Eukaryotic peptide chain release factor 1 participates in translation termination of specific cysteine-poor prolamines in rice endosperm
Eukaryotic peptide chain release factor 1 participates in translation termination of specific cysteine-poor prolamines in rice endosperm
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DOI：
10.1016/j.plantsci.2018.12.006
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发表时间：
2019-04-01
期刊：
影响因子：
5.2
通讯作者：
Kumamaru, Toshihiro
中科院分区：
文献类型：
--
作者：
Elakhdar, Ammar;Ushijima, Tomokazu;Kumamaru, Toshihiro
醇溶谷蛋白是醇溶性蛋白质，根据它们是否可以分别在没有还原剂或有还原剂的情况下醇提取而被分类为半胱氨酸贫乏（CysP）或半胱氨酸富集（CysR）。在水稻esp 1突变体，各种CysP醇溶蛋白表现出减少和正常量的等电聚焦带，表明突变只影响某些醇溶蛋白类。为了研究CysP醇溶蛋白合成和积累的遗传调控，我们构建了ESP 1的高分辨率遗传连锁图谱。ESP 1基因定位在水稻第7染色体上的20 kb区域内。在这个区域的注释基因的测序分析揭示了真核生物的肽链释放因子（eRF 1），参与终止密码子识别和翻译过程中从核糖体的起始多肽释放的单核苷酸多态性。随后的互补测试显示ESP 1编码eRF 1。我们还确定了UAA作为终止密码子的CysP醇溶谷蛋白与esp 1突变体中的浓度降低。识别试验和微阵列分析证实ESP 1/eRF 1识别UAA/UAG，但不识别UGA。我们的研究结果提供了令人信服的证据表明，ESP 1/eul参与在种子发育过程中的CysP醇溶蛋白的翻译终止。
Prolamines are alcohol-soluble proteins classified as either cysteine-poor (CysP) or cysteine-rich (CysR) based on whether they can be alcohol-extracted without or with reducing agents, respectively. In rice esp1 mutants, various CysP prolamines exhibit both reduced and normal amounts of isoelectric focusing bands, indicating that the mutation affects only certain prolamine classes. To examine the genetic regulation of CysP prolamine synthesis and accumulation, we constructed a high-resolution genetic linkage map of ESP1. The ESP1 gene was mapped to within a 20 kb region on rice chromosome 7. Sequencing analysis of annotated genes in this region revealed a single-nucleotide polymorphism within eukaryotic peptide chain release factor (eRF1), which participates in stop-codon recognition and nascent-polypeptide release from ribosomes during translation. A subsequent complementation test revealed that ESP1 encodes eRF1. We also identified UAA as the stop codon of CysP prolamines with reduced concentration in esp1 mutants. Recognition assays and microarray analysis confirmed that ESP1/eRF1 recognizes UAA/UAG, but not UGA. Our results provide convincing evidence that ESP1/eul participates in the translation termination of CysP prolamines during seed development.