Liebowitz D, Kopan R, Fuchs E, Sample J, Kieff E
Mol Cell Biol. 1987 Jul;7(7):2299-308. doi: 10.1128/mcb.7.7.2299-2308.1987.
The Epstein-Barr virus (EBV) latent infection membrane protein (LMP) is likely to be an important mediator of EBV-induced cell proliferation, since it is one of the few proteins encoded by the virus in latent infection and since production of this protein in Rat-1 cells results in their conversion to a fully transformed phenotype. LMP was previously noted to localize to patches at the cell periphery. In this paper we examine the basis of LMP patching in EBV-infected, transformed lymphocytes. Our data indicate that LMP is associated with the cytoskeletal protein vimentin. Although LMP is fully soluble in isotonic Triton X-100 buffer, only 50% of it is extracted from cells in this solution. The rest remains bound to the cytoskeleton. LMP undergoes phosphorylation, and phosphorylated LMP is preferentially associated with the cytoskeleton. As judged by both immunofluorescence and immunoelectron microscopy, the vimentin network in EBV-transformed lymphocytes or EBV-infected Burkitt tumor lymphocytes is abnormal. Vimentin and LMP often colocalize in a single patch near the plasma membrane. In response to Colcemid treatment of EBV-infected cells, vimentin reorganizes into perinuclear rings, as it does in uninfected cells. LMP is associated with these perinuclear rings. Vimentin (or a vimentin-associated protein) may be a transducer of an LMP transmembrane effect in lymphoproliferation.
爱泼斯坦-巴尔病毒（EBV）潜伏感染膜蛋白（LMP）可能是EBV诱导细胞增殖的重要介质，因为它是病毒在潜伏感染时编码的少数蛋白质之一，而且在大鼠-1细胞中产生这种蛋白质会导致它们转变为完全转化的表型。LMP此前被发现定位于细胞周边的斑块处。在本文中，我们研究了EBV感染的转化淋巴细胞中LMP形成斑块的基础。我们的数据表明LMP与细胞骨架蛋白波形蛋白相关。尽管LMP在等渗的Triton X-100缓冲液中完全可溶，但在该溶液中只有50%的LMP能从细胞中被提取出来。其余部分仍与细胞骨架结合。LMP会发生磷酸化，磷酸化的LMP优先与细胞骨架结合。通过免疫荧光和免疫电子显微镜判断，EBV转化的淋巴细胞或EBV感染的伯基特肿瘤淋巴细胞中的波形蛋白网络是异常的。波形蛋白和LMP常常在质膜附近的单个斑块中共定位。在用秋水仙酰胺处理EBV感染的细胞后，波形蛋白会重新组织成核周环，就像在未感染的细胞中一样。LMP与这些核周环相关。波形蛋白（或与波形蛋白相关的蛋白质）可能是LMP在淋巴细胞增殖中跨膜效应的传导器。
