Khalil Mohamed I, Sommer Marvin H, Hay John, Ruyechan William T, Arvin Ann M
Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA, United States; Department of Molecular Biology, National Research Centre, El-Buhouth Street, Dokki, Cairo, Egypt.
Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA, United States.
Virology. 2015 Jul;481:179-86. doi: 10.1016/j.virol.2015.02.049. Epub 2015 Mar 17.
The VZV genome has two origins of DNA replication (oriS), each of which consists of an AT-rich sequence and three origin binding protein (OBP) sites called Box A, C and B. In these experiments, the mutation in the core sequence CGC of the Box A and C not only inhibited DNA replication but also inhibited both ORF62 and ORF63 expression in reporter gene assays. In contrast the Box B mutation did not influence DNA replication or flanking gene transcription. These results suggest that efficient DNA replication enhances ORF62 and ORF63 transcription. Recombinant viruses carrying these mutations in both sites and one with a deletion of the whole oriS were constructed. Surprisingly, the recombinant virus lacking both copies of oriS retained the capacity to replicate in melanoma and HELF cells suggesting that VZV has another origin of DNA replication.
水痘-带状疱疹病毒（VZV）基因组有两个DNA复制起点（oriS），每个复制起点都由富含AT的序列和三个称为A盒、C盒和B盒的起点结合蛋白（OBP）位点组成。在这些实验中，A盒和C盒核心序列CGC中的突变不仅抑制了DNA复制，还在报告基因检测中抑制了ORF62和ORF63的表达。相比之下，B盒突变不影响DNA复制或侧翼基因转录。这些结果表明高效的DNA复制可增强ORF62和ORF63的转录。构建了在两个位点都携带这些突变的重组病毒以及一个缺失整个oriS的重组病毒。令人惊讶的是，缺乏oriS两个拷贝的重组病毒仍保留在黑色素瘤细胞和人胚肺成纤维细胞（HELF）中复制的能力，这表明VZV还有另一个DNA复制起点。
