Long cellular repeats flanking a defective HTLV-I provirus: implication for site-targeted integration.
Retroviruses generally integrate as proviruses which are flanked by long-terminal repeats (LTRs) on both 5' and 3' ends. Since these LTRs are required for the efficient integration mediated by the viral integrase, it is believed that defective proviruses with a single LTR are normally formed by deletion after integration. However, we found no deletion of cellular sequences around the integration site of such a defective HTLV-1. Rather, we identified 99 bp-long direct repeats adjacent to both ends of the defective provirus. The repeated cellular sequences contained a potential poly(A) signal followed by a retroviral primer-binding-site-like sequence. The presence of the direct repeats of cellular sequences can be explained by the integration of the defective virus through homologous recombination between cellular and viral read-through sequences.
Institute for Virus Research, Kyoto University, Japan.
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S
Kubota
R
R
Furuta
M
M
Maki
H
H
Siomi
M
M
Hatanaka
D001483:Base Sequence; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D015458:Leukemia, T-Cell / Q000382:microbiology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011533:Proviruses / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*