HIV-induced membraneless organelles orchestrate post-nuclear entry steps
Résumé
Abstract HIV integration occurs in chromatin sites that favor the release of high levels of viral progeny, alternatively the virus is also able to coexist discreetly with the host. To uncover the HIV-1 DNA fate in the nuclear landscape, we directly tracked the viral DNA and the viral RNA by coupling HIV-1 ANCHOR technology with RNA FISH or MCP-MS2 RNA-tagging bacterial system. Our computational imaging analysis revealed that proviral forms are early located in proximity of the nuclear periphery of mitotic and non-mitotic cells. HIV-1 triggers the nuclear clustering of the host factor CPSF6, but yet its role is poorly understood. Our data show that CPSF6 clusters are part of HIV-induced membraneless organelles (HIV-1 MLOs). Interestingly, we observed that viral genomic RNAs and the integrase proteins are sequestered in CPSF6 clusters, in which the virus can reverse transcribe, while the late retrotranscribed DNA is excluded from these structures. HIV-1 MLOs are formed in the interchromatin space, indicating that they are not proviral sites, but orchestrate viral events prior to the integration step. We found transcription-competent proviruses localize outside HIV-1 MLOs, in LEDGF-abundant regions, known to be active chromatin sites. This study highlights single functional host-proviral complexes in their nuclear landscape, which is markedly restructured by HIV-1 to favor viral replication.