Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, Regensburg, Germany.
J Exp Bot. 2019 Aug 7;70(15):3757-3763. doi: 10.1093/jxb/erz173.
In eukaryotes, the regulated transport of mRNAs from the cell nucleus to the cytosol is a critical step in the expression of protein-coding genes, as it links nuclear mRNA synthesis with cytosolic translation. The pre-mRNAs that are synthesised by RNA polymerase II are processed by 5´-capping, splicing, and 3´-polyadenylation. The multi-subunit THO/TREX complex integrates mRNA biogenesis with their nucleocytosolic transport. Various export factors are recruited to the mRNAs during their maturation, which occurs essentially co-transcriptionally. These RNA-bound export factors ensure efficient transport of the export-competent mRNAs through nuclear pore complexes. In recent years, several factors involved in plant mRNA export have been functionally characterised. Analysis of mutant plants has demonstrated that impaired mRNA export causes defects in growth and development. Moreover, there is accumulating evidence that mRNA export can influence processes such as plant immunity, circadian regulation, and stress responses. Therefore, it is important to learn more details about the mechanism of nucleocytosolic mRNA transport in plants and its physiological significance.
在真核生物中，从细胞核到细胞质的 mRNA 的调控运输是蛋白质编码基因表达的关键步骤，因为它将核 mRNA 合成与细胞质翻译联系起来。由 RNA 聚合酶 II 合成的前体 mRNA 经过 5' 端加帽、剪接和 3' 端多聚腺苷酸化处理。多亚基 THO/TREX 复合物将 mRNA 的生物发生与其核质运输整合在一起。在其成熟过程中，各种输出因子被募集到 mRNA 上，这一过程基本上是转录共进行的。这些与 RNA 结合的输出因子确保了具有输出能力的 mRNA 通过核孔复合物的有效运输。近年来，已对几种参与植物 mRNA 输出的因子进行了功能表征。对突变体植物的分析表明，mRNA 输出受损会导致生长和发育缺陷。此外，越来越多的证据表明，mRNA 输出可以影响植物免疫、昼夜节律调节和应激反应等过程。因此，了解植物核质间 mRNA 运输的机制及其生理意义的更多细节非常重要。
