核孔复合物(NPC)介导所有大分子穿过核膜的运输。在具有开放有丝分裂的高等真核生物中,NPC在细胞周期的两个点组装:在有丝分裂晚期的核组装期间和在间期的核生长期间。NPC,真核细胞中最大的非聚合蛋白质复合物,细胞内的自我组装仍不清楚。最近的研究已经开始发现组装过程,越来越多的证据表明,有丝分裂后和间期NPC组装使用根本不同的机制;持续时间,结构中间体,分子参与者的调节是不同的,并且涉及不同类型的膜变形。在这篇评论中,我们总结了目前对这两种NPC组装模式的理解,并讨论了可能推动组装过程的结构和监管步骤。此外,我们将对NPC组装的理解与胚胎中快速核生长的机制相结合,最后,推测NPC的进化起源是由两种不同的组装机制的存在所暗示的。
The nuclear pore complex (NPC) mediates all macromolecular transport across the nuclear envelope. In higher eukaryotes that have an open mitosis, NPCs assemble at two points in the cell cycle: during nuclear assembly in late mitosis and during nuclear growth in interphase. How the NPC, the largest nonpolymeric protein complex in eukaryotic cells, self-assembles inside cells remained unclear. Recent studies have started to uncover the assembly process, and evidence has been accumulating that postmitotic and interphase NPC assembly use fundamentally different mechanisms; the duration, structural intermediates, and regulation by molecular players are different and different types of membrane deformation are involved. In this Review, we summarize the current understanding of these two modes of NPC assembly and discuss the structural and regulatory steps that might drive the assembly processes. We furthermore integrate understanding of NPC assembly with the mechanisms for rapid nuclear growth in embryos and, finally, speculate on the evolutionary origin of the NPC implied by the presence of two distinct assembly mechanisms.