The Stress Granule RNA-Binding Protein TIAR-1 Protects Female Germ Cells from Heat Shock in Caenorhabditis elegans.
The Stress Granule RNA-Binding Protein TIAR-1 Protects Female Germ Cells from Heat Shock in Caenorhabditis elegans.
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DOI：
10.1534/g3.115.026815
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发表时间：
2016-04-07
期刊：
影响因子：
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通讯作者：
Navarro RE
中科院分区：
文献类型：
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作者：
Huelgas-Morales G;Silva-García CG;Salinas LS;Greenstein D;Navarro RE
为了应对应激条件，真核细胞启动了一系列调节程序来保护蛋白质组。一种主要的保护性反应涉及阻止蛋白质翻译和形成应激颗粒，即含有保守的RNA结合蛋白TIA-1和TIAR的细胞质核糖核蛋白复合体。应激颗粒反应被认为保存了mRNA，以便在条件改善时进行翻译。对于生殖系细胞-有性繁殖所需的不朽细胞谱系-保护免受应激对物种的永久存在至关重要，但应激颗粒调节机制如何部署在动物繁殖中尚不完全清楚。在这里，我们表明，应激颗粒蛋白TIAR-1保护秀丽线虫生殖系免受热休克的不利影响。在热休克后，与野生型相比，含有TIAR-1强烈功能丧失突变的动物表现出显著的生育能力降低。对热休克蛋白启动子的分析表明，TIAR-1突变体表现出受损的热休克反应。我们观察到，在几种应激条件下，TIAR-1与性腺核心和卵母细胞中的颗粒有关。性腺核心和卵母细胞颗粒都是动态结构，依赖于翻译；蛋白质合成抑制剂改变了它们的形成。尽管如此，TIAR-1仅是性腺核心颗粒形成所必需的。有趣的是，生殖细胞在热休克后发育出可存活的胚胎似乎并不需要性腺核心颗粒。这表明TIAR-1能够保护生殖系免受热应激，而不依赖于这些结构。
In response to stressful conditions, eukaryotic cells launch an arsenal of regulatory programs to protect the proteome. One major protective response involves the arrest of protein translation and the formation of stress granules, cytoplasmic ribonucleoprotein complexes containing the conserved RNA-binding proteins TIA-1 and TIAR. The stress granule response is thought to preserve mRNA for translation when conditions improve. For cells of the germline—the immortal cell lineage required for sexual reproduction—protection from stress is critically important for perpetuation of the species, yet how stress granule regulatory mechanisms are deployed in animal reproduction is incompletely understood. Here, we show that the stress granule protein TIAR-1 protects the Caenorhabditis elegans germline from the adverse effects of heat shock. Animals containing strong loss-of-function mutations in tiar-1 exhibit significantly reduced fertility compared to the wild type following heat shock. Analysis of a heat-shock protein promoter indicates that tiar-1 mutants display an impaired heat-shock response. We observed that TIAR-1 was associated with granules in the gonad core and oocytes during several stressful conditions. Both gonad core and oocyte granules are dynamic structures that depend on translation; protein synthesis inhibitors altered their formation. Nonetheless, tiar-1 was required for the formation of gonad core granules only. Interestingly, the gonad core granules did not seem to be needed for the germ cells to develop viable embryos after heat shock. This suggests that TIAR-1 is able to protect the germline from heat stress independently of these structures.