Abstract：
The translation elongation factor 1α (EF1α) protein is a highly conserved G protein that is crucial for protein translation in all eukaryotic organisms. EF1α quickly became insoluble at temperatures 42 °C treatment for 2h in vitro, but generally remained soluble in vivo even after being exposed to temperatures as high as 45 °C for an extended period, which suggests that protective mechanisms exist for keeping EF1α soluble in plant cells under heat stress. EF1α had fast in vivo insolubilization when exposed to 45 °C, resulting in about 40% of the protein aggregating after 9 h. Given its established role in protein translation, heat-induced aggregation is most likely to impact the function of the elongation factor. Overexpression of constitutive mutants in both GTP-bound and GDP-bound forms of EF1α resulted in significantly decreased heat tolerance. These findings provide evidence to support the critical role of EF1α, a thermosensitive protein, in the heat tolerance of plants.
摘要：
翻译延伸因子1α（EF1α）蛋白是一种高度保守的G蛋白，对于所有真核生物中的蛋白质翻译至关重要。EF1α在42°C的温度下在体外处理2h迅速变得不溶，但即使在长时间暴露于高达45°C的温度后，通常仍可在体内溶解，这表明在热胁迫下存在保持EF1α在植物细胞中可溶的保护机制。当暴露于45°C时，EF1α在体内快速不溶解，导致约40%的蛋白质在9小时后聚集。鉴于其在蛋白质翻译中的既定作用，热诱导的聚集最有可能影响伸长因子的功能。EF1α的GTP结合形式和GDP结合形式的组成型突变体的过表达导致耐热性显着降低。这些发现为支持EF1α的关键作用提供了证据，一种热敏蛋白,植物的耐热性。
