RNA结合域决定JDV Tat具有较强的激活能力

JDV Tat has Strong Transactivate Ability Because of its RNA Binding Domain

为分析JDV与BIV、HIV-1LTR和Tat相互激活能力差异的原因,在氨基酸序列对比及HIV-1Tat功能域划分的基础上构建了JH、HJ、JB、BJ几种嵌合Tat蛋白,并克隆到真核表达载体。将上述表达质粒与以JDV、BIV和HIV-1LTR为启动子,以luc为报告基因的质粒共转染Hela细胞,证实了三种不同Tat激活能力的差异主要来自其结合域RNA结合能力的差异,排除了结构域不完整和细胞因子缺乏造成JH不激活HIV-1LTR的可能性。

In order to find the cause of different transactivate abilities among JDV, BIV and HIV-1 Tat, four chimeric Tat cDNA expression constructs, JH, HJ, JB and B J, were generated with the crossover points at the boundary of activation and binding domains based on functional domain division of HIV- 1 Tat and amino acid sequence comparision among HIV-1, JDV and BIV Tat. These chimeric Tat proteins were co-transfected with JDV, BIV and HIV-1 LTR report plasmids in Hela. Transient assay showed that different transactivate abilities among JDV, BIV and HIV-1 Tat were mainly caused by different binding abilities of their binding domains. We further excluded some possibilities that may cause the poor transactivate ability of JH on HIV-1 LTR, such as incomplete functional domains and the lack of related cytokines.