Sato K, Ito R, Baek K H, Agarwal K
Mol Cell Biol. 1986 Apr;6(4):1032-43. doi: 10.1128/mcb.6.4.1032-1043.1986.
We located and characterized a downstream transcriptional regulatory element in the human gastrin gene by transferring the gastrin gene 3' fragment, from which the polyadenylation signal sequence was deleted, into the shuttle vector pSCAT10 at a site located immediately downstream from the chloramphenicol acetyltransferase (CAT) gene and upstream from the simian virus 40 polyadenylation region. Study of CAT RNA derived from the hybrid plasmids, indicated regulation of transcription on the gastrin gene fragment. Analysis of deletion mutants generated from the 5' region of the fragment by CAT assay and by S1 nuclease mapping of mRNAs indicated the possible involvement of an oligothymidylate-rich sequence in transcription regulation. Mapping of gastrin gene RNA 3' ends to the 5' side proximal to the oligothymidylate-rich sequence clearly demonstrated that this sequence is a transcriptional terminator element. This unique sequence, interspersed with one or two adenines, which also functions in an orientation-dependent manner, is located 192 nucleotides downstream from the gastrin gene polyadenylation site, and serves as a transcriptional termination signal.
我们通过将人胃泌素基因3′端片段（其中的聚腺苷酸化信号序列已被删除）插入穿梭载体pSCAT10中氯霉素乙酰转移酶（CAT）基因紧邻下游且猿猴病毒40聚腺苷酸化区域上游的位点，定位并鉴定了人胃泌素基因中的一个下游转录调控元件。对源自杂交质粒的CAT RNA的研究表明，胃泌素基因片段上存在转录调控。通过CAT分析和mRNA的S1核酸酶图谱分析对该片段5′端区域产生的缺失突变体进行研究，表明富含寡聚胸苷酸的序列可能参与转录调控。胃泌素基因RNA 3′端在富含寡聚胸苷酸序列近端的5′侧的定位清楚地表明，该序列是一个转录终止元件。这个独特的序列，穿插有一两个腺嘌呤，也以方向依赖的方式发挥作用，位于胃泌素基因聚腺苷酸化位点下游192个核苷酸处，作为转录终止信号。
