Schwartz S, Felber B K, Pavlakis G N
Human Retrovirus Section, National Cancer Institute-Frederick Cancer Research and Development Center, Maryland 21702-1201.
Virology. 1991 Aug;183(2):677-86. doi: 10.1016/0042-6822(91)90996-o.
We have analyzed the structure and expression of the HIV-1 vif and vpr mRNAs. The results revealed that the predominant vif and vpr mRNAs belong to the intermediate size class of HIV-1 mRNAs and that their expression is dependent on the presence of Rev protein. In addition, low levels of a small multiply spliced vpr mRNA were produced by HIV-1. cDNA cloning and expression of vpr cDNAs in eucaryotic cells revealed that high levels of Vpr were produced only from the intermediate-size mRNA in the presence of Rev. Thus, as demonstrated for the viral structural proteins, expression of Vif and Vpr is regulated by Rev. The arrangement of the splice sites and the Rev-RRE interaction are responsible for the regulation of viral expression, and especially for the switching from an early stage, producing only or primarily Tat, Rev, and Nef from multiply spliced mRNAs, to a late stage, leading to the production of Gag, Pol, Env, Vpu, Vif, and Vpr from unspliced and partially spliced mRNAs.
我们分析了HIV-1病毒感染因子（vif）和病毒蛋白R（vpr）mRNA的结构与表达。结果显示，主要的vif和vpr mRNA属于HIV-1 mRNA的中等大小类别，且它们的表达依赖于Rev蛋白的存在。此外，HIV-1产生了低水平的一种经过多次剪接的小vpr mRNA。vpr cDNA的克隆及其在真核细胞中的表达表明，只有在Rev存在的情况下，中等大小的mRNA才能产生高水平的Vpr。因此，正如病毒结构蛋白的情况所示，Vif和Vpr的表达受Rev调控。剪接位点的排列以及Rev与Rev反应元件（RRE）的相互作用负责病毒表达的调控，特别是从早期阶段（仅从多次剪接的mRNA产生或主要产生反式激活转录物（Tat）、Rev和负调控因子（Nef））到晚期阶段（从不剪接和部分剪接的mRNA产生 gag、pol、env、病毒蛋白U（Vpu）、Vif和Vpr）的转换。
