HIV-1 nucleocapsid and ESCRT-component Tsg101 interplay prevents HIV from turning into a DNA-containing virus.

Abstract

HIV-1, the agent of the AIDS pandemic, is an RNA virus that reverse transcribes its RNA genome (gRNA) into DNA, shortly after its entry into cells. Within cells, retroviral assembly requires thousands of structural Gag proteins and two copies of gRNA as well as cellular factors, which converge to the plasma membrane in a finely regulated timeline. In this process, the nucleocapsid domain of Gag (GagNC) ensures gRNA selection and packaging into virions. Subsequent budding and virus release require the recruitment of the cellular ESCRT machinery. Interestingly, mutating GagNC results into the release of DNA-containing viruses, by promo-ting reverse transcription (RTion) prior to virus release, through an unknown mechanism. Therefore, we explored the biogenesis of these DNA-containing particles, combining live-cell total internal-reflection fluorescent microscopy, electron microscopy, trans-complementation assays and biochemical characterization of viral particles. Our results reveal that DNA virus production is the consequence of budding defects associated with Gag aggregation at the plasma membrane and deficiency in the recruitment of Tsg101, a key ESCRT-I component. Indeed, targeting Tsg101 to virus assembly sites restores budding, restricts RTion and favors RNA packaging into viruses. Altogether, our results highlight the role of GagNC in the spatiotemporal control of RTion, via an ESCRT-I-dependent mechanism.

• Authors: Célia Chamontin, Patrice Rassam, Mireia Ferrer, Pierre-Jean Racine, Aymeric Neyret, Sébastien Lainé, Pierre-Emmanuel Milhiet, Marylène Mougel
• Journal: Nucleic acids research (Nucleic Acids Res) Vol. 43 Issue 1 Pg. 336-47 (Jan 2015) ISSN: 1362-4962 [Electronic] England
• PMID: 25488808 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Chemical References

• DNA, Viral
• DNA-Binding Proteins
• Endosomal Sorting Complexes Required for Transport
• NCP7 protein, Human immunodeficiency virus 1
• Transcription Factors
• Tsg101 protein
• gag Gene Products, Human Immunodeficiency Virus

Topics

• Cell Line
• Cell Membrane (metabolism, ultrastructure, virology)
• DNA, Viral (biosynthesis)
• DNA-Binding Proteins (metabolism)
• Endosomal Sorting Complexes Required for Transport (metabolism)
• HIV-1 (genetics, metabolism, physiology)
• HeLa Cells
• Humans
• Reverse Transcription
• Sequence Deletion
• Transcription Factors (metabolism)
• Virion (metabolism)
• Virus Assembly
• Zinc Fingers
• gag Gene Products, Human Immunodeficiency Virus (chemistry, metabolism)