Visualizing the nucleoplasmic maturation of human pre-60S ribosomal particles  

作　　者：Yunyang Zhang Xiaomeng Liang Sha Luo Yan Chen Yu Li Chengying Ma Ningning Li Ning Gao 

机构地区：[1]State Key Laboratory of Membrane Biology,Peking-Tsinghua Joint Center for Life Sciences,School of Life Sciences,Peking University,Beijing,China [2]Changping Laboratory,Beijing,China [3]National Biomedical Imaging Center,Peking University,Beijing,China

出　　处：《Cell Research》2023年第11期867-878,共12页细胞研究（英文版）

基　　金：supported by the National Natural Science Foundation of China (32230051 to N.G.,31922036 to N.L.);the National Key R&D Program of China (2019YFA0508904 to N.G.);the Qidong-SLS Innovation Fund to N.G.

摘　　要：Eukaryotic ribosome assembly is a highly orchestrated process that involves over two hundred protein factors.After early assembly events on nascent rRNA in the nucleolus,pre-60S particles undergo continuous maturation steps in the nucleoplasm,and prepare for nuclear export.Here,we report eleven cryo-EM structures of the nuclear pre-60S particles isolated from human cells through epitope-tagged GNL2,at resolutions of 2.8–4.3Å.These high-resolution snapshots provide fine details for several major structural remodeling events at a virtual temporal resolution.Two new human nuclear factors,L10K and C11orf98,were also identified.Comparative structural analyses reveal that many assembly factors act as successive place holders to control the timing of factor association/dissociation events.They display multi-phasic binding properties for different domains and generate complex binding inter-dependencies as a means to guide the rRNA maturation process towards its mature conformation.Overall,our data reveal that nuclear assembly of human pre-60S particles is generally hierarchical with short branch pathways,and a few factors display specific roles as rRNA chaperones by confining rRNA helices locally to facilitate their folding,such as the C-terminal domain of SDAD1.

关 键 词：DETAILS STEPS successive 

分 类 号：O57[理学—粒子物理与原子核物理]