A Musashi-Related Protein is Essential for Gametogenesis in Arabidopsis
A Musashi-Related Protein is Essential for Gametogenesis in Arabidopsis
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DOI：
10.1101/579714
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发表时间：
2019-03
期刊：
影响因子：
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通讯作者：
Laura A. Moody;E. Rabbinowitsch;H. Dickinson;Roxaana Clayton;David M. Emms;J. Langdale
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作者：
Laura A. Moody;E. Rabbinowitsch;H. Dickinson;Roxaana Clayton;David M. Emms;J. Langdale
武藏(Musashi，MSI)蛋白是一组进化上保守的RNA结合蛋白，在动物许多重要的发育过程中，需要有针对性地控制mRNA的翻译。最值得注意的是，MSI蛋白在精子发生和卵子发生过程中都发挥着重要作用。MSI蛋白也存在于植物中，但这些蛋白在很大程度上还没有确定。在这里，我们报道了拟南芥MSI同源败育配子体2(AOG2)的功能特征，它编码一个含有两个RNA识别基序和一个内质网靶向信号的蛋白质。在瞬时分析中，AOG2-GFP翻译融合定位于内质网，表明AOG2很可能与内质网靶向的mRNAs结合。我们发现，AOG2功能的紊乱会导致胚珠和种子的高败育率，而功能突变的纯合缺失会导致胚胎死亡。此外，我们证明了AOG2在花粉有丝分裂I过程中需要建立不对称性，而AOG2功能的丧失会导致花粉活力的丧失。综上所述，这些结果表明，AOG2在拟南芥配子体发育过程中极性的建立和/或有丝分裂的进行中是必需的，因此MSI相关蛋白在动植物配子发生中都具有进化上保守的作用。意义声明败育配子体2(AOG2)编码拟南芥配子发生和胚胎发生所必需的与舞水相关的RNA结合蛋白。在拟南芥配子体发育过程中，AOG2是建立极性和/或有丝分裂进程所必需的，因此Musashi相关蛋白在动植物配子发生中都具有进化上保守的作用。
Musashi (Msi) proteins are an evolutionarily conserved group of RNA-binding proteins, required for targeted control of mRNA translation during many important developmental processes in animals. Most notably, Msi proteins play important roles during both spermatogenesis and oogenesis. Msi proteins also exist in plants but these are largely uncharacterized. Here we report the functional characterization of an Arabidopsis Msi ortholog ABORTED GAMETOPHYTE 2 (AOG2), which encodes a protein containing two RNA recognition motifs and an ER-targeting signal. AOG2-GFP translational fusions were localized to the ER in transient assays, suggesting that AOG2 most likely binds to ER-targeted mRNAs. We show that disrupted AOG2 function leads to a high rate of both ovule and seed abortion, and that homozygous loss of function mutants are embryo lethal. Furthermore, we demonstrate that AOG2 is required to establish asymmetry during pollen mitosis I, and that loss of AOG2 function leads to loss of pollen viability. Collectively the results reveal that AOG2 is required for the establishment of polarity and/or the progression of mitosis during gametophyte development in Arabidopsis, and thus Msi-related proteins have an evolutionarily conserved role in gametogenesis in both animals and plants. SIGNIFICANCE STATEMENT ABORTED GAMETOPHYTE 2 (AOG2) encodes a Musashi-related RNA-binding protein that is required for gametogenesis and embryogenesis in Arabidopsis. AOG2 is required for the establishment of polarity and/or the progression of mitosis during gametophyte development in Arabidopsis, and thus Musashi-related proteins have an evolutionarily conserved role in gametogenesis in both animals and plants.