Bush M, Yager D R, Gao M, Weisshart K, Marcy A I, Coen D M, Knipe D M
Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115.
J Virol. 1991 Mar;65(3):1082-9. doi: 10.1128/JVI.65.3.1082-1089.1991.
We used indirect immunofluorescence to examine the factors determining the intranuclear location of herpes simplex virus (HSV) DNA polymerase (Pol) in infected cells. In the absence of viral DNA replication, HSV Pol colocalized with the HSV DNA-binding protein ICP8 in nuclear framework-associated structures called prereplicative sites. In the presence of viral DNA replication, HSV Pol colocalized with ICP8 in globular intranuclear structures called replication compartments. In cells infected with mutant viruses encoding defective ICP8 molecules, Pol localized within the cell nucleus but showed a general diffuse intranuclear distribution. In uninfected cells transfected with a plasmid expressing Pol, Pol similarly showed a diffuse intranuclear distribution. Therefore, Pol can localize to the cell nucleus without other viral proteins, but functional ICP8 is required for Pol to localize to prereplicative sites. In cells infected with mutant viruses encoding defective Pol molecules, ICP8 localized to prereplicative sites. Thus, Pol or the portions of Pol not expressed by the mutant viruses are not essential for the formation of prereplicative sites or the localization of ICP8 to these structures. These results demonstrate that a specific nuclear protein can influence the intranuclear location of another nuclear protein.
我们使用间接免疫荧光法来检测决定单纯疱疹病毒（HSV）DNA聚合酶（Pol）在受感染细胞内核定位的因素。在没有病毒DNA复制的情况下，HSV Pol与HSV DNA结合蛋白ICP8在称为复制前位点的核骨架相关结构中共定位。在有病毒DNA复制的情况下，HSV Pol与ICP8在称为复制区室的球状核内结构中共定位。在感染了编码缺陷ICP8分子的突变病毒的细胞中，Pol定位于细胞核内，但呈现出普遍的核内弥散分布。在用表达Pol的质粒转染的未感染细胞中，Pol同样呈现出核内弥散分布。因此，Pol可以在没有其他病毒蛋白的情况下定位于细胞核，但功能性的ICP8是Pol定位于复制前位点所必需的。在感染了编码缺陷Pol分子的突变病毒的细胞中，ICP8定位于复制前位点。因此，Pol或突变病毒未表达的Pol部分对于复制前位点的形成或ICP8定位于这些结构并非必需。这些结果表明，一种特定的核蛋白可以影响另一种核蛋白的核内定位。
