Multiple transcript cleavage precedes polymerase release in termination by RNA polymerase II
Multiple transcript cleavage precedes polymerase release in termination by RNA polymerase II
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DOI：
10.1016/s0092-8674(01)00372-5
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发表时间：
2001-06-01
期刊：
影响因子：
64.5
通讯作者：
Proudfoot, NJ
中科院分区：
文献类型：
--
作者：
Dye, MJ;Proudfoot, NJ
多聚(A)信号诱导RNA聚合酶II(PolII)转录终止的要求已经确立。然而，对polII转录终止的实际过程知之甚少。本文提出的证据，基于对人类β-和epsilon-珠蛋白基因的新生转录本的分析，表明PolII转录终止涉及两个不同的和时间上分离的事件。第一个事件，称为终止前切割(PTC)，是由位于Poly(A)位点下游的序列区段介导的，它似乎促进了新生转录本的异质性切割。第二个事件是PolII从DNA模板上脱离，需要聚合酶转录PTC序列和功能性聚(A)位点。
The requirement of poly(A) signals to elicit transcription termination of RNA polymerase II (pol II) is firmly established. However, little else is known about the actual process of pol II transcription termination. Evidence presented in this paper, based on analysis of nascent transcripts of the human beta- and epsilon -globin genes, demonstrates that pol II transcription termination involves two distinct and temporally separate events. The first event, termed pretermination cleavage (PTC), is mediated by sequence tracts located downstream of the poly(A) site which appear to promote heterogeneous cleavage of the nascent transcript. The second event, in which pol II disengages from the DNA template, requires that polymerase has transcribed both a PTC sequence tract and a functional poly(A) site.