Stress granules (SGs) are condensates of mRNPs that form in response to stress. SGs arise by multivalent protein-protein, protein-RNA, and RNA-RNA interactions. However, the role of RNA-RNA interactions in SG assembly remains understudied. Here, we describe a yeast SG reconstitution system that faithfully recapitulates SG assembly in response to trigger RNAs. SGs assembled by stem-loop RNA triggers are ATP-sensitive, regulated by helicase/chaperone activity, and exhibit the hallmarks of maturation observed for SG proteins that phase-separate in vitro. Additionally, the fraction of total RNA that phase-separates in vitro is sufficient to trigger SG formation. However, condensation of NFT1 mRNA, an enriched transcript in this population, can only assemble an incomplete SG. These results suggest that networks of distinct transcripts are required to form a canonical SG and provide a platform for dissecting the interplay between the transcriptome and ATP-dependent remodeling in SG formation.

应力颗粒（SGs​​）是响应压力而形成的mRNP的缩合物。SGs通过多价蛋白质-蛋白质，蛋白质-RNA和RNA-RNA相互作用产生。然而，RNA-RNA相互作用在SG组装中的作用仍未被研究。在这里，我们描述了酵母SG重组系统，该系统忠实地概括了SG组装以响应触发RNA。由茎环RNA触发物组装的SG对ATP敏感，受解旋酶/分子伴侣活性调节，并且表现出在体外相分离的SG蛋白中观察到的成熟标志。此外，总RNA在体外发生相分离的比例足以触发SG的形成。但是，NFT1 mRNA的缩合（该种群中丰富的转录本）只能组装不完整的SG。这些结果表明，需要不同转录本的网络来形成规范的SG，并为解剖转录组和ATP依赖的SG重构之间的相互作用提供了平台。