title: Nuclear import of APOBEC3F-labeled HIV-1 preintegration complexes.
abstract: Human cytidine deaminases APOBEC3F (A3F) and APOBEC3G (A3G) are host factors that incorporate into virions and restrict virus replication. We labeled HIV-1 particles with yellow fluorescent protein (YFP)-tagged APOBEC3 proteins and examined their association with preintegration complexes (PICs) in infected cells. Labeling of PICs with A3F-YFP, and to a lesser extent A3G-YFP, could be used to visualize PICs in the nuclei, which was dependent on nuclear pore protein Nup153 but not TNPO3. We show that reverse transcription is not required for nuclear import of PICs, indicating that a viral core uncoating event associated with reverse transcription, and the central DNA flap that forms during reverse transcription, are not required for nuclear import. We also quantify association of cytoplasmic PICs with nuclear envelope (NE) and report that capsid mutations that increase or decrease core stability dramatically reduce NE association and nuclear import of PICs. In addition, we find that nuclear PICs remain close to the NE and are not distributed throughout the nuclei. These results provide tools for tracking retroviral PICs in infected cells and reveal insights into HIV-1 replication.
authors.affiliation: Viral Mutation Section and Viral Recombination Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Burdick
authors.forename: Wei-Shau
authors.initials: WS
authors.lastname: Hu
authors.forename: Vinay K
authors.initials: VK
authors.lastname: Pathak
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D043525:Cytosine Deaminase / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D008164:Luminescent Proteins / Q000378:metabolism; D046912:Multiprotein Complexes / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009685:Nuclear Envelope / Q000378:metabolism; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism; D014758:Viral Core Proteins / Q000235:genetics; D016662:Virus Integration / Q000235:genetics / Q000502:physiology*; D014779:Virus Replication / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D008164:Luminescent Proteins; D046912:Multiprotein Complexes; C079377:NUP153 protein, human; D028861:Nuclear Pore Complex Proteins; D014758:Viral Core Proteins; C054562:yellow fluorescent protein, Bacteria; C492906:APOBEC3F protein, human; D043525:Cytosine Deaminase
keywords: early events; microscopy; retrovirus