摘要
During eukaryotic transcription,the nascent RNA molecules are processed and packed into RNA-protein particles,termed messenger ribonucleoparticles(mRNPs)[1].Precise mRNP assembly is essential for efficient messenger RNA(mRNA)processing and export[2].A conserved protein complex called TREX(transcription export complex)plays an important role in mRNP biogenesis[3-6].
在真核生物转录过程中,新生成的RNA分子的成熟需要众多蛋白质的参与.其中,酿酒酵母THO复合物能够与转录活跃的染色质区域相结合,通过招募依赖于RNA的ATP水解酶Sub2,去除伴随转录过程形成的R-loop并促进m RNA的出核运输.本研究成功地在体外重构了酿酒酵母THO复合物,并运用单颗粒冷冻电镜技术分别解析了单独的THO复合物及其与Sub2结合状态下的近原子分辨率结构.在此结构的基础上,本研究通过突变关键氨基酸位点破坏THO和Sub2之间的相互作用,揭示了THO复合物招募Sub2的分子机制.此外,本研究结合分子动力学模拟、染色质免疫沉淀和免疫荧光等技术手段,阐述了THO-Sub2复合物防止转录过程中R-loop结构的积累以及确保基因组稳定性和促进m RNA出核的分子机制.
作者
Cong Chen
Ming Tan
Zhenfang Wu
Yuebin Zhang
Fanyang He
Yanjia Lu
Shaobai Li
Mi Cao
Guohui Li
Jian Wu
Hong Cheng
Ming Lei
陈聪;谭明;吴振芳;张跃斌;贺钒洋;鲁彦伽;李少白;曹密;李国辉;武健;程红;雷鸣(State Key Laboratory of Oncogenes and Related Genes,Ninth People's Hospital,Shanghai Jiao Tong University School of Medicine,Shanghai 200011,China;Shanghai Institute of Precision Medicine,Shanghai 200125,China;Laboratory of Molecular Modeling and Design,State Key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China;State Key Laboratory of Molecular Biology,CAS Center for Excellence in Molecular Cell Science,Shanghai Institute of Biochemistry and Cell Biology,Chinese Academy of Sciences,Shanghai 200031,China;Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education,Shanghai Jiao Tong University School of Medicine,Shanghai 200025,China)
基金
supported by grants from the National Key R&D Program of China (2017YFA0504400 to Hong Cheng and 2019YFA0709400 to Guohui Li)
the National Natural Science Foundation of China (31525007 and 31930063 to Ming Lei, 31925008 and 31770880 to Hong Cheng, 32071189 to Jian Wu, and 21625302, 21933010, and 31700647 to Guohui Li)
the Strategic Priority Research Program of Chinese Academy of Sciences (XDB19000000 to Hong Cheng)
the Shanghai Municipal Education Commission—Gaofeng Clinical Medicine Grant Support (20181711 to Jian Wu)。
