Kenney S, Natarajan V, Selzer G, Salzman N P
J Virol. 1986 May;58(2):651-4. doi: 10.1128/JVI.58.2.651-654.1986.
Within its enhancer promoter region, the MAD-1 strain of JC virus (JCV) has two 98-base-pair tandem repeats, each containing a TATA box-like sequence. In the present study, polyadenylated early JCV mRNAs were isolated 5 or 29 days after infection of primary human fetal glial (PHFG) cells. By using S1 nuclease, the 5' termini of the early mRNAs were mapped to nucleotide position(s) (np) 122 through 125, which lies within an AT rich region (at np 113 through 127). In contrast, when JCV DNA was transcribed in vitro, we observed a single major cluster of 5' start sites at np 94 through 97, which is approximately 25 base pairs downstream from one of the TATA boxes. By day 5, the earliest time at which JCV RNA was detected, viral DNA replication had begun; it continued for at least an additional 20 days. Since more late than early RNA was present at 5 days postinfection, the early RNAs whose synthesis began at np 122 through 125 may be analogous to SV40 late early mRNA (Ghosh and Lebowitz, J. Virol. 40:224-240, 1981). However, we have not detected RNAs with 5' termini 25 to 30 bp downstream from the TATA box at earlier times. While JCV contains two identical TATA boxes, one in each of the 98-bp repeats, only the upstream TATA box functions as an early promoter element.
在其增强子启动子区域，JC病毒（JCV）的MAD - 1株有两个98个碱基对的串联重复序列，每个重复序列都包含一个类似TATA框的序列。在本研究中，在原代人胎儿神经胶质（PHFG）细胞感染后5天或29天分离出多聚腺苷酸化的早期JCV mRNA。通过使用S1核酸酶，早期mRNA的5'末端被定位到核苷酸位置（np）122至125，该位置位于富含AT的区域（np 113至127）内。相比之下，当JCV DNA在体外转录时，我们观察到一个主要的5'起始位点簇位于np 94至97，这大约在其中一个TATA框下游25个碱基对处。到第5天，即最早检测到JCV RNA的时间，病毒DNA复制已经开始；它至少持续了另外20天。由于在感染后5天存在的晚期RNA比早期RNA多，其合成起始于np 122至125的早期RNA可能类似于SV40晚期早期mRNA（戈什和莱博维茨，《病毒学杂志》40:224 - 240，1981）。然而，我们在更早的时间没有检测到5'末端在TATA框下游25至30 bp处的RNA。虽然JCV包含两个相同的TATA框，每个98 bp重复序列中各有一个，但只有上游的TATA框作为早期启动子元件起作用。
