SIGNAL SEQUENCE FOR GENERATION OF MESSENGER-RNA 3' END IN THE SACCHAROMYCES-CEREVISIAE GAL7 GENE
SIGNAL SEQUENCE FOR GENERATION OF MESSENGER-RNA 3' END IN THE SACCHAROMYCES-CEREVISIAE GAL7 GENE
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DOI：
10.1002/j.1460-2075.1990.tb07581.x
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发表时间：
1990-11-01
期刊：
影响因子：
11.4
通讯作者：
FUKASAWA, T
中科院分区：
文献类型：
--
作者：
ABE, A;HIRAOKA, Y;FUKASAWA, T
我们已经确定了一个信号序列(指定为核心信号)，以确定酿酒酵母GAL7基因3‘端在26个碱基对的DNA片段中的形成。该序列位于GAL7基因3‘端的上游4-5个核苷酸，即多聚腺苷酸化位点。用pBR322 DNA替换包含多聚腺苷化位点的DNA片段，保持核心信号不变，导致mRNA3‘’端发生几个核苷酸的改变，这表明在多聚腺苷化位点或其附近存在额外的信号(指定的末端信号)。当核心信号被放置在相反方向时，正常末端形成被取消。用SP6 RNA聚合酶在含有这些信号的DNA片段的模板上体外合成的相当一部分Pre-mRNA在无细胞的酵母体系中孵育过程中，可能在体外3‘’端被切割和多腺化。相比之下，在仅有核心信号的模板上合成的premRNA得到了处理，但效率要低得多。当前信使核糖核酸缺乏核心信号或以相反的方向含有核心信号时，则不能看到这种处理。
We have identified a signal sequence (designated core signal) necessary to specify formation of mRNA 3'' end of the GAL7 genes in Saccharomyces cerevisiae within a DNA segment 26 bp long. The sequence was located 4-5 nucleotides upstream from the 3'' end, i.e. the polyadenylation site, of the GAL7 mRNA. Replacement of a DNA segment encompassing the polyadenylation site with a pBR322 DNA, leaving the core signal intact, resulted in alteration of the mRNA 3'' end by several nucleotides, suggesting the existence of an additional signal (designated end signal) at or near the polyadenylation site. The normal end formation was abolished when the core signal was placed in the reverse orientation. A considerable fraction of pre-mRNA synthesized in vitro with SP6 RNA polymerase on the template of a DNA fragment containing these signals was cleaved and polyadenylated presumably at the in vitro 3'' end during incubation in a cell-free system of yeast. By contrast premRNA synthesized on the template with the core signal alone was processed but much less efficiently. No such processing was seen when the pre-mRNA either lacked the core signal or contained it in the reverse orientation.