中国科学院上海生化细胞所陈玲玲和刘珈泉研究组合作取得最新进展。他们发现长链非编码 RNA (lncRNA) SLERT 控制纤维中心 (FC) / 致密纤维成分 (DFC) 的相分离以促进 RNA 聚合酶 I (Pol I)转录。相关论文于2021年7月30日发表在《科学》杂志上。

他们报告了单个球形 FC / DFC 单元在人类细胞中被 DEAD-box RNA 解旋酶 DDX21 包被。 LncRNA SLERT 与 DDX21 RecA 结构域结合，以促进 DDX21在亚化学计量比水平采用封闭构象，通过分子伴侣样机制，导致形成包被 DFC 的低多聚和松散 DDX21 簇，这是适当的 FC / DFC 流动性和 Pol I 处理能力所需。他们的结果表明，SLERT 是一种 RNA 调控子，可控制 FC/DFC 的生物物理特性，从而控制核糖体 RNA 的产生。

研究人员表示，Pol I转录发生在核仁中的FC和DFC的边界。

附：英文原文

Title: lncRNA SLERT controls phase separation of FC/DFCs to facilitate Pol I transcription

Author: Man Wu, Guang Xu, Chong Han, Peng-Fei Luan, Yu-Hang Xing, Fang Nan, Liang-Zhong Yang, Youkui Huang, Zheng-Hu Yang, Lin Shan, Li Yang, Jiaquan Liu, Ling-Ling Chen

Issue&Volume: 2021/07/30

Abstract: RNA polymerase I (Pol I) transcription takes place at the border of the fibrillar center (FC) and the dense fibrillar component (DFC) in the nucleolus. Here, we report that individual spherical FC/DFC units are coated by the DEAD-box RNA helicase DDX21 in human cells. The long noncoding RNA (lncRNA) SLERT binds to DDX21 RecA domains to promote DDX21 to adopt a closed conformation at a substoichiometric ratio through a molecular chaperone–like mechanism resulting in the formation of hypomultimerized and loose DDX21 clusters that coat DFCs, which is required for proper FC/DFC liquidity and Pol I processivity. Our results suggest that SLERT is an RNA regulator that controls the biophysical properties of FC/DFCs and thus ribosomal RNA production.

DOI: 10.1126/science.abf6582

Source: https://science.sciencemag.org/content/373/6554/547