Localization of the translational guanine nucleotide exchange factor eIF2B - A common theme for GEFs?
Localization of the translational guanine nucleotide exchange factor eIF2B - A common theme for GEFs?
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DOI：
10.4161/cc.5.7.2607
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发表时间：
2006-04-01
期刊：
影响因子：
4.3
通讯作者：
Ashe, Mark P.
中科院分区：
文献类型：
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作者：
Campbell, Susan G.;Ashe, Mark P.
真核起始因子2B（eIF2B）在蛋白质合成中起着重要的再循环作用。作为eIF2的鸟嘌呤核苷酸交换因子，它将eIF2从GDP转化为能够进行翻译起始的GTP结合形式。强制降解依赖性对照靶向该eIF2B再循环步骤，允许对全局基因表达谱进行重编程。此外，人类疾病，白色物质消失的白质脑病（VWM），是由eIF 2 B亚基基因突变引起的。最近，我们已经发现eIF2B鸟嘌呤核苷酸交换因子驻留在一个特定的细胞质焦点在酵母，酿酒酵母。eIF2B是这个焦点的常驻特征，而eIF2来回穿梭。此外，eIF2穿梭的体内速率与鸟嘌呤核苷酸交换活性的变化相关，这表明该大细胞质焦点是鸟嘌呤核苷酸交换的位点。从这个角度来看，我们讨论这些发现在更广泛的背景下的鸟嘌呤核苷酸交换因子的分类。
The eukaryotic initiation factor 2B (eIF2B) serves an essential recycling function in protein synthesis. As the guanine nucleotide exchange factor for eIF2, it recycles eIF2 from a GDP to a GTP bound form that is competent for translation initiation. Stress-dependent controls target this eIF2B-recycling step allowing a reprogramming of the global gene expression profile. In addition, a human disease, leukoencephalopathy with vanishing white matter (VWM), is caused by mutations in the eIF2B subunit genes. Recently, we have found that the eIF2B guanine nucleotide exchange factor resides in a specific cytoplasmic focus in the yeast, Saccharmoyces cerevisiae. eIF2B is a resident feature of this focus, whereas eIF2 shuttles to and fro. Moreover, the in vivo rate of eIF2 shuttling correlates with changes in guanine nucleotide exchange activity implicating this large cytoplasmic focus as a site of guanine nucleotide exchange. In this perspective, we discuss these findings in the wider context of the assortment of guanine nucleotide exchange factors.