RNA performs a remarkable range of functions, such as RNA processing, chromosome maintenance and dosage compensation. Technologies that robustly and specifically image RNA in its native state are highly desirable, as these technologies can help researchers clarify the localization and functionality of diverse RNAs. Here, we describe the development of a sequence-activated fluorescent RNA (SaFR) technique. In SaFR, in the absence of target RNA, the structure of fluorogenic RNA is disrupted by the invader sequence, and the ability to activate the Pepper’s cognate fluorophores is lost as a result. In the presence of target RNA, SaFR undergoes conformational reorganization and transforms into the fluorogenic conformation of Pepper, enabling the activation of fluorophores to produce fluorescent signals. SaFR exhibits favourable properties, such as large dynamic ranges, high specificity and fast fluorescence generation. Further studies showed that exogenous or endogenous RNAs can be tracked in live and fixed cells through SaFR. We further demonstrated the usefulness of SaFR in monitoring the assembly and disassembly of stress granules in real-time. Overall, this study offers a robust and versatile tool for labelling and imaging endogenous RNA in cells, which will be useful for clarifying the functionality and molecular mechanism of RNA.

中文翻译：

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使用序列激活的荧光 RNA 探针对活细胞中的内源性 RNA 进行成像


RNA 具有一系列显著的功能，例如 RNA 加工、染色体维持和剂量补偿。非常需要能够在天然状态下对 RNA 进行稳健和特异性成像的技术，因为这些技术可以帮助研究人员阐明不同 RNA 的定位和功能。在这里，我们描述了序列激活荧光 RNA （SaFR） 技术的开发。在 SaFR 中，在没有靶 RNA 的情况下，荧光 RNA 的结构被入侵序列破坏，因此失去了激活 Pepper 同源荧光团的能力。在靶 RNA 存在下，SaFR 发生构象重组并转化为 Pepper 的荧光构象，从而能够激活荧光团以产生荧光信号。SaFR 表现出良好的特性，例如大动态范围、高特异性和快速荧光生成。进一步的研究表明，可以通过 SaFR 在活细胞和固定细胞中追踪外源性或内源性 RNA。我们进一步证明了 SaFR 在实时监测应力颗粒的组装和拆卸方面的有效性。总体而言，本研究为标记和成像细胞中的内源性 RNA 提供了一种强大的多功能工具，这将有助于阐明 RNA 的功能和分子机制。