Acute Heat Stress Leads to Reversible Aggregation of Nuclear Proteins into Nucleolar Rings in Fission Yeast
Acute Heat Stress Leads to Reversible Aggregation of Nuclear Proteins into Nucleolar Rings in Fission Yeast
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DOI：
10.1016/j.celrep.2020.108377
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发表时间：
2020-11-10
期刊：
影响因子：
8.8
通讯作者：
Daga, Rafael R.
中科院分区：
文献类型：
--
作者：
Gallardo, Paola;Real-Calderon, Paula;Daga, Rafael R.
在急性热应激（HS）时，总体mRNA转录、加工和输出被抑制，导致细胞生长停滞。然而，细胞如何关闭mRNA代谢尚不完全清楚。在这里，我们表明，急性HS的结果在分离和聚集的多个核和核仁蛋白成环状结构位于核仁周边（核仁环[NuRs]）。NuR螯合核mRNA代谢和核孔复合体功能所需的必需因子，以及细胞周期调节因子。当细胞切换回生长温度时，NuR解聚，其组分以Hsf1和Hsp104依赖的方式重新定位到其功能环境中，并伴随着细胞生长的重新启动。这些发现突出了可逆蛋白质聚集对抑制细胞核中总体RNA相关活性的贡献及其在急性HS期间维持细胞稳态的功能相关性。
Upon acute heat stress (HS), overall mRNA transcription, processing, and export are inhibited, leading to cell growth arrest. However, how cells turn off mRNA metabolism is not fully understood. Here, we show that acute HS results in the segregation and aggregation of multiple nuclear and nucleolar proteins into ringlike structures located at the nucleolar periphery (nucleolar rings [NuRs]). NuRs sequester essential factors required for nuclear mRNA metabolism and nuclear pore complex function, as well as cell-cycle regulators. When cells are switched back to growing temperatures, NuRs disaggregate, and their components relocate to their functional environments in an Hsf1- and Hsp104-dependent manner, and concomitantly with the reinitiation of cell growth. These findings highlight the contribution of reversible protein aggregation to the inhibition of overall RNA-related activities in the nucleus and its functional relevance in the maintenance of cellular homeostasis during acute HS.