Stoichiometry of the antiviral protein APOBEC3G in HIV-1 virions
Stoichiometry of the antiviral protein APOBEC3G in HIV-1 virions
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DOI：
10.1016/j.virol.2006.10.036
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发表时间：
2007-04-10
期刊：
影响因子：
3.7
通讯作者：
Pathak, Vinay K.
中科院分区：
文献类型：
--
作者：
Xu, Hongzhan;Chertova, Elena;Pathak, Vinay K.
宿主胞苷脱氨酶APOBEC3G(A3G)在缺乏病毒编码的Vif蛋白(Delta vif病毒子)的情况下，通过将其掺入病毒粒子中抑制人类免疫缺陷病毒I型(HIV-1)的复制，至少部分是通过引起G-to-A超突变。为了深入了解A3G的抗逆转录病毒功能，我们测定了Delta vif病毒粒子中A3G分子的数量。我们结合了三种实验方法--反相高压液相色谱(HPLC)、闪烁邻近分析(SPA)和定量免疫印迹--来确定Delta vif病毒粒子中A3G与HIV-1衣壳蛋白的摩尔比。我们的研究表明，A3G被掺入Delta vif病毒粒子中的量与其在病毒产生细胞中的表达水平成正比，从活化的人外周血单个核细胞(PBMC)产生的Delta vif病毒粒子中A3G与GAG的比例约为1：439。根据以前对HIV-1 Gag在病毒粒子(1400-5000)中的化学计量比的估计，我们得出结论，大约有7(+/-4)个A3G分子被掺入到由人PBMC产生的Delta病毒粒子中。这些结果表明，只有几个A3G分子的病毒粒子掺入足以抑制HIV-1的复制。由爱思唯尔公司出版。
A host cytidine deaminase, APOBEC3G (A3G), inhibits replication of human immunodeficiency virus type I (HIV-1) by incorporating into virions in the absence of the virally encoded Vif protein (Delta vif virions), at least in part by causing G-to-A hypermutation. To gain insight into the antiretroviral function of A3G, we determined the quantities of A3G molecules that are incorporated in Delta vif virions. We combined three experimental approaches-reversed-phase high-pressure liquid chromatography (HPLC), scintillation proximity assay (SPA), and quantitative immunoblotting-to determine the molar ratio of A3G to HIV-1 capsid protein in Delta vif virions. Our studies revealed that the amount of the A3G incorporated into Delta vif virions was proportional to the level of its expression in the viral producing cells, and the ratio of the A3G to Gag in the Delta vif virions produced from activated human peripheral blood mononuclear cells (PBMC) was approximately 1:439. Based on previous estimates of the stoichiometry of HIV-1 Gag in virions (1400-5000), we conclude that approximately 7 (+/- 4) molecules of A3G are incorporated into Delta vif virions produced from human PBMCs. These results indicate that virion incorporation of only a few molecules of A3G is sufficient to inhibit HIV-1 replication. Published by Elsevier Inc.