       Document 0525
 DOCN  M9630525
 TI    Mutational analysis of cell cycle arrest, nuclear localization and
       virion packaging of human immunodeficiency virus type 1 Vpr.
 DT    9603
 AU    Di Marzio P; Choe S; Ebright M; Knoblauch R; Landau NR; Aaron Diamond
       AIDS Research Center, New York, New York, USA.
 SO    J Virol. 1995 Dec;69(12):7909-16. Unique Identifier : AIDSLINE
       MED/96079040
 AB    Human immunodeficiency virus type 1 Vpr is a virion-associated,
       regulatory protein that is required for efficient viral replication in
       monocytes/macrophages. The protein is believed to act in conjunction
       with the Gag matrix protein to allow import of the viral preintegration
       complex in nondividing cells. In cells, Vpr localizes to the nucleus.
       Recently, we showed that Vpr prevents the activation of p34cdc2-cyclin
       B. This results in arrest of Vpr-expressing cells in the G2/M phase of
       the cell cycle. Here, we use a panel of expression vectors encoding Vpr
       molecules mutated in the amino-terminal alpha-helical region, the
       central hydrophobic region, or the carboxy-terminal basic region to
       define the functional domains of the protein. The results showed cell
       cycle arrest was largely controlled by the carboxy-terminal basic domain
       of the protein. In contrast, the amino-terminal alpha-helical region of
       Vpr was required for nuclear localization and packaging into virions.
       The carboxy terminus appeared to be unnecessary for nuclear
       localization. In the alpha-helical region, mutation of Ala-30 to Pro
       resulted in a protein that localized to the cytoplasm. Surprisingly,
       fusion of Vpr to luciferase resulted in a molecule that failed to
       localize to the nucleus. In addition, we show that simian
       immunodeficiency virus Vpr, but not Vpx, induces G2 arrest. We speculate
       that Vpr has two sites for interaction with cellular factors: one in the
       alpha-helical region that specifies nuclear localization and one in the
       carboxy-terminal domain that is required for Cdc2 inhibition.
 DE    Amino Acid Sequence  Base Sequence  *Cell Cycle  Cell Line  Cell
       Nucleus/*VIROLOGY  DNA Mutational Analysis  DNA Primers  Gene Products,
       vpr/*BIOSYNTHESIS/CHEMISTRY/PHYSIOLOGY  *Genes, vpr  Human
       HIV-1/GENETICS/*PHYSIOLOGY  Immunoblotting  Macrophages/VIROLOGY
       Molecular Sequence Data  Monocytes/VIROLOGY  Polymerase Chain Reaction
       Protein Structure, Secondary  Recombinant Proteins/BIOSYNTHESIS
       Support, Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.  Transfection
       Virion/GENETICS/*PHYSIOLOGY  *Virus Replication  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

