Proline responding1 Plays a Critical Role in Regulating General Protein Synthesis and the Cell Cycle in Maize[C][W][OPEN]
Proline responding1 Plays a Critical Role in Regulating General Protein Synthesis and the Cell Cycle in Maize[C][W][OPEN]
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DOI：
10.1105/tpc.114.125559
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发表时间：
2014-06
期刊：
影响因子：
11.6
通讯作者：
G. Wang;Jushan Zhang;Guifeng Wang;Xiangyun Fan;Xin Sun;Hongli Qin;Nan Xu;Mingyu Zhong;
中科院分区：
文献类型：
--
作者：
G. Wang;Jushan Zhang;Guifeng Wang;Xiangyun Fan;Xin Sun;Hongli Qin;Nan Xu;Mingyu Zhong;
脯氨酸在植物细胞对环境胁迫的反应中起着重要作用，但其在生长发育中的潜在生物学功能尚未完全了解。对玉米种子突变体脯氨酸应答1（pro 1）基因的定位克隆和功能分析表明，脯氨酸在蛋白质合成和细胞周期转换中起调控作用。脯氨酸是一种重要的氨基酸，在许多植物中积累。脯氨酸除了在植物细胞对环境胁迫的反应中起作用外，其在生长发育中的潜在生物学功能尚不清楚。在这里，我们报告的玉米（玉米）经典突变体脯氨酸响应1（pro 1）基因的克隆和功能特性。该基因编码催化谷氨酸生物合成脯氨酸的Δ1-吡咯啉-5-羧酸合成酶。Pro 1功能的丧失显著抑制了Pro 1突变体中脯氨酸的生物合成并降低了其积累。脯氨酸缺乏导致不带电荷的tRNApro AGG积累水平增加，并触发pro 1突变体中真核起始因子2α（eIF 2 α）的磷酸化，导致该突变体中蛋白质合成的普遍减少。脯氨酸缺乏还在转录水平下调主要细胞周期蛋白基因，导致细胞周期停滞和细胞增殖抑制。这些过程是可逆的，当外部脯氨酸提供给突变体，表明脯氨酸在细胞周期转换中起着调节作用。总之，这些结果表明，脯氨酸在调节植物的一般蛋白质合成和细胞周期转换中起着重要作用。
Proline plays an important role in plant cell responses to environmental stresses, but its potential biological functions in growth and development are not fully understood. Positional cloning and functional characterization of the classical maize seed mutant proline responding1 (pro1) gene demonstrate that proline plays regulatory roles in general protein synthesis and the cell cycle transition. Proline, an important amino acid, accumulates in many plant species. Besides its role in plant cell responses to environmental stresses, the potential biological functions of proline in growth and development are unclear. Here, we report cloning and functional characterization of the maize (Zea mays) classic mutant proline responding1 (pro1) gene. This gene encodes a Δ1-pyrroline-5- carboxylate synthetase that catalyzes the biosynthesis of proline from glutamic acid. Loss of function of Pro1 significantly inhibits proline biosynthesis and decreases its accumulation in the pro1 mutant. Proline deficiency results in an increased level of uncharged tRNApro AGG accumulation and triggers the phosphorylation of eukaryotic initiation factor 2α (eIF2α) in the pro1 mutant, leading to a general reduction in protein synthesis in this mutant. Proline deficiency also downregulates major cyclin genes at the transcriptional level, causing cell cycle arrest and suppression of cell proliferation. These processes are reversible when external proline is supplied to the mutant, suggesting that proline plays a regulatory role in the cell cycle transition. Together, the results demonstrate that proline plays an important role in the regulation of general protein synthesis and the cell cycle transition in plants.