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.
|Number of pages||5|
|Publication status||Published - 1993 Oct|
ASJC Scopus subject areas
- Cancer Research
- Molecular Biology