Document 0194
 DOCN  M9440194
 TI    Requirement of the Pr55gag precursor for incorporation of the Vpr
       product into human immunodeficiency virus type 1 viral particles.
 DT    9404
 AU    Lavallee C; Yao XJ; Ladha A; Gottlinger H; Haseltine WA; Cohen EA;
       Departement de Microbiologie et Immunologie, Faculte de; Medecine,
       Universite de Montreal, Quebec, Canada.
 SO    J Virol. 1994 Mar;68(3):1926-34. Unique Identifier : AIDSLINE
       MED/94149887
 AB    The human immunodeficiency virus type 1 (HIV-1) particles consists of
       two molecules of genomic RNA as well as molecules originating from gag,
       pol, and env products, all synthesized as precursor proteins. The
       96-amino-acid Vpr protein, the only virion-associated HIV-1 regulatory
       protein, is not part of the virus polyprotein precursors, and its
       incorporation into virus particles must occur by way of an interaction
       with a component normally found in virions. To investigate the mechanism
       of incorporation of Vpr into the HIV-1 virion, Vpr- proviral DNA
       constructs harboring mutations or deletions in specific
       virion-associated gene products were cotransfected with Vpr expressor
       plasmids in COS cells. Virus released from the transfected cells was
       tested for the presence of Vpr by immunoprecipitation with Vpr-specific
       antibodies. The results of these experiments show that Vpr is
       trans-incorporated into virions but at a lower efficiency than when Vpr
       is expressed from a proviral construct. The minimal viral genetic
       information necessary for Vpr incorporation was a deleted provirus
       encoding only the pr55gag polyprotein precursor. Incorporation of Vpr
       requires the expression but not the processing of gag products and is
       independent of pol and env expression. Direct interaction of Vpr with
       the Pr55gag precursor protein was demonstrated by coprecipitation
       experiments with gag product-specific antibodies. Overall, these results
       indicate that HIV-1 Vpr is incorporated into the nascent virion through
       an interaction with the Gag precursor polyprotein and demonstrate a
       novel mechanism by which viral protein can be incorporated into virus
       particles.
 DE    Animal  Cell Line, Transformed  DNA Mutational Analysis  Gene Products,
       gag/*METABOLISM  Gene Products, vpr/*METABOLISM
       HIV-1/GENETICS/*METABOLISM  Protein Binding  Protein
       Precursors/*METABOLISM  Proviruses/GENETICS/METABOLISM  Sequence
       Deletion  Support, Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.
       Transfection  Virion/METABOLISM  JOURNAL ARTICLE

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