Olsen H S, Beidas S, Dillon P, Rosen C A, Cochrane A W
Department of Molecular Oncology and Virology, Roche Research Center, Nutley, New Jersey 07110-1199.
J Acquir Immune Defic Syndr (1988). 1991;4(6):558-67.
The human immunodeficiency virus type 1 (HIV-1) Rev protein is a positive posttranscriptional regulator of viral structural gene expression and essential for virus replication. Rev mediates its effects through interaction with an RNA target sequence, the Rev responsive element (RRE), present within the env mRNA. Previous studies have shown that the basic stretch of amino acids are required for Rev's ability to bind RNA, whereas residues present near the carboxy terminus are essential for full biological activity. Deletion mutagenesis was used to define the minimal domain required for RNA binding and function. We found that amino acids 8 through 67 confer full binding activity, whereas full biological activity requires the presence of residues 8 through 83. The minimal RNA binding sequence of HIV-1 Rev also interacts and functions with the HIV-2 and SIV RRE elements, indicating that the same domain is responsible for the biological activity with different, but related viruses. Mutational analysis of the RRE was also carried out in an effort to further define elements crucial for its function. Our findings indicate that interaction with Rev involves a stretch of three G nucleotides present at the base of a stem loop structure previously shown to be critical for Rev binding. These results suggest that the high degree of secondary structure of the RRE RNA may serve as a guide to bring Rev in contact with a primary nucleotide sequence required for stable protein-RNA association.
1型人类免疫缺陷病毒（HIV-1）Rev蛋白是病毒结构基因表达的一种正性转录后调节因子，对病毒复制至关重要。Rev通过与env mRNA中存在的一个RNA靶序列即Rev反应元件（RRE）相互作用来介导其效应。先前的研究表明，氨基酸的碱性区域是Rev结合RNA能力所必需的，而羧基末端附近的残基对于完全的生物学活性至关重要。采用缺失诱变来确定RNA结合和功能所需的最小结构域。我们发现，第8至67位氨基酸赋予完全的结合活性，而完全的生物学活性则需要存在第8至83位残基。HIV-1 Rev的最小RNA结合序列也能与HIV-2和SIV的RRE元件相互作用并发挥功能，这表明同一结构域对不同但相关的病毒具有生物学活性。我们还对RRE进行了突变分析，以进一步确定对其功能至关重要的元件。我们的研究结果表明，与Rev的相互作用涉及位于一个茎环结构底部的一段三个G核苷酸，先前已证明该茎环结构对Rev结合至关重要。这些结果表明，RRE RNA的高度二级结构可能作为一种引导，使Rev与稳定的蛋白质-RNA结合所需的一级核苷酸序列接触。
