Differential nuclear import regulates nuclear RNA inheritance following mitosis.
Differential nuclear import regulates nuclear RNA inheritance following mitosis.
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DOI：
10.1091/mbc.e23-01-0004
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发表时间：
2023-04-01
影响因子：
3.3
通讯作者：
Sharp, Judith A.
中科院分区：
文献类型：
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作者：
Blower, Michael D.;Wang, Wei;Sharp, Judith A.
有丝分裂导致染色质结构的戏剧性重组，以促进染色体紧凑和子代细胞的分离。因此，有丝分裂的进入伴随着转录沉默和大多数染色质结合的RNA从染色体上移除。当细胞退出有丝分裂时，染色质迅速解聚，转录重新启动，形成差异基因表达波。然而，人们对染色质结合的RNA在细胞分裂后的命运知之甚少。在这里，我们探索了前一个细胞周期的核RNA是否存在于有丝分裂后的G1核中。我们发现，在有丝分裂后，有一半的核RNA是以转录独立的方式遗传的。有趣的是，SnRNAU2可以有效地被G1核遗传，而lncRNAs NEAT1和MALAT1在有丝分裂后没有遗传。我们发现，假设将RNA拴在DNA上的核蛋白SAF-A在核RNA遗传中没有发挥重要作用，表明RNA遗传的机制可能不涉及具有染色质结合活性的RNA伴侣。相反，我们观察到RNA遗传的时间表明，在核膜重组后，一组选定的核RNA被重新输入到核中。我们的工作表明，在有丝分裂后，有一部分来自前一个细胞周期的核RNA是重新输入的，并表明有丝分裂可能是重置lncRNAs与染色质相互作用的时间。
Mitosis results in a dramatic reorganization of chromatin structure to promote chromosome compaction and segregation to daughter cells. Consequently, mitotic entry is accompanied by transcriptional silencing and removal of most chromatin-bound RNA from chromosomes. As cells exit mitosis, chromatin rapidly decondenses and transcription restarts as waves of differential gene expression. However, little is known about the fate of chromatin-bound RNAs following cell division. Here we explored whether nuclear RNA from the previous cell cycle is present in G1 nuclei following mitosis. We found that half of all nuclear RNA is inherited in a transcription-independent manner following mitosis. Interestingly, the snRNA U2 is efficiently inherited by G1 nuclei, while the lncRNAs NEAT1 and MALAT1 show no inheritance following mitosis. We found that the nuclear protein SAF-A, which is hypothesized to tether RNA to DNA, did not play a prominent role in nuclear RNA inheritance, indicating that the mechanism for RNA inheritance may not involve RNA chaperones that have chromatin-binding activity. Instead, we observe that the timing of RNA inheritance indicates that a select group of nuclear RNAs are reimported into the nucleus after the nuclear envelope has reassembled. Our work demonstrates that there is a fraction of nuclear RNA from the previous cell cycle that is reimported following mitosis and suggests that mitosis may serve as a time to reset the interaction of lncRNAs with chromatin.