Splice site selection dominates over poly(A) site choice in RNA production from complex adenovirus transcription units.
Splice site selection dominates over poly(A) site choice in RNA production from complex adenovirus transcription units.
复制标题
在复杂腺病毒转录单位的 RNA 生产中，剪接位点选择比 Poly(A) 位点选择占主导地位。
DOI：
10.1002/j.1460-2075.1988.tb03050.x
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Nevins,JR
中科院分区：
文献类型：
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作者：
Adami,G;Nevins,JR
腺病毒晚期基因组织在一个复杂的转录单元中，其中多个RNA的产生由特定的RNA加工事件控制。增加复杂性的事实是，早期的E3转录单位完全包含在后期的转录单位。在这个重叠区域内存在剪接事件和每个转录单元特有的聚(A)位点选择。在感染早期，E3剪接位点几乎完全被使用，L4 poly(A)位点的使用很少，而在感染后期则相反。使用含有完整E3转录单元的质粒，我们证明位于第一个E3内含子的L4 poly(a)位点在模拟感染细胞或晚期感染细胞中都没有使用；如果相同的转录单位由主要的晚期启动子驱动，也不会使用它。此外，聚(A)位点的性质似乎不重要，因为如果插入L4聚(A)位点，E3聚(A)位点也不会在内含子中使用。因此，剪接位点选择似乎在poly(A)位点选择上占主导地位。这一结论被观察证实，删除E3剪接供体（5 ' s）或E3剪接受体（3 ' s）允许使用L4 poly(A)位点。最后，当在启动子和E3加工位点之间插入额外的序列，包括来自L4区域和三方先导子的剪接信号时，也使用了E3内含子内的L4 poly(A)位点。剪接似乎是控制E3/L4 rna产生的主要事件。
The adenovirus late genes are organized in a complex transcription unit in which the production of multiple RNAs is controlled by specific RNA processing events. Adding to the complexity is the fact that the early E3 transcription unit is wholly contained within the late transcription unit. Within this overlapping region there are splicing events and poly(A) site choices specific to each transcription unit. Early in infection, there is near exclusive use of the E3 splice sites with little L4 poly(A) site use whereas the reverse is true late in infection. Using a plasmid containing an intact E3 transcription unit, we demonstrate that the L4 poly(A) site, located in the first E3 intron, is not used either in a mock‐infected cell or a late infected cell; nor is it used if the same transcription unit is driven by the major late promoter. In addition, the nature of the poly(A) site appeared to be unimportant since the E3 poly(A) site was also not used in the intron if inserted in place of the L4 poly(A) site. Thus, splice site selection appears to dominate over poly(A) site choice. This conclusion was confirmed by the observation that deletion of either the E3 splice donor (5′ss) or the E3 splice acceptor (3′ss) allowed the use of the L4 poly(A) site. Finally, the L4 poly(A) site within the E3 intron was also used when additional sequence, including splicing signals from the L4 region and the tripartite leader, was inserted between the promoter and the E3 processing sites. It appears that splicing is the dominant event in governing production of E3/L4 RNAs.