Cyclophilin A promotes HIV-1 reverse transcription but its effect on transduction correlates best with its effect on nuclear entry of viral cDNA.
Cyclophilin A promotes HIV-1 reverse transcription but its effect on transduction correlates best with its effect on nuclear entry of viral cDNA.
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DOI：
10.1186/1742-4690-11-11
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发表时间：
2014-01-30
期刊：
影响因子：
3.3
通讯作者：
Luban J
中科院分区：
文献类型：
--
作者：
De Iaco A;Luban J
人肽基脯氨酸异构酶亲环蛋白A （CypA）结合HIV-1衣壳（CA）并影响HIV-1复制周期的早期步骤。CypA调节HIV-1转导效率的机制尚不清楚。通过遗传手段或竞争性抑制剂环孢素A （CsA）破坏CypA与CA的结合，在一些细胞中降低了HIV-1转导的效率，但在其他细胞中没有。当CypA与特定的HIV-1 CA突变体（即A92E）结合被阻止时，某些细胞类型的转导显著增加。先前的研究表明，这种细胞类型特异性作用是由于一种显性作用的cypa依赖性限制因子。在这里，我们研究了CypA调节HIV-1转导效率的机制，使用27种不同的人类细胞系，32个HeLa亚克隆和几个先前表征的HIV-1 CA突变体。CypA与野生型CA或任何突变型CA结合的破坏，导致本文分析的所有细胞系中HIV-1逆转录的减少。然而，这种对逆转录的阻断与细胞类型特异性对转导效率的影响无关。2-LTR环是病毒cDNA核转运的标志，由逆转录产生，其水平与病毒的传染性密切相关。在这些细胞中，没有观察到细胞类型特异性对感染性的影响与稳态CypA蛋白水平之间的相关性。相反，正如衣壳命运测定所表明的那样，CsA以细胞类型特异性的方式将HIV-1 CA核心从明显的超稳定状态中释放出来。这些数据表明，尽管CypA在这里测试的所有条件下都能促进逆转录，但它对HIV-1传染性的影响与病毒cDNA进入细胞核的影响更密切相关。这些数据还支持了细胞类型特异性cypa依赖性限制因子通过延迟CA核心剥离和阻碍核进入来阻止HIV-1复制的假设。
The human peptidyl-prolyl isomerase Cyclophilin A (CypA) binds HIV-1 capsid (CA) and influences early steps in the HIV-1 replication cycle. The mechanism by which CypA regulates HIV-1 transduction efficiency is unknown. Disruption of CypA binding to CA, either by genetic means or by the competitive inhibitor cyclosporine A (CsA), reduces the efficiency of HIV-1 transduction in some cells but not in others. Transduction of certain cell types increases significantly when CypA binding to particular HIV-1 CA mutants, i.e., A92E, is prevented. Previous studies have suggested that this cell type-specific effect is due to a dominant-acting, CypA-dependent restriction factor. Here we investigated the mechanism by which CypA regulates HIV-1 transduction efficiency using 27 different human cell lines, 32 HeLa subclones, and several previously characterized HIV-1 CA mutants. Disruption of CypA binding to wild-type CA, or to any of the mutant CAs, caused a decrease in HIV-1 reverse transcription in all the cell lines analyzed here. This block to reverse transcription, though, did not correlate with cell type-specific effects on transduction efficiency. The level of 2-LTR circles, a marker for nuclear transport of the viral cDNA that results from reverse transcription, correlated closely with effects on infectivity. No correlation was observed between the cell type-specific effects on infectivity and the steady-state CypA protein levels in these cells. Instead, as indicated by a fate-of-capsid assay, CsA released the HIV-1 CA core from an apparent state of hyperstabilization, in a cell type-specific manner. These data demonstrate that, while CypA promotes reverse transcription under all conditions tested here, its effect on HIV-1 infectivity correlates more closely with effects on nuclear entry of the viral cDNA. The data also support the hypothesis that a cell-type specific CypA-dependent restriction factor blocks HIV-1 replication by delaying CA core uncoating and hindering nuclear entry.
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影响因子：
6.7
作者：
Kaul A;Stauffer S;Berger C;Pertel T;Schmitt J;Kallis S;Zayas M;Lohmann V;Luban J;Bartenschlager R
通讯作者：
Bartenschlager R
影响因子：
5.4
作者：
Braaten, D;Franke, EK;Luban, J
通讯作者：
Luban, J
影响因子：
5.4
作者：
Hatziioannou, T;Perez-Caballero, D;Bieniasz, PD
通讯作者：
Bieniasz, PD
影响因子：
11.4
作者：
Braaten, D;Luban, J
通讯作者：
Luban, J
影响因子：
3.3
作者：
De Iaco A;Luban J
通讯作者：
Luban J