Fang Yiling, Tang Yu, Xie Peiqiao, Hsieh Kendall, Nam Heejae, Jia Min, Reyes Andres V, Liu Yuchen, Xu Shouling, Xu Xiaosa, Gu Yangnan
Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA.
Department of Biology and Carnegie Mass Spectrometry Facility, Carnegie Institution for Science, Stanford, CA, USA.
Nat Plants. 2025 Feb;11(2):295-308. doi: 10.1038/s41477-025-01908-y. Epub 2025 Jan 31.
The nuclear pore complex (NPC) is a cornerstone of eukaryotic cell functionality, orchestrating the nucleocytoplasmic shuttling of macromolecules. Here we report that Plant Nuclear Envelope Transmembrane 1 (PNET1), a transmembrane nucleoporin, is an adaptable NPC component that is mainly expressed in actively dividing cells. PNET1's selective incorporation into the NPC is required for rapid cell growth in highly proliferative meristem and callus tissues in Arabidopsis. We demonstrate that the cell cycle-dependent phosphorylation of PNET1 coordinates mitotic disassembly and post-mitotic reassembly of NPCs during the cell cycle. PNET1 hyperphosphorylation disrupts its interaction with the NPC scaffold, facilitating NPC dismantling and nuclear membrane breakdown to trigger mitosis. In contrast, nascent, unphosphorylated PNET1 is incorporated into the nuclear pore membrane in the daughter cells, where it restores interactions with scaffolding nucleoporins for NPC reassembly. The expression of the human PNET1 homologue is required for and markedly upregulated during cancer cell growth, suggesting that PNET1 plays a conserved role in facilitating rapid cell division during open mitosis in highly proliferative tissues.
核孔复合体（NPC）是真核细胞功能的基石，协调大分子的核质穿梭。在此，我们报道植物核膜跨膜蛋白1（PNET1），一种跨膜核孔蛋白，是一种适应性的NPC组分，主要在活跃分裂的细胞中表达。在拟南芥高度增殖的分生组织和愈伤组织中，PNET1选择性地整合到NPC中是细胞快速生长所必需的。我们证明，PNET1的细胞周期依赖性磷酸化在细胞周期中协调NPC的有丝分裂解体和有丝分裂后重新组装。PNET1的过度磷酸化破坏了它与NPC支架的相互作用，促进NPC解体和核膜破裂以触发有丝分裂。相反，新生的、未磷酸化的PNET1在子细胞中被整合到核孔膜中，在那里它恢复与支架核孔蛋白的相互作用以进行NPC重新组装。人类PNET1同源物的表达在癌细胞生长过程中是必需的且显著上调，这表明PNET1在促进高度增殖组织中开放有丝分裂期间的快速细胞分裂中发挥保守作用。
