G2 arrest and impaired nucleocytoplasmic transport in mouse embryos lacking the proto‐oncogene CAN/Nup214.
G2 arrest and impaired nucleocytoplasmic transport in mouse embryos lacking the proto‐oncogene CAN/Nup214.
复制标题
缺乏原癌基因 CAN/Nup214 的小鼠胚胎中，G2 细胞的核细胞质运输受到抑制和受损。
作者：
J. Deursen;J. Boer;L. Kasper;G. Grosveld
脊椎动物核孔复合体(NPC)是一个125-丙二醛多蛋白组合体，介导核质转运。它的一个成分，CaN/Nup214，是一种含有FXFG重复序列的蛋白，已知与人类髓系白血病有关。我们已经设计了一种强大的遗传学方法，使用小鼠零胚胎中的母源蛋白，以表明CaN/Nup214在体内对NPC功能是必不可少的。我们证明了Can−/−小鼠胚胎干细胞(ES)是不能存活的，并且−/−胚胎可以在性交后4.0d到4.5d之间死于宫内，因为它们的CaN从母体来源中耗尽了。在体外培养的3.5d的突变胚胎中，CaN的逐渐耗竭导致细胞周期停滞于G2期，最终导致胚泡崩溃，损害了NLS介导的蛋白质摄取和多腺化RNA的核积聚。值得注意的是，这些有缺陷的、耗尽CaN的胚胎在其核膜或NPC中没有表现出任何严重的形态异常。我们的数据表明，CaN对细胞周期进程至关重要，是核蛋白输入和mRNA输出所必需的。
The vertebrate nucleopore complex (NPC) is a 125 MDa multiprotein assembly that mediates nucleocytoplasmic transport. One of its components, CAN/Nup214, is an FXFG repeat‐containing protein known to be involved in myeloid leukemia in humans. We have devised a powerful genetic approach, using maternally derived protein in murine null embryos, to show that CAN/ Nup214 is essential for NPC function in vivo. We demonstrate that CAN−/− mouse embryonic stem (ES) cells are not viable and that CAN−/− embryos die in utero between 4.0 and 4.5 days postcoitum, following the depletion of their CAN from maternal sources. In 3.5‐day‐old mutant embryos, cultured in vitro, progressive depletion of CAN leads to cell cycle arrest in G2 phase, and eventually to blastocoel collapse, impaired NLS‐mediated protein uptake and nuclear accumulation of polyadenylated RNA. Remarkably, these defective CAN‐depleted embryos do not display any gross morphological abnormalities in their nuclear envelopes or NPCs. Our data suggest that CAN is critical to cell cycle progression and required for both nuclear protein import and mRNA export.