重要疾病或基礎(chǔ)細胞生命活動相關(guān)的新生物化學(xué)機制探索與研究

邵峰

摘 要：該研究在基因組、RNA和蛋白質(zhì)3個水平對新生物化學(xué)機制展開探索和深入研究。第一個內(nèi)容研究致病菌效應(yīng)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(yīng)蛋白在進入真核宿主細胞后的所發(fā)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(dǎo)致肺炎的軍團桿菌的一系列重要效應(yīng)蛋白分子的功能，查找它們在宿主細胞體內(nèi)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(xué)機理和結(jié)構(gòu)基礎(chǔ)，最終了解這兩種致病菌的致病的分子生物化學(xué)機理。第二個內(nèi)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(nèi)它需要多腺苷聚合酶TRAMP復(fù)合體的激活，在細胞質(zhì)內(nèi)它需要SKI復(fù)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(jié)構(gòu)生物學(xué)的手段解析TRAMP以及SKI復(fù)合物的晶體結(jié)構(gòu)，并結(jié)合體外生化實驗以及體內(nèi)突變實驗揭示TRAMP和SKI復(fù)合物激活外切體降解底物RNA的分子機制。第三個內(nèi)容研究R-loop結(jié)構(gòu)影響基因組穩(wěn)定性的生化機理。研究發(fā)現(xiàn)，DNA轉(zhuǎn)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(jié)構(gòu)）可以導(dǎo)致基因組非穩(wěn)性及相關(guān)疾病的發(fā)生?；谶@個全新的發(fā)現(xiàn)，研究將運用遺傳學(xué)、細胞生物學(xué)、分子生物學(xué)和生物化學(xué)等多種方法進一步闡明R-loop結(jié)構(gòu)及新生RNA影響基因組穩(wěn)定性的生物化學(xué)機制，從而在此基礎(chǔ)上設(shè)計方法來干擾和避免R-loop結(jié)構(gòu)形成，為相關(guān)基因組非穩(wěn)性疾病的預(yù)防和治療提供理論基礎(chǔ)和可能性。另外，第四個內(nèi)容將建立生物信息學(xué)平臺，服務(wù)于研究所不斷增長的科學(xué)運算和科研信息管理、分析和應(yīng)用等方面的需求。

關(guān)鍵詞：新生物化學(xué)機制 重要疾病 基礎(chǔ)生命活動 病原菌 致病分子機理 RNA降解 結(jié)構(gòu)生物學(xué) 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

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