HIV-1, VPR AND THE CELL-CYCLE

The human immunodeficiency virus 1 (HIV-1) is a complex retrovirus wit h more genes than most retroviruses. One of these extra genes codes fo r a protein called Vpr, which has recently been shown to prevent activ ation of the mitotic cyclin-dependent kinase and thereby prevent infec ted cells from undergoing mitosis and proliferating, Vpr also plays an important role in another property of HIV-1 that is unusual for a ret rovirus - its ability to enter the nucleus of a nondividing cell. Unde rstanding the interactions between HIV 1 and the cell cycle should lea d to new insights into both viral pathogenesis and basic cell biology.