Mutations in eIF5B Confer Thermosensitive and Pleiotropic Phenotypes via Translation Defects in Arabidopsis thaliana
Mutations in eIF5B Confer Thermosensitive and Pleiotropic Phenotypes via Translation Defects in Arabidopsis thaliana
复制标题
eIF5B 突变通过翻译缺陷赋予拟南芥热敏性和多效性表型
DOI：
10.1105/tpc.16.00808
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发表时间：
2017
期刊：
影响因子：
11.6
通讯作者：
Vierling Elizabeth
中科院分区：
文献类型：
--
作者：
Zhang Liyuan;Liu Xinye;Gaikwad Kishor;Kou Xiaoxia;Wang Fei;Tian Xuejun;Xin Mingming;Ni Zhongfu;Sun Qixin;Peng Huiru;Vierling Elizabeth
保守的真核生物翻译起始因子5 B，eIF 5 B，是一种在翻译起始后期起作用的GT3。我们发现一个对高温敏感的拟南芥突变体3（hot 3 -1）在没有胁迫的情况下表现为野生型，但不能适应高温，它在eIF 5 B1基因（At 1g 76810）上携带错义突变，产生温度敏感蛋白。更严重的是，T-DNA插入等位基因（hot 3 -2）导致多效性发育表型。令人惊讶的是，拟南芥有三个其他IF 5 B基因不取代IF 5 B1;其中两个似乎是在假基因化的过程中。对hot 3 - 1植物的多聚核糖体分析和RNA-seq分析表明，热胁迫后多聚核糖体的恢复延迟，一部分胁迫保护蛋白的翻译效率（TE）降低，表明翻译控制在热适应早期的关键作用。即使在最佳生长条件下，携带severehot 3 - 2等位基因的植物也显示出生长素调节基因、核糖体相关基因和电子传递基因的TE降低。热3 - 2数据表明，破坏核糖体上的特异性eIF 5 B相互作用可以直接或间接地差异影响翻译。因此，调节eIF 5 B相互作用可能是基因特异性翻译控制的另一种机制。
The conserved eukaryotic translation initiation factor 5B, eIF5B, is a GTPase that acts late in translation initiation. We found that anArabidopsis thalianamutant sensitive tohottemperatures 3 (hot3-1), which behaves as the wild type in the absence of stress but is unable to acclimate to high temperature, carries a missense mutation in theeIF5B1gene (At1g76810), producing a temperature sensitive protein. A more severe, T-DNA insertion allele (hot3-2) causes pleiotropic developmental phenotypes. Surprisingly, Arabidopsis has three othereIF5Bgenes that do not substitute foreIF5B1; two of these appear to be in the process of pseudogenization. Polysome profiling and RNA-seq analysis ofhot3-1plants show delayed recovery of polysomes after heat stress and reduced translational efficiency (TE) of a subset of stress protective proteins, demonstrating the critical role of translational control early in heat acclimation. Plants carrying the severehot3-2allele show decreased TE of auxin-regulated, ribosome-related, and electron transport genes, even under optimal growth conditions. Thehot3-2data suggest that disrupting specific eIF5B interactions on the ribosome can, directly or indirectly, differentially affect translation. Thus, modulating eIF5B interactions could be another mechanism of gene-specific translational control.