Multimerization of human immunodeficiency virus type 1 gag promotes its localization to barges, raft-like membrane microdomains
Multimerization of human immunodeficiency virus type 1 gag promotes its localization to barges, raft-like membrane microdomains
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DOI：
10.1128/jvi.75.17.7913-7924.2001
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发表时间：
2001-09-01
影响因子：
5.4
通讯作者：
Resh, MD
中科院分区：
文献类型：
--
作者：
Lindwasser, OW;Resh, MD
人类免疫缺陷病毒1型（HIV-1）的Gag多蛋白组织新生病毒粒子在感染细胞的质膜上的组装。在这里，我们证明了一个人口的Gag是存在于不同的筏状膜微域，我们称之为“驳船。“驳船的密度比标准筏高，最有可能是由于存在低聚Gag-Gag组装复合物。通过检查野生型和突变蛋白在Optiprep密度梯度上的浮选行为，绘制了负责驳船靶向的Gag蛋白的区域。N-豆蔻酰化的Gag是必要的协会与驳船。去除NC和p6结构域转移了大部分的加格从驳船到典型的筏分数。这些数据与肉豆蔻酰化的Gag蛋白的多聚化驱动Gag寡聚体结合成筏状驳船的模型一致。几条证据揭示了驳船协会的功能意义。首先，从病毒样颗粒中分离的Gag几乎完全局限于驳船。此外，野生型Gag与Fyn（10）Gag（一种含有Fyn N端序列的嵌合蛋白）的比较显示，Fyn（10）Gag对驳船的亲和力增加，颗粒产生增加了2至4倍。这些结果表明，协会的Gag筏状驳船膜微区在HIV-1的组装过程中起着重要的作用。
The Gag polyprotein of human immunodeficiency virus type 1 (HIV-1) organizes the assembly of nascent virions at the plasma membrane of infected cells. Here we demonstrate that a population of Gag is present in distinct raft-like membrane microdomains that we have termed "barges." Barges have a higher density than standard rafts, most likely due to the presence of oligomeric Gag-Gag assembly complexes. The regions of the Gag protein responsible for barge targeting were mapped by examining the flotation behavior of wild-type and mutant proteins on Optiprep density gradients. N-myristoylation of Gag was necessary for association with barges. Removal of the NC and p6 domains shifted much of the Gag from barges into typical raft fractions. These data are consistent with a model in which multimerization of myristoylated Gag proteins drives association of Gag oligomers into raft-like barges. The functional significance of barge association was revealed by several lines of evidence. First, Gag isolated from virus-like particles was almost entirely localized in barges. Moreover, a comparison of wild-type Gag with Fyn(10)Gag, a chimeric protein containing the N-terminal sequence of Fyn, revealed that Fyn(10)Gag exhibited increased affinity for barges and a two- to fourfold increase in particle production. These results imply that association of Gag with raft-like barge membrane microdomains plays an important role in the HIV-1 assembly process.