Nuclear antisense RNA induces extensive adenosine modifications and nuclear retention of target transcripts
Nuclear antisense RNA induces extensive adenosine modifications and nuclear retention of target transcripts
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DOI：
10.1073/pnas.94.8.3542
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发表时间：
1997-04-15
影响因子：
11.1
通讯作者：
Carmichael, GG
中科院分区：
文献类型：
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作者：
Kumar, M;Carmichael, GG
反义RNA可以调节许多真核基因的表达，但对其流行程度和作用机制知之甚少。我们已经使用了一个模型系统，其中反义控制可以研究遗传和生化。在多瘤病毒感染后期，早链mRNA水平被来自晚链的核反义RNA下调。分析早期链转录分离感染后期发现广泛的碱基修饰。在许多转录本中，几乎一半的腺苷被改变为肌苷或鸟苷。这些结果表明双链RNA腺苷脱氨酶或相关酶对RNA双链体的修饰。仅检测修饰RNA的探针显示，这些分子并不高度不稳定，但在细胞核内积累，因此对基因表达是惰性的。反义诱导的修饰可以解释大多数或所有观察到的调节，在感染后期通常观察到的早期链RNA水平降低是由于许多转录物对标准杂交探针不可见的事实。这项工作表明，类似的反义介导的控制机制也可能在未感染的真核细胞的生理条件下运作，并导致建议，有一个新的池的核RNA，不能看到许多分子探针迄今为止使用。
Antisense RNA may regulate the expression of a number of eukaryotic genes, but little is known about its prevalence or mechanism of action. We have used a model system in which antisense control can be studied both genetically and biochemically. Late in polyoma virus infection, early-strand mRNA levels are down-regulated by nuclear antisense RNA from the late strand. Analysis of early-strand transcripts isolated late in infection revealed extensive base modifications. In many transcripts almost half of the adenosines were altered to inosines or guanosines. These results suggest modification of RNA duplexes by double-stranded RNA adenosine deaminase or a related enzyme. Probes that detect only modified RNAs revealed that these molecules are not highly unstable, but accumulate within the nucleus and are thus inert for gene expression. Antisense-induced modifications can account for most or all of the observed regulation, with the lowered levels of early-strand RNAs commonly observed late in infection resulting from the fact that many transcripts are invisible to standard hybridization probes. This work suggests that similar antisense mediated control mechanisms may also operate under physiological conditions in uninfected eukaryotic cells, and leads to the proposal that there is a novel pool of nuclear RNAs that cannot be seen with many molecular probes heretofore used.