小柯机器人

南方科技大学隋森芳团队揭示前体60S颗粒通过核孔复合体的核出口。这一研究成果于2023年5月31日在线发表在国际学术期刊《自然》上。

研究人员报告了被困在酵母核孔复合体（NPC）通道中的前体60S颗粒冷冻电镜结构。除了已知的组装因子外，结构中还包括多个具有输出功能的因子。这些因子一般与前体60S颗粒的柔性区域或亚单位界面结合，实际上形成了许多NPC结合的锚点。通过与NPC各种核蛋白的苯丙氨酸-甘氨酸（FG）重复序列的相互作用，这些因子共同促进前体60S颗粒通过NPC的中央FG重复网络。此外，对NPC内前体60S颗粒的轴向和径向分布的计算分析表明，一个NPC可以同时容纳多达四个前体60S颗粒，而且前体60S颗粒在靠近NPC壁的内环区域富集，其溶剂暴露的表面面向核孔的中心。这些数据表明，前体60S颗粒通过NPC的出口有一个易位模型。

据介绍，NPC是介导大分子或其组合物在细胞核和细胞质之间交换的双向门。核糖体亚单位的组装中间物，前体60S和前体40S颗粒，是NPC最大的货物之一，这些巨大的核糖核蛋白的输出需要许多输出因子。

附：英文原文

Title: Nuclear export of pre-60S particles through the nuclear pore complex

Author: Li, Zongqiang, Chen, Shuaijiabin, Zhao, Liang, Huang, Guoqiang, Xu, Huiqin, Yang, Xiaoyun, Wang, Peiyi, Gao, Ning, Sui, Sen-Fang

Issue&Volume: 2023-05-31

Abstract: The nuclear pore complex (NPC) is the bidirectional gate that mediates the exchange of macromolecules or their assemblies between nucleus and cytoplasm1,2,3. The assembly intermediates of the ribosomal subunits, pre-60S and pre-40S particles, are among the largest cargoes of the NPC and the export of these gigantic ribonucleoproteins requires numerous export factors4,5. Here we report the cryo-electron microscopy structure of native pre-60S particles trapped in the channel of yeast NPCs. In addition to known assembly factors, multiple factors with export functions are also included in the structure. These factors in general bind to either the flexible regions or subunit interface of the pre-60S particle, and virtually form many anchor sites for NPC binding. Through interactions with phenylalanine-glycine (FG) repeats from various nucleoporins of NPC, these factors collectively facilitate the passage of the pre-60S particle through the central FG repeat network of the NPC. Moreover, in silico analysis of the axial and radial distribution of pre-60S particles within the NPC shows that a single NPC can take up to four pre-60S particles simultaneously, and pre-60S particles are enriched in the inner ring regions close to the wall of the NPC with the solvent-exposed surface facing the centre of the nuclear pore. Our data suggest a translocation model for the export of pre-60S particles through the NPC.

DOI: 10.1038/s41586-023-06128-y

Source: https://www.nature.com/articles/s41586-023-06128-y

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
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