3rd Conf Retro and Opportun Infect. 1996 Jan 28-Feb 1;:168. Unique
Vpr is a small amino acid protein encoded by the human immunodeficiency
virus type 1 (HIV-1). Vpr prevents the proliferation of HIV-1-infected
cells by causing cells to accumulate in the G2 stage of the cell
cycle,and is a cytostatic, rather than cytotoxic agent. the accumulation
in G2 is mediated by the ability of Vpr to prevent activation of the
mitotic cyclin-dependant kinase. However, the mechanism of mitotic block
is different from normal G2 DNA damage checkpoint control. Although Vpr
expressing T-cells do not pass through mitosis, they continue to
synthesize DNA and increase in ploidy. Thus HIV-1 encodes a protein
which can decouple S phase from mitosis in human cells. We will show
data that suggest that one role of Vpr is to maximize viral production
by manipulation of the cell cycle in the face of cytolysis in vivo.
Cyclin-Dependent Kinases/METABOLISM Enzyme Activation G2 Phase Gene
Products, vpr/*PHYSIOLOGY HIV Infections/*METABOLISM/PATHOLOGY
HIV-1/*GENETICS Human Mitosis Ploidies ABSTRACT