真核生物mRNA转录出核复合物TREX-1的结构与功能研究

Eukaryotic mRNA TRanscription/EXport complex-1 (TREX-1 complex) is evolutionarily conserved multi-protein complex from yeast to human, participating in mRNA transcription, post-transcription processing and export. Previous report indicated that different protein component of TREX-1 complex has dysregulated expressed in different cancer specimens. Yeast TREX-1 complex consists Sub2, Yra1 and THO complex, while human TREX-1 complex consists Uap56 (yeast Sub2 homologous protein), Aly (yeast Yra1 homologous protein) and human THO complex. The detail mechanism of how TREX-1 complex participate pre-mRNA maturation and export is still obscurity, due to the miss of high-resolution 3D structural model of TREX-1 complex. In previous study, we get highly purified yeast THO complex through recombinant baculovirus expression system. Based on these, we try to reconstitute yeast and human TREX-1 complex in vivo and in vitro, through protein X-ray crystallography and cyro-EM technology, aim to get high-resolution 3D structure of TREX-1 complex. We also try to use biochemical and cell biology method to investigate the molecular mechanism of TREX-1 assembling and its participation mRNA export.

真核生物mRNA转录出核复合物TREX-1广泛存在于从酵母到哺乳动物中，参与mRNA的转录、转录后加工和出核运输等一系列过程。有报道指出，TREX-1复合物组分在很多癌症组织中检测到表达异常。TREX-1复合物在真核生物中保守性较高，酵母源TREX-1复合物由Sub2、Yra1和THO复合物组成，人源TREX-1复合物由Uap56、Yra1以及人源THO复合物组成。目前，缺乏TREX-1复合物的高分辨率三维结构，这极大的阻碍了对其参与pre-mRNA加工分子机理的深入研究。我们之前的研究通过昆虫杆状病毒体外重组表达获得了高纯度的酵母源THO复合物。在此基础上，本项目拟对酵母和人源的TREX-1复合物进行组装与纯化，通过结合蛋白质X射线晶体学和冷冻电镜技术，以期获得TREX-1复合物高分辨率三维结构，并辅以生物化学和细胞生物学技术，研究其组装及参与mRNA出核的分子机制。