2005 May;6(5):452-7. doi: 10.1038/sj.embor.7400406.
The nuclear envelope is one of the chief obstacles to the translocation of macromolecules that are larger than the diameter of nuclear pores. Heterochromatin protein 1 (HP1) bound to the lamin B receptor (LBR) is thought to contribute to reassembly of the nuclear envelope after cell division. Human polyomavirus agnoprotein (Agno) has been shown to bind to HP1alpha and to induce its dissociation from LBR, resulting in destabilization of the nuclear envelope. Fluorescence recovery after photobleaching showed that Agno increased the lateral mobility of LBR in the inner nuclear membrane. Biochemical and immunofluorescence analyses showed that Agno is targeted to the nuclear envelope and facilitates the nuclear egress of polyomavirus-like particles. These results indicate that dissociation of HP1alpha from LBR and consequent perturbation of the nuclear envelope induced by polyomavirus Agno promote the translocation of virions out of the nucleus.
核膜是大于核孔直径的大分子易位的主要障碍之一。与核纤层蛋白B受体（LBR）结合的异染色质蛋白1（HP1）被认为有助于细胞分裂后核膜的重新组装。人多瘤病毒无义蛋白（Agno）已被证明可与HP1α结合并诱导其与LBR解离，从而导致核膜不稳定。光漂白后的荧光恢复显示，Agno增加了LBR在内核膜中的侧向流动性。生化和免疫荧光分析表明，Agno靶向核膜并促进多瘤病毒样颗粒的核输出。这些结果表明，多瘤病毒Agno诱导的HP1α与LBR解离以及随之而来的核膜扰动促进了病毒粒子从细胞核中易位。
