Numerous membrane-less organelles, composed of a combination of RNA and proteins, are observed in the nucleus and cytoplasm of eukaryotic cells. These RNP granules include stress granules (SGs), processing bodies (PBs), Cajal bodies, and nuclear speckles. An unresolved question is how frequently RNA molecules are required for the integrity of RNP granules in either the nucleus or cytosol. To address this issue, we degraded intracellular RNA in either the cytosol or the nucleus by the activation of RNase L and examined the impact of RNA loss on several RNP granules. We find the majority of RNP granules, including SGs, Cajal bodies, nuclear speckles, and the nucleolus, are altered by the degradation of their RNA components. In contrast, PBs and super-enhancer complexes were largely not affected by RNA degradation in their respective compartments. RNA degradation overall led to the apparent dissolution of some membrane-less organelles, whereas others reorganized into structures with altered morphology. These findings highlight a critical and widespread role of RNA in the organization of several RNP granules.

中文翻译：

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RNA 是多个核和细胞质无膜 RNP 颗粒的完整性所必需的。

在真核细胞的细胞核和细胞质中观察到许多由 RNA 和蛋白质组合组成的无膜细胞器。这些RNP颗粒包括应力颗粒（SGs​​）、处理体（PBs）、Cajal体和核散斑。一个未解决的问题是核或胞质溶胶中 RNP 颗粒的完整性需要 RNA 分子的频率。为了解决这个问题，我们通过激活 RNase L 降解细胞质或细胞核中的细胞内 RNA，并检查了 RNA 损失对几个 RNP 颗粒的影响。我们发现大多数 RNP 颗粒，包括 SG、Cajal 小体、核斑点和核仁，都因其 RNA 成分的降解而发生改变。相比之下，PBs 和超级增强子复合物在很大程度上不受其各自隔室中 RNA 降解的影响。RNA 降解总体上导致一些无膜细胞器的明显溶解，而另一些则重组为形态改变的结构。这些发现强调了 RNA 在几种 RNP 颗粒组织中的关键和广泛作用。