The RNA helicase, eIF4A-1, is required for ovule development and cell size homeostasis in Arabidopsis.
The RNA helicase, eIF4A-1, is required for ovule development and cell size homeostasis in Arabidopsis.
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DOI：
10.1111/tpj.13062
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发表时间：
2015-12
期刊：
影响因子：
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通讯作者：
Doonan JH
中科院分区：
文献类型：
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作者：
Bush MS;Crowe N;Zheng T;Doonan JH
eIF4A 是一种高度保守的 RNA 刺激的 ATP 酶和解旋酶，参与 mRNA 翻译的起始。拟南芥基因组编码两种亚型，其中一种 (eIF4A-1) 是协调细胞周期进程和细胞大小所必需的。 T-DNA 突变体 eif4a1 系的 eIF4A 蛋白水平降低，表现出生长缓慢、侧根形成减少、开花延迟和胚珠发育异常。 eIF4A-1 的缺失会降低根分生组织中有丝分裂细胞的比例，并扰乱细胞大小和细胞周期进程之间的关系。几种细胞周期报告蛋白，特别是那些在 G2/M 表达的蛋白，在 eif4a1 突变分生组织中表达减少。单个 eif4a1 突变体是半不育的，并且显示出异常的胚珠生长，而双 eif4a1 eif4a2 纯合突变体无法恢复，表明 eIF4A 功能对于植物生长和发育至关重要。虽然细胞周期进程和发育中的转录控制机制已被广泛剖析，但人们对翻译的作用知之甚少。在这里，我们发现翻译起始因子 eIF4A 水平降低的拟南芥 TDNA 突变体表现出多种生长缺陷，表明 eIF4A-1 是正常细胞周期进程以及细胞分裂与细胞生长协调所必需的。
eIF4A is a highly conserved RNA‐stimulated ATPase and helicase involved in the initiation of mRNA translation. The Arabidopsis genome encodes two isoforms, one of which (eIF4A‐1) is required for the coordination between cell cycle progression and cell size. A T‐DNA mutant eif4a1 line, with reduced eIF4A protein levels, displays slow growth, reduced lateral root formation, delayed flowering and abnormal ovule development. Loss of eIF4A‐1 reduces the proportion of mitotic cells in the root meristem and perturbs the relationship between cell size and cell cycle progression. Several cell cycle reporter proteins, particularly those expressed at G2/M, have reduced expression in eif4a1 mutant meristems. Single eif4a1 mutants are semisterile and show aberrant ovule growth, whereas double eif4a1 eif4a2 homozygous mutants could not be recovered, indicating that eIF4A function is essential for plant growth and development. While transcriptional control mechanisms in cell cycle progression and development have been extensively dissected, less is known about the role of translation. Here we show that an Arabidopsis TDNA mutant with reduced levels of the translation initiation factor eIF4A exhibits several growth defects suggesting that eIF4A‐1 is required for normal cell cycle progression and coordination of cell division with cell growth.