Stress granules (SGs) are cytoplasmic condensates composed of various proteins and RNAs that protect translation-associated machinery from harmful conditions during stress. However, the method of spatio-temporal inactivation of condensates such as SGs in live cells to study cellular phenotypes is still in the process of being demonstrated. Here, we show that the inactivation of SG by chromophore-associated light inactivation (CALI) using a genetically encoded red fluorescence protein (SuperNova-Red) as a photosensitizer leads to differences in cell viability during recovery from hyperosmotic stress. CALI delayed the disassembly kinetics of SGs during recovery from hyperosmotic stress. Consequently, CALI could inactivate the SGs, and the cellular fate due to SGs could be analyzed. Furthermore, CALI is an effective spatiotemporal knockdown method for intracellular condensates/aggregates and would contribute to the elucidation of importance of such condensates/aggregates.

中文翻译：

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通过发色团相关的光失活导致应激颗粒功能障碍

应激颗粒 (SG) 是由各种蛋白质和 RNA 组成的细胞质凝聚物，可在应激期间保护翻译相关机制免受有害条件的影响。然而，通过在活细胞中时空失活SG等凝聚物来研究细胞表型的方法仍在论证过程中。在这里，我们发现，使用基因编码的红色荧光蛋白（SuperNova-Red）作为光敏剂，通过发色团相关光灭活（CALI）来灭活 SG，导致高渗应激恢复过程中细胞活力的差异。 CALI 延迟了高渗应激恢复过程中 SG 的分解动力学。因此，CALI 可以使 SG 失活，并且可以分析 SG 引起的细胞命运。此外，CALI 是一种有效的细胞内凝聚物/聚集物的时空敲低方法，并将有助于阐明此类凝聚物/聚集物的重要性。