Splice site choice in a complex transcription unit containing multiple inefficient polyadenylation signals.
Splice site choice in a complex transcription unit containing multiple inefficient polyadenylation signals.
复制标题
包含多个低效多腺苷酸化信号的复杂转录单元中的剪接位点选择。
DOI：
10.1128/mcb.11.10.5291-5300.1991
复制
发表时间：
1991
影响因子：
5.3
通讯作者：
Carmichael,GG
中科院分区：
文献类型：
--
作者：
Luo,Y;Carmichael,GG
在一个由两个串联但不完全相同的多瘤病毒晚期转录单位组成的模型系统中，研究了多聚腺苷化和剪接之间的关系。这个模型系统利用了多瘤病毒晚期转录终止和多聚腺苷基化信号，这些信号足够弱，可以产生许多具有重复内含子、外显子和聚(A)位点的多基因组长度的初级转录本。这种双基因组结构包含两种类型的外显子，分别以3‘和5’剪接点(L1和L2)和3‘剪接点和多聚(A)点(V1和V2)为边界。L1和L2外显子可以彼此区分，但保留了相同的侧翼RNA处理信号，就像V1和V2外显子的情况一样。对从转染该构建体及其衍生物的小鼠细胞获得的细胞质RNA的分析揭示如下：(I)V1和V2外显子在前mRNA加工过程中经常被跳过，而L1和L2外显子不被跳过，(Ii)没有消息包含内部的、未使用的多聚腺苷酸化信号，(Iii)Poly(A)对于上游3‘剪接位点的选择不需要Poly(A)位点选择，(Iv)当两个串联的Poly(A)位点被放置在3’剪接位点的下游时，尽管转录可以通过这两个位点，但第一Poly(A)位点几乎完全被选择，(V)在这两个串联的Poly(A)位点之间放置3‘剪接位点允许选择更远的位点。这些和其他可用的数据与一个模型最一致，在该模型中，末端外显子是通过3‘剪接位点与最近的可用的下游聚(A)位点的坐标选择和使用而产生的。
The relationship between polyadenylation and splicing was investigated in a model system consisting of two tandem but nonidentical polyomavirus late transcription units. This model system exploits the polyomavirus late transcription termination and polyadenylation signals, which are sufficiently weak to allow the production of many multigenome-length primary transcripts with repeating introns, exons, and poly(A) sites. This double-genome construct contains exons of two types, those bordered by 3′ and 5′ splice sites (L1 and L2) and those bordered by a 3′ splice site and a poly(A) site (V1 and V2). The L1 and L2 exons are distinguishable from one another but retain identical flanking RNA processing signals, as is the case for the V1 and V2 exons. Analysis of cytoplasmic RNAs obtained from mouse cells transfected with this construct and its derivatives revealed the following, (i) V1 and V2 exons are often skipped during pre-mRNA processing, while L1 and L2 exons are not skipped, (ii) No messages contain internal, unused polyadenylation signals, (iii) Poly(A) site choice is not required for the selection of an upstream 3′ splice site, (iv) When two tandem poly(A) sites are placed downstream of a 3′ splice site, the first poly(A) site is chosen almost exclusively, even though transcription can proceed past both sites, (v) Placing a 3′ splice site between these two tandem poly(A) sites allows the more distal site to be chosen. These and other available data are most consistent with a model in which terminal exons are produced by the coordinate selection and use of a 3′ splice site with the nearest available downstream poly(A) site.