Effects of stabilization of the gp41 cytoplasmic domain on fusion activity and infectivity of SIVmac239.
Effects of stabilization of the gp41 cytoplasmic domain on fusion activity and infectivity of SIVmac239.
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gp41 胞质结构域的稳定对 SIVmac239 融合活性和感染性的影响。
DOI：
10.1089/aid.2010.0321
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发表时间：
2011
影响因子：
1.5
通讯作者：
Compans,RichardW
中科院分区：
文献类型：
--
作者：
Vzorov,AndreiN;Compans,RichardW
我们研究了将预测会影响三聚体稳定性的特定序列引入SIV Env蛋白的CT结构域的效果。在CT域(45aa)增加Gcn4相关序列的两个结构物3HBa1和3HBaa增强了感染性，并且在融合活性和三聚体稳定性方面存在差异。另一种构造物3HBii显示出非常稳定的三聚体结构。含有3HBii的假型病毒粒子在缺乏合胞体形成的情况下仍具有感染性。相反，3HBai和3HBaa导致了广泛的合胞体形成，其三聚体结构不太稳定。我们观察到三聚体稳定性和融合活性之间呈负相关，但合胞体形成活性和感染性之间没有相关性。定量细胞-细胞融合分析、Env掺入分析、CD4结合测定胞外结构域构象和CCR5阻断实验表明，经Env CT修饰的病毒对融合活性和感染性有不同的影响。与CD4相互作用的差异不受三聚体稳定性的影响，也与融合活性或感染性无关。结果表明，CT结构域稳定性的变化可以显著影响Env外部结构域的功能活性，并可能影响病毒的生物学特性。
We investigated the effects of introducing specific sequences that are predicted to affect trimer stability into the CT domain of the SIV Env protein. Two constructs, 3HBai and 3HBaa, with additional GCN4-related sequences in the CT domain (45 aa) had enhanced infectivity, and differed in their fusion activity and trimer stability. Another construct, 3HBii, exhibited a very stable trimeric structure. Pseudotyped virions containing 3HBii retained infectivity despite the lack of syncytia formation. In contrast, 3HBai and 3HBaa, which caused extensive syncytia formation, had a less stable trimeric structure. We observed an inverse correlation between trimer stability and fusion activity but no correlation between syncytia formation activity and infectivity. Quantitative cell–cell fusion assays, analysis of Env incorporation, measurement of ectodomain conformation by CD4 binding, and CCR5 blocking assays indicated differential effects on fusion activity and infectivity of the viruses with Env CT modifications. Differences in interaction with CD4 were not affected by trimer stability and were not related to fusion activity or infectivity. The results indicate that changes in the stability of the CT domain can have significant effects on functional activities of the Env external domain and can impact viral biological properties.