A role for the Saccharomyces cerevisiae ABCF protein New1 in translation termination/recycling
A role for the Saccharomyces cerevisiae ABCF protein New1 in translation termination/recycling
复制标题
DOI：
10.1093/nar/gkz600
复制
发表时间：
2019-09-19
影响因子：
14.9
通讯作者：
Hauryliuk, Vasili
中科院分区：
文献类型：
--
作者：
Kasari, Villu;Pochopien, Agnieszka A.;Hauryliuk, Vasili
翻译受许多辅助蛋白和翻译因子控制。在酿酒酵母中，翻译延伸需要一个必需的延伸因子，ABCF ATP酶eEF 3。一个密切相关的蛋白质，New 1，是由一个非必需基因编码的冷敏感性和核糖体组装缺陷敲除表型。由于New 1的确切分子功能是未知的，因此不清楚核糖体组装缺陷是直接的，即New 1是真正的组装因子，还是间接的，例如由于蛋白质合成中的缺陷。为了研究这一点，我们采用酵母遗传学，冷冻电子显微镜（cryo-EM）和核糖体分析（Ribo-Seq）来询问New 1的分子功能。New 1的过表达拯救了缺乏严格必需的翻译因子eEF 3的酵母菌株的活力。ATP酶缺陷型（EQ（2））New 1突变体锁定在80 S核糖体上的结构表明，New 1与eEF 3类似地与核糖体结合。最后，Ribo-Seq分析显示，New 1的缺失导致核糖体在3 '末端赖氨酸和精氨酸密码子的上游排队，包括编码细胞质翻译机制蛋白质的那些基因。我们的结果表明，New 1是一个翻译因子，可以微调翻译终止或核糖体回收的效率。
Translation is controlled by numerous accessory proteins and translation factors. In the yeast Saccharomyces cerevisiae, translation elongation requires an essential elongation factor, the ABCF ATPase eEF3. A closely related protein, New1, is encoded by a non-essential gene with cold sensitivity and ribosome assembly defect knock-out phenotypes. Since the exact molecular function of New1 is unknown, it is unclear if the ribosome assembly defect is direct, i.e. New1 is a bona fide assembly factor, or indirect, for instance due to a defect in protein synthesis. To investigate this, we employed yeast genetics, cryo-electron microscopy (cryo-EM) and ribosome profiling (Ribo-Seq) to interrogate the molecular function of New1. Overexpression of New1 rescues the inviability of a yeast strain lacking the otherwise strictly essential translation factor eEF3. The structure of the ATPase-deficient (EQ(2)) New1 mutant locked on the 80S ribosome reveals that New1 binds analogously to the ribosome as eEF3. Finally, Ribo-Seq analysis revealed that loss of New1 leads to ribosome queuing upstream of 3'-terminal lysine and arginine codons, including those genes encoding proteins of the cytoplasmic translational machinery. Our results suggest that New1 is a translation factor that fine-tunes the efficiency of translation termination or ribosome recycling.