Khalili K, Feigenbaum L, Khoury G
Virology. 1987 Jun;158(2):469-72. doi: 10.1016/0042-6822(87)90224-8.
We have used primer extension and S1 analysis to localize the 5'-termini of JC virus (JCV) early RNAs in infected primary human fetal glial cells at various times postinfection and in stable JCV-transformed hamster fetal glial cells. At early times postinfection (Days 1-5), two early transcripts are initiated at nucleotides 5122 and 5082. A major shift in 5'-ends at later times results in the synthesis of a new series of early mRNAs beginning upstream at nucleotide 35 and downstream at nucleotides 5047, 5037, and 5012. In the transformed hamster cells, however, only one RNA species was detected, starting at nucleotide 5122. The mechanism underlying the shift in the initiation site of JCV early RNAs during a lytic infection remains unclear but appears analogous to that which occurs in the SV40 lytic cycle. Since the shift occurs during DNA replication, when T-antigen is at maximal levels, it is possible that T-antigen binding to JCV DNA and/or alterations in chromatin structure contribute to this event.
我们运用引物延伸和S1分析技术，在感染后的不同时间点，对感染原发性人胎儿神经胶质细胞以及稳定的JC病毒转化的仓鼠胎儿神经胶质细胞中JC病毒（JCV）早期RNA的5'-末端进行定位。在感染后的早期（第1 - 5天），两个早期转录本起始于核苷酸5122和5082。后期5'-末端的主要转变导致了一系列新的早期mRNA的合成，这些mRNA起始于上游的核苷酸35以及下游的核苷酸5047、5037和5012。然而，在转化的仓鼠细胞中，仅检测到一种RNA，起始于核苷酸5122。JCV早期RNA在裂解感染期间起始位点转变的潜在机制仍不清楚，但似乎类似于SV40裂解周期中发生的情况。由于这种转变发生在DNA复制期间，此时T抗原处于最高水平，因此T抗原与JCV DNA的结合和/或染色质结构的改变可能促成了这一事件。
