Madison Michaela K, Lawson Dana Q, Elliott Jennifer, Ozantürk Ayşe Naz, Koneru Pratibha C, Townsend Dana, Errando Manel, Kvaratskhelia Mamuka, Kutluay Sebla B
Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA.
Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey.
J Virol. 2017 Aug 10;91(17). doi: 10.1128/JVI.00821-17. Print 2017 Sep 1.
Recent evidence indicates that inhibition of HIV-1 integrase (IN) binding to the viral RNA genome by allosteric integrase inhibitors (ALLINIs) or through mutations within IN yields aberrant particles in which the viral ribonucleoprotein complexes (vRNPs) are eccentrically localized outside the capsid lattice. These particles are noninfectious and are blocked at an early reverse transcription stage in target cells. However, the basis of this reverse transcription defect is unknown. Here, we show that the viral RNA genome and IN from ALLINI-treated virions are prematurely degraded in target cells, whereas reverse transcriptase remains active and stably associated with the capsid lattice. The aberrantly shaped cores in ALLINI-treated particles can efficiently saturate and be degraded by a restricting TRIM5 protein, indicating that they are still composed of capsid proteins arranged in a hexagonal lattice. Notably, the fates of viral core components follow a similar pattern in cells infected with eccentric particles generated by mutations within IN that inhibit its binding to the viral RNA genome. We propose that IN-RNA interactions allow packaging of both the viral RNA genome and IN within the protective capsid lattice to ensure subsequent reverse transcription and productive infection in target cells. Conversely, disruption of these interactions by ALLINIs or mutations in IN leads to premature degradation of both the viral RNA genome and IN, as well as the spatial separation of reverse transcriptase from the viral genome during early steps of infection. Recent evidence indicates that HIV-1 integrase (IN) plays a key role during particle maturation by binding to the viral RNA genome. Inhibition of IN-RNA interactions yields aberrant particles with the viral ribonucleoprotein complexes (vRNPs) eccentrically localized outside the conical capsid lattice. Although these particles contain all of the components necessary for reverse transcription, they are blocked at an early reverse transcription stage in target cells. To explain the basis of this defect, we tracked the fates of multiple viral components in infected cells. Here, we show that the viral RNA genome and IN in eccentric particles are prematurely degraded, whereas reverse transcriptase remains active and stably associated within the capsid lattice. We propose that IN-RNA interactions ensure the packaging of both vRNPs and IN within the protective capsid cores to facilitate subsequent reverse transcription and productive infection in target cells.
最近的证据表明，变构整合酶抑制剂（ALLINIs）或整合酶（IN）内的突变抑制HIV-1整合酶（IN）与病毒RNA基因组的结合会产生异常颗粒，其中病毒核糖核蛋白复合物（vRNPs）偏心地定位在衣壳晶格之外。这些颗粒无感染性，并在靶细胞的早期逆转录阶段被阻断。然而，这种逆转录缺陷的基础尚不清楚。在这里，我们表明，来自ALLINI处理的病毒粒子的病毒RNA基因组和IN在靶细胞中过早降解，而逆转录酶仍然活跃并与衣壳晶格稳定结合。ALLINI处理的颗粒中异常形状的核心可以有效地被限制性TRIM5蛋白饱和并降解，这表明它们仍然由排列成六边形晶格的衣壳蛋白组成。值得注意的是，在感染了由IN内抑制其与病毒RNA基因组结合的突变产生的偏心颗粒的细胞中，病毒核心成分的命运遵循类似的模式。我们提出，IN-RNA相互作用允许病毒RNA基因组和IN都包装在保护性衣壳晶格内，以确保随后在靶细胞中的逆转录和有效感染。相反，ALLINIs破坏这些相互作用或IN中的突变导致病毒RNA基因组和IN过早降解，以及在感染早期逆转录酶与病毒基因组的空间分离。最近的证据表明，HIV-1整合酶（IN）通过与病毒RNA基因组结合在病毒粒子成熟过程中起关键作用。抑制IN-RNA相互作用会产生异常颗粒，病毒核糖核蛋白复合物（vRNPs）偏心地定位在锥形衣壳晶格之外。尽管这些颗粒包含逆转录所需的所有成分，但它们在靶细胞的早期逆转录阶段被阻断。为了解释这种缺陷的基础，我们追踪了感染细胞中多种病毒成分的命运。在这里，我们表明，偏心颗粒中的病毒RNA基因组和IN过早降解，而逆转录酶仍然活跃并稳定地结合在衣壳晶格内。我们提出，IN-RNA相互作用确保vRNPs和IN都包装在保护性衣壳核心内，以促进随后在靶细胞中的逆转录和有效感染。
