Multi-UTR genes are widely transcribed but show cell type-specific 3′UTR isoform expression. As transcriptional enhancers regulate mRNA expression, we investigated if they also regulate mRNA isoform expression. Deletion of an endogenous enhancer of a multi-UTR gene did not impair transcript production but prevented a switch in 3′UTR isoform expression. Also, the same enhancers are able to increase transcript production in the context of single-UTR gene promoters, but they increase 3′ end processing activity when paired with multi-UTR gene promoters. We show that transcription factors regulate processing activity of weak polyadenylation sites to control cell type-specific alternative 3′UTR isoform expression of widely expressed genes.

中文翻译：

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增强子调节 3' 末端加工活动以控制替代 3'UTR 亚型的表达

多 UTR 基因被广泛转录，但显示出细胞类型特异性 3'UTR 亚型表达。由于转录增强子调节 mRNA 表达，我们研究了它们是否也调节 mRNA 异构体的表达。删除多 UTR 基因的内源增强子不会损害转录产物的产生，但会阻止 3'UTR 同种型表达的转换。此外，在单 UTR 基因启动子的情况下，相同的增强子能够增加转录产物的产生，但当与多 UTR 基因启动子配对时，它们会增加 3' 端加工活性。我们表明转录因子调节弱聚腺苷酸化位点的加工活性，以控制广泛表达基因的细胞类型特异性替代 3'UTR 亚型表达。