Nuclear retention element recruits U1 snRNP components to restrain spliced lncRNAs in the nucleus
Nuclear retention element recruits U1 snRNP components to restrain spliced lncRNAs in the nucleus
复制标题
核保留元件招募 U1 snRNP 成分来抑制细胞核中剪接的 lncRNA
DOI：
10.1080/15476286.2019.1620061
复制
发表时间：
2019-08-03
期刊：
影响因子：
4.1
通讯作者：
Lei, Haixin
中科院分区：
文献类型：
--
作者：
Azam, Sikandar;Hou, Shuai;Lei, Haixin
摘要与剪接的mRNAs的胞浆定位不同，许多剪接的lncRNAs定位于细胞核。为了研究这一机制，我们以lncRNA MEG3为报告基因，定位了一个有效的核保持元件(NRE)，该元件的缺失导致MEG3从细胞核向细胞质输出。NRE的插入导致剪接的lncRNA和剪接的mRNA的核滞留。我们进一步纯化了体外组装在NRE上的RNP，并用质谱仪对其进行了鉴定。通过siRNA筛选发现，U1 SNRNP组分SNRPA、SNRNP70或SNRPD2的缺失导致了MEG3报告转录本的显著细胞质定位。在HFF1细胞中共同敲除这些因素导致内源性lncRNAs胞浆分布增加。综上所述，这些数据支持一个模型，即U1 SnRNP组分通过与核保留元件的相互作用抑制核内剪接的lncRNAs。
ABSTRACT In contrast to cytoplasmic localization of spliced mRNAs, many spliced lncRNAs are localized in the nucleus. To investigate the mechanism, we used lncRNA MEG3 as a reporter and mapped a potent nuclear retention element (NRE), deletion of this element led to striking export of MEG3 from the nucleus to the cytoplasm. Insertion of the NRE resulted in nuclear retention of spliced lncRNA as well as spliced mRNA. We further purified RNP assembled on the NRE in vitro and identified the proteins by mass spectrometry. Screen using siRNA revealed depletion of U1 snRNP components SNRPA, SNRNP70 or SNRPD2 caused significant cytoplasmic localization of MEG3 reporter transcripts. Co-knockdown these factors in HFF1 cells resulted in an increased cytoplasmic distribution of endogenous lncRNAs. Together, these data support a model that U1 snRNP components restrain spliced lncRNAs in the nucleus via the interaction with nuclear retention element.