Aggregation of SND1 in Stress Granules is Associated with the Microtubule Cytoskeleton During Heat Shock Stimulus.

Stress granules (SGs) are dynamic dense structures in the cytoplasm that form in response to a variety of environmental stress stimuli. Staphylococcal nuclease and Tudor domain containing 1 (SND1) is a type of RNA‐binding protein and has been identified as a transcriptional co‐activator. Our previous studies have shown that SND1 is a component of the stress granule, which forms under stress conditions. Here, we observed that SND1 granules were often surrounded by ɑ‐tubulin‐microtubules in 45°C‐treated HeLa cells at 15 min or colocalized with microtubules at 30 or 45 min. Furthermore, Nocodazole‐mediated microtubule depolymerization could significantly affect the efficient recruitment of SND1 proteins to the SGs during heat shock stress. In addition, the 45°C heat shock mediated the enhancement of eIF2α phosphorylation, which was not affected by treatment with Nocodazole, an agent that disrupts the cytoskeleton. The intact microtubule cytoskeletal tracks are important for the efficient assembly of SND1 granules under heat shock stress and may facilitate SND1 shuttling between cytoplasmic RNA foci. Anat Rec, 300:2192–2199, 2017. © 2017 The Authors The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

应激颗粒（SGs）是细胞质中的动态致密结构，由多种环境应激刺激诱导形成。含葡萄球菌核酸酶和都铎结构域蛋白1（SND1）是一种RNA结合蛋白，已被鉴定为转录共激活因子。我们之前的研究表明，SND1是应激颗粒的一个组分，在应激条件下形成。在此，我们观察到在经45°C处理15分钟的HeLa细胞中，SND1颗粒常常被α -微管蛋白 - 微管环绕，在30或45分钟时则与微管共定位。此外，诺考达唑介导的微管解聚可显著影响热激应激过程中SND1蛋白向应激颗粒的有效募集。另外，45°C热激介导了eIF2α磷酸化的增强，这不受诺考达唑（一种破坏细胞骨架的试剂）处理的影响。完整的微管细胞骨架轨道对于热激应激下SND1颗粒的有效组装很重要，并且可能促进SND1在细胞质RNA焦点之间的穿梭。《解剖学记录》，2017年，300卷：2192 - 2199页。© 2017作者，《解剖学记录》由威利期刊公司代表美国解剖学家协会出版。