重要疾病或基礎細胞生命活動相關的新生物化學機制探索與研究

邵峰

摘 要：該研究在基因組、RNA和蛋白質3個水平對新生物化學機制展開探索和深入研究。第一個內容研究致病菌效應分子和宿主分子作用的生化機理。選擇病原細菌的毒力效應蛋白在進入真核宿主細胞后的所發揮的功能為對象，重點研究來自引起腹瀉的志賀氏痢疾桿菌和導致肺炎的軍團桿菌的一系列重要效應蛋白分子的功能，查找它們在宿主細胞體內的靶蛋白分子，進而闡明它們各自對其宿主靶蛋白功能抑制的生物化學機理和結構基礎，最終了解這兩種致病菌的致病的分子生物化學機理。第二個內容是真核生物中RNA降解的激活機理。外切體（Exosome）是RNA降解的分子機器，在細胞核內它需要多腺苷聚合酶TRAMP復合體的激活，在細胞質內它需要SKI復合體的共同作用。我們希望以出芽酵母作為模式生物，通過結構生物學的手段解析TRAMP以及SKI復合物的晶體結構，并結合體外生化實驗以及體內突變實驗揭示TRAMP和SKI復合物激活外切體降解底物RNA的分子機制。第三個內容研究R-loop結構影響基因組穩定性的生化機理。研究發現，DNA轉錄過程中，新生RNA與模板DNA分子之間配對形成異常的RNA：DNA雜交分子（又稱R-loop結構）可以導致基因組非穩性及相關疾病的發生。基于這個全新的發現，研究將運用遺傳學、細胞生物學、分子生物學和生物化學等多種方法進一步闡明R-loop結構及新生RNA影響基因組穩定性的生物化學機制，從而在此基礎上設計方法來干擾和避免R-loop結構形成，為相關基因組非穩性疾病的預防和治療提供理論基礎和可能性。另外，第四個內容將建立生物信息學平臺，服務于研究所不斷增長的科學運算和科研信息管理、分析和應用等方面的需求。

關鍵詞：新生物化學機制 重要疾病 基礎生命活動 病原菌 致病分子機理 RNA降解 結構生物學 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

閱讀全文鏈接（需實名注冊）：http：//www.nstrs.cn/xiangxiBG.aspx？id=34128&flag=1