Telenti Amalio, Martinez Raquel, Munoz Miguel, Bleiber Gabriela, Greub Gilbert, Sanglard Dominique, Peters Solange
Division of Infectious Diseases and Institute of Microbiology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
J Virol. 2002 Aug;76(15):7868-73. doi: 10.1128/jvi.76.15.7868-7873.2002.
Human immunodeficiency virus type 1 uses ribosomal frameshifting for translation of the Gag-Pol polyprotein. Frameshift activities are thought to be tightly regulated. Analysis of gag p1 sequences from 270 plasma virions identified in 64% of the samples the occurrence of polymorphism that could lead to changes in thermodynamic stability of the stem-loop. Expression in Saccharomyces cerevisiae of p1-beta-galactosidase fusion proteins from 10 representative natural stem-loop variants and three laboratory mutant constructs (predicted the thermodynamic stability [Delta G degrees] ranging from -23.0 to -4.3 kcal/mol) identified a reduction in frameshift activity of 13 to 67% compared with constructs with the wild-type stem-loop (Delta G degrees, -23.5 kcal/mol). Viruses carrying stem-loops associated with greater than 60% reductions in frameshift activity presented profound defects in viral replication. In contrast, viruses with stem-loop structures associated with 16 to 42% reductions in frameshift efficiency displayed no significant viral replication deficit.
1型人类免疫缺陷病毒利用核糖体移码来翻译Gag-Pol多蛋白。移码活性被认为受到严格调控。对来自270个血浆病毒粒子的gag p1序列进行分析，在64%的样本中发现了多态性的出现，这可能导致茎环热力学稳定性的改变。来自10个代表性天然茎环变体和3个实验室突变构建体（预测的热力学稳定性[ΔG°]范围为-23.0至-4.3千卡/摩尔）的p1-β-半乳糖苷酶融合蛋白在酿酒酵母中的表达表明，与具有野生型茎环（ΔG°，-23.5千卡/摩尔）的构建体相比，移码活性降低了13%至67%。携带与移码活性降低超过60%相关的茎环的病毒在病毒复制中表现出严重缺陷。相比之下，具有与移码效率降低16%至42%相关的茎环结构的病毒没有显示出明显的病毒复制缺陷。
