Asamitsu Kaori, Omagari Katsumi, Okuda Tomoya, Hibi Yurina, Okamoto Takashi
Department of Molecular and Cellular Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan.
Department of Virology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan.
Genes Cells. 2016 Jul;21(7):706-16. doi: 10.1111/gtc.12375. Epub 2016 May 19.
The virus-encoded Tat protein is essential for HIV transcription in infected cells. The interaction of Tat with the cellular transcription elongation factor P-TEFb (positive transcriptional elongation factor b) containing cyclin T1 (CycT1) and cyclin-dependent kinase 9 (CDK9) is critical for its activity. In this study, we use the Fluoppi (fluorescent-based technology detecting protein-protein interaction) system, which enables the quantification of interactions between biomolecules, such as proteins, in live cells. Quantitative measurement of the molecular interactions among Tat, CycT1 and CDK9 has showed that any third molecule enhances the binding between the other two molecules. These findings suggest that each component of the Tat:P-TEFb complex stabilizes the overall complex, thereby supporting the efficient transcriptional elongation during viral RNA synthesis. These interactions may serve as appropriate targets for novel anti-HIV therapy.
病毒编码的Tat蛋白对于受感染细胞中的HIV转录至关重要。Tat与包含细胞周期蛋白T1（CycT1）和细胞周期蛋白依赖性激酶9（CDK9）的细胞转录延伸因子P-TEFb（正转录延伸因子b）的相互作用对其活性至关重要。在本研究中，我们使用了Fluoppi（基于荧光的蛋白质-蛋白质相互作用检测技术）系统，该系统能够对活细胞中生物分子（如蛋白质）之间的相互作用进行定量。对Tat、CycT1和CDK9之间分子相互作用的定量测量表明，任何第三个分子都会增强其他两个分子之间的结合。这些发现表明，Tat:P-TEFb复合物的每个组分都能稳定整个复合物，从而在病毒RNA合成过程中支持有效的转录延伸。这些相互作用可能成为新型抗HIV治疗的合适靶点。
