Reynolds G A, Goldstein J L, Brown M S
J Biol Chem. 1985 Aug 25;260(18):10369-77.
The current studies show that mRNAs with 16 different 5'-untranslated regions (varying in length from 68 to 670 nucleotides) are produced from the 3-hydroxy-3-methylglutaryl coenzyme A reductase gene in hamster UT-1 cells. This complex pattern of mRNAs results from a combination of multiple transcription initiation sites and multiple 5' splice donor sites for the intron in the 5'-untranslated region of the gene. Analysis of the multiple mRNAs was made possible by a modification of the S1 nuclease technique in which we used a series of progressively truncated uniformly labeled, single-stranded [32P]DNA probes in addition to the usual end-labeled 32P-probes. All of the reductase mRNAs are diminished when UT-1 cells are incubated with sterols, indicating that all of them are subject to coordinate control.
目前的研究表明，仓鼠UT-1细胞中3-羟基-3-甲基戊二酰辅酶A还原酶基因可产生16种不同5'-非翻译区（长度从68到670个核苷酸不等）的mRNA。这种复杂的mRNA模式是由该基因5'-非翻译区内多个转录起始位点和该内含子的多个5'剪接供体位点共同作用产生的。通过对S1核酸酶技术的改进，使得对多种mRNA的分析成为可能，在该改进技术中，除了常用的末端标记的32P探针外，我们还使用了一系列逐步截短的、均匀标记的单链[32P]DNA探针。当UT-1细胞与固醇一起孵育时，所有还原酶mRNA都会减少，这表明它们全部受到协同调控。
