The Poly(A)-Binding Protein Nuclear 1 Suppresses Alternative Cleavage and Polyadenylation Sites
The Poly(A)-Binding Protein Nuclear 1 Suppresses Alternative Cleavage and Polyadenylation Sites
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DOI：
10.1016/j.cell.2012.03.022
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发表时间：
2012-04-27
期刊：
影响因子：
64.5
通讯作者：
Agami, Reuven
中科院分区：
文献类型：
--
作者：
Jenal, Mathias;Elkon, Ran;Agami, Reuven
选择性裂解和多聚腺苷酸化(APA)是基因调控的一个重要层面。控制APA的因素在很大程度上是未知的。我们为APA开发了一种基于报告者的RNAi筛选，并确定PABPN1是这一过程的调节因子。对人类细胞中APA的全基因组分析表明，PABPN1的缺失导致30个非翻译区的广泛缩短。信使RNA转录、稳定性分析和体外切割分析表明，近端裂解位点的使用增加是潜在的机制。使用Cyclin D1作为测试案例，我们证明了近端css的增强使用折衷了microRNA介导的抑制。PABPN1三联重复扩增(TrePABPN1)可导致常染色体显性眼咽肌营养不良症(OPMD)。在OPMD小鼠模型和人类细胞中，trePABPN1的表达都引起了近端CS使用的广泛诱导，与内源性PABPN1结合及其在核聚集体中的固存有关。我们的结果阐明了PABPN1作为APA抑制因子的一个新功能。
Alternative cleavage and polyadenylation (APA) is emerging as an important layer of gene regulation. Factors controlling APA are largely unknown. We developed a reporter-based RNAi screen for APA and identified PABPN1 as a regulator of this process. Genome-wide analysis of APA in human cells showed that loss of PABPN1 resulted in extensive 30 untranslated region shortening. Messenger RNA transcription, stability analyses, and in vitro cleavage assays indicated enhanced usage of proximal cleavage sites (CSs) as the underlying mechanism. Using Cyclin D1 as a test case, we demonstrated that enhanced usage of proximal CSs compromises microRNA-mediated repression. Triplet-repeat expansion in PABPN1 (trePABPN1) causes autosomal-dominant oculopharyngeal muscular dystrophy (OPMD). The expression of trePABPN1 in both a mouse model of OPMD and human cells elicited broad induction of proximal CS usage, linked to binding to endogenous PABPN1 and its sequestration in nuclear aggregates. Our results elucidate a novel function for PABPN1 as a suppressor of APA.