Torsin ATPase deficiency leads to defects in nuclear pore biogenesis and sequestration of MLF2
Torsin ATPase deficiency leads to defects in nuclear pore biogenesis and sequestration of MLF2
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DOI：
10.1083/jcb.201910185
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发表时间：
2020-06-01
影响因子：
7.8
通讯作者：
Schlieker, Christian
中科院分区：
文献类型：
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作者：
Rampello, Anthony J.;Laudermilch, Ethan;Schlieker, Christian
含有FG-核孔蛋白和泛素的核膜突出（泡）是扭转蛋白ATP酶操纵的表型标志。起泡的动力学和与核孔生物发生的联系仍然知之甚少。我们采用基于蛋白质组学的方法来鉴定骨髓白血病因子2（MLF 2）作为水泡的腔成分。使用基于MLF 2的活细胞成像平台，我们证明了在有丝分裂期间核膜重组后立即快速同步地发生核膜起泡。水泡的形成是独立的泛蛋白共轭水泡内，但严格依赖于POM 121，一个跨膜核孔蛋白的间期核孔生物发生所必需的。Nup 358是间期核孔复合物（NPC）生物发生的晚期标志物，相对于Torsin缺陷细胞核膜中的FG-核孔蛋白，其代表性不足。水泡形成的动力学，其对POM 121的依赖性，以及扭转蛋白缺陷细胞中成熟NPC的减少，使我们得出结论，扭转蛋白操纵的标志性表型代表异常NPC中间体。
Nuclear envelope herniations (blebs) containing FG-nucleoporins and ubiquitin are the phenotypic hallmark of Torsin ATPase manipulation. Both the dynamics of blebbing and the connection to nuclear pore biogenesis remain poorly understood. We employ a proteomics-based approach to identify myeloid leukemia factor 2 (MLF2) as a luminal component of the bleb. Using an MLF2-based live-cell imaging platform, we demonstrate that nuclear envelope blebbing occurs rapidly and synchronously immediately after nuclear envelope reformation during mitosis. Bleb formation is independent of ubiquitin conjugation within the bleb, but strictly dependent on POM121, a transmembrane nucleoporin essential for interphase nuclear pore biogenesis. Nup358, a late marker for interphase nuclear pore complex (NPC) biogenesis, is underrepresented relative to FG-nucleoporins in nuclear envelopes of Torsin-deficient cells. The kinetics of bleb formation, its dependence on POM121, and a reduction of mature NPCs in Torsin-deficient cells lead us to conclude that the hallmark phenotype of Torsin manipulation represents aberrant NPC intermediates.