In eukaryotes, most RNA molecules are exported into the cytoplasm after transcription. Long noncoding RNAs (lncRNAs) reside and function primarily inside the nucleus, but nuclear localization of mRNAs has been considered rare in both animals and plants. Here we show that Arabidopsis anaphase-promoting complex/cyclosome (APC/C) coactivator genes CDC20 and CCS52B (CDH1 ortholog) are co-expressed with their target cyclin B genes (CYCBs) during mitosis. CYCB transcripts can be exported and translated; however, CDC20 and CCS52B mRNAs are confined to the nucleus at prophase, and the cognate proteins are not translated until the redistribution of the mRNAs to the cytoplasm after nuclear envelope breakdown (NEBD) at prometaphase. The 5′ untranslated region (UTR) plays dual roles in CDC20 mRNA nuclear localization and translation. Mitotic accumulation of CDC20 and CCS52B transcripts enables the timely and rapid activation of APC/C, while the nuclear sequestration of these transcripts at prophase appears to protect cyclins from precocious degradation.

在真核生物中，大多数 RNA 分子在转录后被输出到细胞质中。长链非编码 RNA (lncRNA) 主要存在于细胞核内并发挥作用，但 mRNA 的核定位在动物和植物中都被认为是罕见的。在这里，我们显示拟南芥后期促进复合物/细胞周期体 (APC/C) 共激活因子基因CDC20和CCS52B（CDH1直系同源物）在有丝分裂期间与其靶细胞周期蛋白 B基因 ( CYCB )共表达。CYCB成绩单可导出翻译；然而，CDC20和CCS52BmRNA 在前期被限制在细胞核中，直到在前中期核膜破裂 (NEBD) 后 mRNA 重新分布到细胞质中，同源蛋白才被翻译。5' 非翻译区 (UTR) 在CDC20 mRNA 核定位和翻译中起着双重作用。CDC20和CCS52B转录物的有丝分裂积累能够及时快速地激活 APC/C，而这些转录物在前期的核隔离似乎可以保护细胞周期蛋白免受早熟降解。