Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Mol Cell. 2020 Dec 17;80(6):1078-1091.e6. doi: 10.1016/j.molcel.2020.11.041. Epub 2020 Nov 27.
We report that the SARS-CoV-2 nucleocapsid protein (N-protein) undergoes liquid-liquid phase separation (LLPS) with viral RNA. N-protein condenses with specific RNA genomic elements under physiological buffer conditions and condensation is enhanced at human body temperatures (33°C and 37°C) and reduced at room temperature (22°C). RNA sequence and structure in specific genomic regions regulate N-protein condensation while other genomic regions promote condensate dissolution, potentially preventing aggregation of the large genome. At low concentrations, N-protein preferentially crosslinks to specific regions characterized by single-stranded RNA flanked by structured elements and these features specify the location, number, and strength of N-protein binding sites (valency). Liquid-like N-protein condensates form in mammalian cells in a concentration-dependent manner and can be altered by small molecules. Condensation of N-protein is RNA sequence and structure specific, sensitive to human body temperature, and manipulatable with small molecules, and therefore presents a screenable process for identifying antiviral compounds effective against SARS-CoV-2.
我们报告称，SARS-CoV-2 的核衣壳蛋白（N 蛋白）与病毒 RNA 发生液-液相分离（LLPS）。在生理缓冲条件下，N 蛋白与特定的 RNA 基因组元件凝聚，在人体温度（33°C 和 37°C）下凝聚增强，在室温（22°C）下减弱。特定基因组区域的 RNA 序列和结构调节 N 蛋白的凝聚，而其他基因组区域则促进凝聚物的溶解，从而可能防止大基因组的聚集。在低浓度下，N 蛋白优先交联到具有特定特征的区域，这些特征包括由结构元件包围的单链 RNA，这些特征指定了 N 蛋白结合位点（价数）的位置、数量和强度。N 蛋白的液态凝聚物以浓度依赖的方式在哺乳动物细胞中形成，并且可以被小分子改变。N 蛋白的凝聚是 RNA 序列和结构特异性的，对人体温度敏感，并且可以用小分子操纵，因此为筛选针对 SARS-CoV-2 的有效抗病毒化合物提供了一个可筛选的过程。
