重要疾病或基础细胞生命活动相关的新生物化学机制探索与研究

摘 要：该研究在基因组、RNA和蛋白质3个水平对新生物化学机制展开探索和深入研究。第一个内容研究致病菌效应分子和宿主分子作用的生化机理。选择病原细菌的毒力效应蛋白在进入真核宿主细胞后的所发挥的功能为对象，重点研究来自引起腹泻的志贺氏痢疾杆菌和导致肺炎的军团杆菌的一系列重要效应蛋白分子的功能，查找它们在宿主细胞体内的靶蛋白分子，进而阐明它们各自对其宿主靶蛋白功能抑制的生物化学机理和结构基础，最终了解这两种致病菌的致病的分子生物化学机理。第二个内容是真核生物中RNA降解的激活机理。外切体（Exosome）是RNA降解的分子机器，在细胞核内它需要多腺苷聚合酶TRAMP复合体的激活，在细胞质内它需要SKI复合体的共同作用。我们希望以出芽酵母作为模式生物，通过结构生物学的手段解析TRAMP以及SKI复合物的晶体结构，并结合体外生化实验以及体内突变实验揭示TRAMP和SKI复合物激活外切体降解底物RNA的分子机制。第三个内容研究R-loop结构影响基因组稳定性的生化机理。研究发现，DNA转录过程中，新生RNA与模板DNA分子之间配对形成异常的RNA：DNA杂交分子（又称R-loop结构）可以导致基因组非稳性及相关疾病的发生。基于这个全新的发现，研究将运用遗传学、细胞生物学、分子生物学和生物化学等多种方法进一步阐明R-loop结构及新生RNA影响基因组稳定性的生物化学机制，从而在此基础上设计方法来干扰和避免R-loop结构形成，为相关基因组非稳性疾病的预防和治疗提供理论基础和可能性。另外，第四个内容将建立生物信息学平台，服务于研究所不断增长的科学运算和科研信息管理、分析和应用等方面的需求。

关键词：新生物化学机制 重要疾病 基础生命活动 病原菌 致病分子机理 RNA降解 结构生物学 R-loop

General Report for the Exploration of Critical Diseases/basic Cellular activities Related Biochemichal Mechanisms

Shao Feng

（National Institute of Biological Sciences， Beijing）

Abstract：Exploring new biochemical mechanisms greatly facilitates the understanding of vital activities and critical diseases， thus is of great significance in both basic science and application research. In this project， we study at DNA， RNA and protein levels. The first topic is about the interaction mechanism between bacterial effector protein and the host cells. Using Shigella and Legionella as the model， we are working to uncover some critical roles the bacterial effectors paly in modulating host cell activities， identify their target proteins and further elucidate the biochemical mechanism and structural basis of how the bacterial effectors inhibit their target protein activities. The second topic is the activation of eukaryotic RNA degradation. Exosome is the RNA degradation machine which has to be activated by the TRAMP complex in nucleus， and function together with SKI complex in cytoplasm. Using budding yeast as the model， we will resolve the crystal structure of TRAMP and SKI complexes. The molecular mechanism under which TRAMP and SKI complexes activate the RNA-degrading function of exosome will be futher revealed through biochemical experients and site mutations. The third topic is the biochemical mechanism under which R-loop structure affects genemoe stability. Previoiusly we found that newly-synthesized RNA pairs up with template DNA to form abnormal DNA-RNA hybrid （or R-loop） during transcription. Based on this novel phenomema， genetics， cellular biology， molecular biology and biochemistry methods will be applied to further clarify the role of R-loop and newly-synthesized RNA in affecting genome stability. New methods will be designed accordingly to interfere with the RNA-loop formation， providing theoretical foundation and potentialbility for the prevention and treatment of genome-instability related diseases. Finally， the fourth topic is about building a bioinformatics platform within the institute to fulfill the growing demand for scientific computation， statistical analysis and application. Study of the above four topics will provide unique perspective in understanding some novel biochemical mechanisms of critical diseases or basic cellular activities.

Key Words：Novel biochemical mechanisms； Critical diseases； Vital activities； Pathogen； Molecular mechanism of pathogenesis； RNA degradation； Structural biology； R-loop

阅读全文链接（需实名注册）：http：///xiangxiBG.aspx？id=34128&flag=1