Characterization of HIV replication complexes early after cell-to-cell infection.
In this study, we have characterized the HIV DNA-containing replication complexes present in cells early after cell-to-cell infection, using sucrose gradient sedimentation and immunoprecipitation. Six hours after cell-to-cell infection, a cytoplasmic HIV replication complex sedimented as a large structure (320S). This replication complex was precipitated by antisera to three virus-coded enzymes (reverse transcriptase, integrase, protease), to the matrix protein (p17), and to cellular histones but not to the major capsid protein (p24). This replication complex was not associated with cell membranes and could not be dissociated into smaller discrete subunits, using detergents. Nuclear extracts from the same cell-to-cell infection contained a smaller (80S) complex that lacked reverse transcriptase and matrix protein (p17). Cytoplasmic replication complexes from a cell-free virus infection sedimented as 160S structures under identical conditions, as previously reported. Our results indicate that, following cell-to-cell transmission of HIV, all the HIV pol gene products, the matrix protein p17, and cellular histones are present in cytoplasmic replication complexes that are taking part in or have completed reverse transcription. Transportation of the cytoplasmic replication complex to the nucleus is associated with structural changes, including a reduction in size and altered protein composition.
Karageorgos
L
L
National Centre for HIV Virology Research, Institute of Medical and Veterinary Science, Adelaide, South Australia.
Li
P
P
Burrell
C
C
D001483:Base Sequence; D002467:Cell Nucleus / Q000382:microbiology; D004254:DNA Nucleotidyltransferases / Q000096:biosynthesis; D015683:Gene Products, gag / Q000096:biosynthesis; D015488:HIV Antigens / Q000096:biosynthesis; D016655:HIV Core Protein p24 / Q000096:biosynthesis; D016333:HIV Protease / Q000096:biosynthesis; D054303:HIV Reverse Transcriptase; D015497:HIV-1 / Q000502:physiology*; D006657:Histones / Q000378:metabolism; D006801:Humans; D019426:Integrases; D008969:Molecular Sequence Data; D012194:RNA-Directed DNA Polymerase / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000382:microbiology*; D014407:Tumor Cells, Cultured; D014764:Viral Proteins; D014779:Virus Replication; D054301:gag Gene Products, Human Immunodeficiency Virus
D015683:Gene Products, gag; D015488:HIV Antigens; D016655:HIV Core Protein p24; D006657:Histones; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1; D004254:DNA Nucleotidyltransferases; D019426:Integrases; D054303:HIV Reverse Transcriptase; D012194:RNA-Directed DNA Polymerase; D016333:HIV Protease