Adenovirus protein IX sequesters host-cell promyelocytic leukaemia protein and contributes to efficient viral proliferation.

The product of adenovirus type 5 (Ad5) gene IX, protein IX (pIX), is a multifunctional protein that stabilizes the viral capsid and has transcriptional activity. We show that pIX also contributes to the Ad5-induced reorganization of the host-cell nuclear ultrastructure: pIX induces the formation of specific and dynamic nuclear inclusions, and the host promyelocytic leukaemia (PML) protein, which is the main structural organizer of PML bodies, is stably relocated and confined within the pIX-induced inclusions late in infection. Our results suggest that Ad5 has evolved a unique strategy that leads to the sustained neutralization of PML bodies throughout infection, thereby ensuring optimal viral proliferation.