Mechanism and factors that control HIV-1 transcription and latency activation  

调控HIV-1转录和潜伏激活的机制及相关因子(英文)

作　　者：Rong-diao LIU Jun WU Rui SHAO Yu-hua XUE 

机构地区：[1]School of Pharmaceutical Sciences,Xiamen University

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2014年第5期455-465,共11页浙江大学学报（英文版）B辑（生物医学与生物技术）

基　　金：Project supported by the National Natural Science Foundation of China (No.81201276);the Natural Science Foundation of Fujian Province (No.2012J05067),China

摘　　要：After reverse transcription, the HIV-1 proviral DNA is integrated into the host genome and thus subjected to transcription by the host RNA polymerase Ⅱ （Pol Ⅱ）. With the identification and characterization of human P-TEFb in the late 1990s as a specific host cofactor required for HIV-1 transcription, it is now believed that the elongation stage of Pol Ⅱ transcription plays a particularly important role in regulating HIV-1 gene expression. HIV-1 uses a sophisticated scheme to recruit human P-TEFb and other cofactors to the viral long terminal repeat （LTR） to produce full-length HIV-1 transcripts. In this process, P-TEFb is regulated by the reversible association with various transcription factors/ cofactors to form several multi-subunit complexes （e.g., 7SK snRNP, super elongation complexes （SECs）, and the Brd4-P-TEFb complex） that collectively constitute a P-TEFb network for controlling cellular and HIV-1 transcription. Recent progresses in HIV-1 transcription were reviewed in the paper, with the emphasis on the mechanism and factors that control HIV-1 transcription and latency activation.(1)反式激活蛋白(Tat)是病毒复制的重要因子,正性转录延伸因子b(P-TEFb)是Tat反式激活HIV-1转录所必需的特异性宿主细胞因子,其活性与HIV-1的转录密切相关。(2)在细胞内,无活性7SK snRNP复合体是功能性有活性P-TEFb的贮存和来源。在特定条件下,7SK snRNP复合体发生解离并释放出P-TEFb,从而刺激转录延伸。可以说,P-TEFb的活性受到严格的调控,维持着一种动态的平衡。(3)同时,P-TEFb还存在于一个具有超高转录活性的超级延伸复合体(SEC)中。Tat能将含有两个延伸因子P-TEFb和ELL2的SEC复合体募集至HIV-1长末端结构域(LTR),然后众多因子协同作用有效地增强HIV-1的转录作用。(4)溴区包含蛋白4(Brd4)像Tat一样,将P-TEFb募集至众多细胞基因的启动子区域,促进转录。Brd4也可激活基础水平的HIV-1转录,却对依赖Tat的HIV-1转录具有抑制作用,因为Brd4和Tat竞争性地与P-TEFb结合。(5)鉴于Brd4对Tat依赖性HIV-1转录的抑制作用,寻找能够抑制Brd4的小分子药物,激活HIV-1潜伏,结合高效抗逆转录病毒治疗(HAART),使得彻底根除HIV-1变成可能。Brd4的抑制剂JQ1就是这样的一种小分子,并且已被证明可以在多种细胞模型中激活HIV-1潜伏。

关 键 词：HIV-1 Transcriptional elongation RNA polymerase Ⅱ TAT P-TEFB 

分 类 号：R373[医药卫生—病原生物学] R346[医药卫生—基础医学]