Lo S Y, Selby M J, Ou J H
Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles 90033, USA.
J Virol. 1996 Aug;70(8):5177-82. doi: 10.1128/JVI.70.8.5177-5182.1996.
Hepatitis C virus has three structural genes named C, E1, and E2. The C gene encodes the core (capsid) protein and the E1 and E2 genes encode the envelope proteins. In an immunoprecipitation experiment, the E1 protein was found to be precipitated by an anti-core antibody in the presence but not in the absence of the core protein, indicating that the E1 protein can interact with the core protein. This interaction is independent of whether the E1 and the C genes are linked in cis or separated in different DNA constructs for expression. The interaction between the core and the E1 proteins is confirmed by the observation that a hybrid protein derived from the core protein and the tissue plasminogen activator is localized in the nucleus in the absence of the E1 protein and in the perinuclear region in the presence of the E1 protein. Deletion-mapping studies indicate that the carboxy-terminal sequences of both the core and the E1 proteins are important for their interaction. Since little E1 sequence is exposed on the cytosolic side of the membrane of the endoplasmic reticulum, the interaction between the core and the E1 proteins most likely takes place in the endoplasmic reticulum membrane. The E2 protein could not be coprecipitated with the core protein by the anti-core antibody in a similar assay and likely does not interact with the core protein. The implications of these findings on the morphogenesis of the hepatitis C virus virion are discussed.
丙型肝炎病毒有三个结构基因，分别命名为C、E1和E2。C基因编码核心（衣壳）蛋白，E1和E2基因编码包膜蛋白。在一项免疫沉淀实验中，发现E1蛋白在有核心蛋白存在时能被抗核心抗体沉淀，而在无核心蛋白时则不能，这表明E1蛋白能与核心蛋白相互作用。这种相互作用与E1和C基因是顺式连接还是在不同的DNA构建体中分开表达无关。核心蛋白与E1蛋白之间的相互作用通过以下观察得到证实：一种由核心蛋白和组织型纤溶酶原激活剂衍生的杂合蛋白在无E1蛋白时定位于细胞核，在有E1蛋白时定位于核周区域。缺失图谱研究表明，核心蛋白和E1蛋白的羧基末端序列对它们的相互作用很重要。由于在内质网的膜的胞质侧几乎没有E1序列暴露，核心蛋白与E1蛋白之间的相互作用很可能发生在内质网膜上。在类似的实验中，E2蛋白不能被抗核心抗体与核心蛋白共沉淀，可能不与核心蛋白相互作用。本文讨论了这些发现对丙型肝炎病毒粒子形态发生的影响。
