NUCLEAR TARGETING OF INCOMING HUMAN FOAMY VIRUS GAG PROTEINS INVOLVESA CENTRIOLAR STEP

The pathways used in the transport of retroviral genomes to the nucleu s are poorly identified, Analyzing the intracellular localization of i ncoming foamy viruses, we have found that the Gag antigens and the vir al genome accumulate in a distinct perinuclear domain identified as th e centrosome, Colchicine treatment completely abolished pericentriolar targeting of human foamy virus (HFV) proteins, suggesting a role for microtubules in the transport of the incoming viral proteins to the ce ntrioles, Finally, we demonstrate that, similarly to human immunodefic iency virus DNA, HFV DNA can enter the nucleus of G(1)/S-phase-arreste d cells, although no viral gene expression can be observed. Recent obs ervations have demonstrated that foamy viruses have several features n ot shared by other retroviruses, The intracellular route of the incomi ng Gag antigens may constitute a new specificity of this class of viru ses.