Cytoplasmic long noncoding RNAs are frequently bound to and degraded at ribosomes in human cells.
Cytoplasmic long noncoding RNAs are frequently bound to and degraded at ribosomes in human cells.
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DOI：
10.1261/rna.053561.115
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发表时间：
2016-06
期刊：
影响因子：
--
通讯作者：
Johnson R
中科院分区：
文献类型：
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作者：
Carlevaro-Fita J;Rahim A;Guigó R;Vardy LA;Johnson R
近期的足迹研究有一个令人惊讶的发现：长链非编码RNA（lncRNAs）与核糖体存在物理相互作用。然而，这些发现仍存在争议，并且所涉及的细胞质lncRNAs的总体比例尚不清楚。在此，我们利用多聚核糖体图谱分析结合掺入标准物的微阵列分析，对人类细胞系中经过严格筛选的lncRNAs的细胞质及与核糖体相关的群体进行了全面、绝对的评估。54%的表达的lncRNAs在细胞质中被检测到。其中大多数（70%）有超过50%的细胞质拷贝与多聚核糖体组分相关。在用嘌呤霉素破坏核糖体后，这些相互作用消失。多聚核糖体lncRNAs具有一些类似mRNA 5′端的特征，包括加帽和5′非翻译区长度。另一方面，非多聚核糖体的“游离细胞质”lncRNAs具有更保守的启动子，并且在不同细胞类型中的表达范围更广。多聚核糖体lncRNAs的外显子缺乏内源性逆转录病毒插入，这表明重复元件在lncRNA定位中起作用。最后，我们表明阻断核糖体延伸会导致许多相关lncRNAs的稳定。综合这些发现表明，核糖体是大多数细胞质长链非编码RNAs的默认目的地，并且可能在它们的降解中起作用。
Recent footprinting studies have made the surprising observation that long noncoding RNAs (lncRNAs) physically interact with ribosomes. However, these findings remain controversial, and the overall proportion of cytoplasmic lncRNAs involved is unknown. Here we make a global, absolute estimate of the cytoplasmic and ribosome-associated population of stringently filtered lncRNAs in a human cell line using polysome profiling coupled to spike-in normalized microarray analysis. Fifty-four percent of expressed lncRNAs are detected in the cytoplasm. The majority of these (70%) have >50% of their cytoplasmic copies associated with polysomal fractions. These interactions are lost upon disruption of ribosomes by puromycin. Polysomal lncRNAs are distinguished by a number of 5′ mRNA-like features, including capping and 5′UTR length. On the other hand, nonpolysomal “free cytoplasmic” lncRNAs have more conserved promoters and a wider range of expression across cell types. Exons of polysomal lncRNAs are depleted of endogenous retroviral insertions, suggesting a role for repetitive elements in lncRNA localization. Finally, we show that blocking of ribosomal elongation results in stabilization of many associated lncRNAs. Together these findings suggest that the ribosome is the default destination for the majority of cytoplasmic long noncoding RNAs and may play a role in their degradation.