HIV-1 Vpr促进Vif和APOBEC3G蛋白表达的研究

目的 观察人获得性免疫缺陷病毒蛋白Vpr对Vif蛋白和APOBEC3G蛋白表达水平的影响.方法 使用电转化法将携带Vif基因的酵母表达载体转化到裂殖酵母中,使用脂质体转染法将表达Vif蛋白、APOBEC3G蛋白的哺乳动物表达载体转染到可诱导稳定表达Vpr蛋白的哺乳动物HEK293细胞中;使用Western Blot方法检测目标蛋白表达水平的变化.结果 在裂殖酵母和哺乳动物细胞中,Vpr蛋白的表达能够提高细胞内的Vif蛋白的表达水平,在哺乳动物细胞中,Vpr蛋白对APOBEC3G蛋白的表达亦有促进作用,Vpr蛋白引起的Vif蛋白量的提高并没有导致APOBEC3G蛋白的减少.结论 Vpr蛋白具有调节细胞内蛋白表达的功能.

Enhanced protein production of Vif and APOBEC3G by HIV-1 Vpr

OBJECTIVE: Goal of this study was to test the potential regulatory effects of Vpr on Vif and Vif-mediated degradation of APOBEC3G. METHODS: The Vpr effect was first tested in a fission yeast RE007 strain that carries a single integrated copy of vpr gene in the chromosome and transformed with a vif-expressing plasmid. Similar tests were also carried out in a muristerone A vpr-inducing HEK293 mammalian cell line that were transfected with the plasmids expressing vif and/or APOBEC3G. Western Blot analyses were used to measure the corresponding protein levels under different experimental conditions. RESULTS: Expression of HIV-1 vpr appears to enhance the protein levels of Vif both in fission yeast and mammalian cells. A similar enhancement effect of APOBEC3G by Vpr was also detected in mammalian cells. Interestingly, however, the increased Vif protein level by Vpr did not result in more APOBEC3G degradation than without Vpr, indicating a potential regulatory effect of Vpr on Vif-mediated proteolysis of APOBEC3G. CONCLUSION: To our knowledge, this is the first report describing a potentially conserved and regulatory effect of HIV-1 Vpr on Vif and Vif-mediated protein degradation of APOBEC3G.