Premature Stop Codon at Residue 101 within HIV-1 Rev Does Not Influence Viral Replication of Clade BC but Severely Reduces Viral Fitness of Clade B
Premature Stop Codon at Residue 101 within HIV-1 Rev Does Not Influence Viral Replication of Clade BC but Severely Reduces Viral Fitness of Clade B
复制标题
HIV-1 Rev内残基101处的过早终止密码子不影响进化枝BC的病毒复制，但严重降低进化枝B的病毒适应性
DOI：
10.1007/s12250-019-00179-0
复制
发表时间：
2019
影响因子：
5.5
通讯作者：
Yiming Shao
中科院分区：
文献类型：
--
作者：
Zheng Wang;Xiaolin Ji;Yanling Hao;Kunxue Hong;Liying Ma;Dan Li;Yiming Shao
HIV-1 Rev是一种辅助蛋白，在病毒mRNAs的核输出、稳定和翻译过程中起着关键作用。由于第101位过早终止密码子，HIV-1分支BC的REV经常显示16个氨基酸的截断。该终止密码子在BC分支中出现的频率最高，在B分支中出现的频率最低。为了发现这种截短对BC分支的REV活性和病毒复制的潜在生物学效应，我们分别构建了C-末端含有或不带有16个氨基酸的分支BC的REV表达载体，并在CRF07_BC感染性克隆中用Q替换了该终止密码子。我们发现，截短16个氨基酸对Bc支中REV的表达和活性没有影响。此外，终止密码子到Q的突变对BC分支的病毒复制也没有影响。接下来，为了研究这种截短对B分支的REV活性和复制能力的影响，分别构建了C端含有或缺失16个氨基酸的分支B的REV表达载体，并用B分支感染性克隆中的终止密码子替换了REV中101位的残基Q。结果发现，16个氨基酸的截短显著下调了REV的表达，并削弱了分支B的REV活性。此外，Rev内Q-to-Stop密码子的替换显著降低了B分支的病毒复制适合性。这些结果表明，Rev内第101位过早终止密码子对不同HIV-1分支之间的病毒复制产生不同的影响。
HIV-1 Rev is an accessory protein that plays a key role in nuclear exportation, stabilization, and translation of the viral mRNAs. Rev of HIV-1 clade BC often shows a truncation of 16 AAs due to a premature stop codon at residue 101. This stop codon presents the highest frequency in clade BC and the lowest frequency in clade B. In order to discover the potential biological effect of this truncation on Rev activity and virus replication of clade BC, we constructed Rev expression vectors of clade BC with or without 16 AAs within C-terminal separately, and replaced the stop codon by Q in a CRF07_BC infectious clone. We found that 16 AAs truncation had no effect on expression and activity of Rev in clade BC. Also, the mutation from the stop codon to Q had no effect on virus replication of clade BC. Next, to investigate the effect of this truncation on Rev activity and replication capacity of clade B, Rev expression vectors of clade B carrying or lacking 16 AAs in C-terminal were constructed respectively, and residue Q at position 101 within Rev was substituted by the stop codon in a clade B infectious clone. It was found that 16 AAs truncation significantly down-regulated Rev expression and impaired clade B Rev activity. Furthermore, a Q-to-stop codon substitution within Rev significantly reduced viral replication fitness of clade B. These results indicate that the premature stop codon at residue 101 within Rev exerts diverse impact on viral replication among different HIV-1 clades.