Setzer D R, McGrogan M, Schimke R T
J Biol Chem. 1982 May 10;257(9):5143-7.
We have previously reported the presence of four dihydrofolate reductase messenger RNAs differing in the length of 3' untranslated regions in murine cells (Setzer, D. R., McGrogan, M., Nunberg, J. H., and Schimke, R. T. (1980) Cell 22, 361-370). We have now mapped the 3' ends of these RNAs more precisely and have demonstrated colinearity between their shared sequences. Analysis of three larger dihydrofolate reductase RNAs has shown that these RNA species contain very long 3' noncoding regions, bringing the total number of dihydrofolate reductase RNAs to seven, ranging in length from 750 to 5600 nucleotides. We have determined the nucleotide sequence at and surrounding the polyadenylation sites of the four smaller RNAs. We find no striking structures in this sequence that might constitute multiple polyadenylation signals, but conclude that the putative polyadenylation signal AAUAAA is not required for polyadenylation of at least three of the four dihydrofolate reductase messengers.
我们之前报道过，在鼠细胞中存在四种二氢叶酸还原酶信使核糖核酸，其3'非翻译区的长度不同（塞策尔，D. R.，麦格罗根，M.，农伯格，J. H.，以及施姆克，R. T.（1980年）《细胞》22卷，361 - 370页）。我们现在更精确地绘制了这些核糖核酸的3'末端图谱，并证明了它们共享序列之间的共线性。对三种更大的二氢叶酸还原酶核糖核酸的分析表明，这些核糖核酸种类包含非常长的3'非编码区，使得二氢叶酸还原酶核糖核酸的总数达到七种，长度从750到5600个核苷酸不等。我们已经确定了四种较小核糖核酸的聚腺苷酸化位点及其周围的核苷酸序列。我们在该序列中未发现可能构成多个聚腺苷酸化信号的显著结构，但得出结论，对于四种二氢叶酸还原酶信使核糖核酸中的至少三种，推定的聚腺苷酸化信号AAUAAA并非聚腺苷酸化所必需。
