The terminal regions of adenovirus and minute virus of mice DNAs are preferentially associated with the nuclear matrix in infected cells

Abstract

The interaction of viral genomes with the cellular nuclear matrix was studied by using adenovirus-infected HeLa cells and minute virus of mice (MVM)-infected A-9 cells. Adenovirus DNA was associated with the nuclear matrix both early and late in infection, the tightest interaction being with DNA fragments that contain the covalently bound 5'-terminal protein. Replicative forms of MVM DNA were also found to be exclusively matrix associated during the first 16 to 20 h of infection; at later times viral DNA species accumulated in the soluble nuclear fraction at different rates, suggesting a saturation of nuclear matrix-binding sites. MVM DNA fragments enriched in the matrix fraction were also derived from the terminal regions of the viral genome. However, only the subset of fragments which possess a covalently bound 5'-terminal protein (i.e., DNA fragments in which the 5' palindromic DNA sequences are in the extended duplex rather than the hairpin conformation) were matrix associated. These observations suggest that the DNA-matrix interactions are, at least in part, mediated by the viral terminal proteins. Since these proteins have previously been shown to be intimately involved in viral DNA replication, our results further indicate that an association with the nuclear matrix may be important for viral genome replication and possibly also for efficient gene transcription.