McGeady M L, Wood T G, Maizel J V, Vande Woude G F
DNA. 1986 Aug;5(4):289-98. doi: 10.1089/dna.1986.5.289.
A region upstream from the mouse c-mos proto-oncogene, termed upstream mouse sequence (UMS), prevents expression of mos transforming activity. Previous studies suggested that the UMS prevented transcription readthrough. In this study, we constructed a recombinant DNA clone, pHTS3MS, with the UMS inserted downstream from both the mos gene and a truncated long terminal repeat containing only the U3 enhancer region. In this position UMS did not inhibit mos transforming activity. We examined cells transformed by pHTS3MS for RNA expression. S1 nuclease analysis showed that the UMS provides two polyadenylation signals to mos-containing RNA and nuclear run-on transcription showed that the primary transcripts terminate in UMS. In addition, using portions of the UMS, we found that a 360-bp fragment containing the UMS polyadenylation signals and sites inserted between the herpes simplex virus type 1 (HSV-1) thymidine kinase gene (tk) and its promoter inhibits tk transforming activity by 99% and prevents detectable expression of this construct in transient expression assays. Thus, the UMS must contain signals for polyadenylation and appears to function as a transcription terminator.
小鼠c-mos原癌基因上游的一个区域，称为上游小鼠序列（UMS），可阻止mos转化活性的表达。先前的研究表明，UMS可阻止转录通读。在本研究中，我们构建了一个重组DNA克隆pHTS3MS，其中UMS插入到mos基因和仅包含U3增强子区域的截短长末端重复序列的下游。在这个位置，UMS并不抑制mos转化活性。我们检测了由pHTS3MS转化的细胞的RNA表达。S1核酸酶分析表明，UMS为含mos的RNA提供了两个聚腺苷酸化信号，细胞核连续转录分析表明初级转录本在UMS处终止。此外，使用UMS的部分片段，我们发现一个包含UMS聚腺苷酸化信号和位点的360 bp片段插入单纯疱疹病毒1型（HSV-1）胸苷激酶基因（tk）及其启动子之间，可将tk转化活性抑制99%，并在瞬时表达试验中阻止该构建体的可检测表达。因此，UMS必须包含聚腺苷酸化信号，并且似乎起到转录终止子的作用。
