Berkhout B, Silverman R H, Jeang K T
Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
Cell. 1989 Oct 20;59(2):273-82. doi: 10.1016/0092-8674(89)90289-4.
Expression of the human immunodeficiency virus type 1 (HIV-1) genome is greatly dependent on the viral trans-activator protein Tat. Tat functions through the TAR element, which is represented in both viral DNA and RNA. At present, there is no definitive evidence that determines whether Tat acts through a DNA or RNA form of TAR. We have used an intramolecular mutagenesis approach to change selectively the RNA secondary structure of TAR without affecting its primary sequence. We show that a specific RNA secondary structure for TAR is needed for biological activity. Furthermore, transcripts that only transiently form a native TAR RNA hairpin, which is not maintained in the mature mRNA, are completely trans-activated by Tat, suggesting that TAR is recognized as a nascent RNA.
人类免疫缺陷病毒1型（HIV-1）基因组的表达在很大程度上依赖于病毒反式激活蛋白Tat。Tat通过TAR元件发挥作用，TAR元件存在于病毒DNA和RNA中。目前，尚无确凿证据确定Tat是通过DNA形式还是RNA形式的TAR起作用。我们采用分子内诱变方法，选择性地改变TAR的RNA二级结构而不影响其一级序列。我们发现TAR具有生物活性需要特定的RNA二级结构。此外，仅短暂形成天然TAR RNA发夹结构（在成熟mRNA中不保留）的转录本可被Tat完全反式激活，这表明TAR被识别为新生RNA。
